1

       1

       2

       3

       4              UNITED STATES OF AMERICA
                    FOOD AND DRUG ADMINISTRATION
       5    CENTER FOR BIOLOGICS EVALUATION AND RESEARCH
                               (CBER)
       6

       7

       8

       9

      10       BIOLOGICAL RESPONSE MODIFIERS ADVISORY

      11                  COMMITTEE MEETING

      12                    OPEN SESSION

      13

      14

      15

      16

      17

      18                8120 Wisconsin Avenue

      19                 Bethesda, Maryland

      20              Friday, November 13, 1998

      21

      22

                                                            2

       1    PARTICIPANTS:

       2       MEMBERS

       3       Dr. Julie M. Vose

       4       Dr. Richard A. Goldsby

       5       Dr. Hugh Auchincloss

       6       Dr. Carole B. Miller

       7       Dr. William M. O'Fallon

       8       Dr. W. French Anderson

       9       Dr. Richard E. Champlin

      10       Dr. Daniel R. Salomon

      11       Ms. Abbey S. Meyers

      12       Dr. Virginia C. Broudy

      13       Dr. Esperanza B. Papadopoulos

      14       Dr. Edward A. Sausville

      15       Ms. Gail Dapolito, Executive Secretary

      16       Ms. Rosanna L. Harvey, Committee Management
                      Specialist
      17

      18       CONSULTANTS
      19       Dr. P. Jean Henselee‑Downey

      20       Dr. Joanne Kurtzberg

      21       Dr. John E. Wagner

      22

                                                            3

       1    PARTICIPANTS (CONT'D):

       2       GUEST SPEAKER

       3       Dr. Richard J. O'Reilly

       4       FOOD & DRUG ADMINISTRATION (FDA) PARTICIPANTS

       5       Dr. Jay P. Siegel

       6       Dr. Patricia Keegan

       7       Dr. Gerald E. Marti

       8       Dr. Karen D. Weiss

       9       Dr. Stephen D. Litwin

      10

      11                    *  *  *  *  *

      12

      13

      14

      15

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                                                            4

       1                   C O N T E N T S

       2                                               PAGE

       3    Opening and Administrative Remarks            5

       4    Summary of NIH/CBER Hematopoietic            10
                      Stem/Progenitor Cell Work‑
       5              shop, September 10, 1998,
                      Gerald Marti, M.D., Ph.D.
       6              Office of Therapeutics
                      Research Review, CBER
       7
            Invited Presentations                        68
       8
                      P. Jean Henslee‑Downey, M.D.
       9              Richland Memorial Hospital

      10              Richard O'Reilly, M.D.
                      Memorial Sloan‑Kettering
      11              Cancer Center

      12              Joanne Kurtzberg, M.D.
                      Duke University Medical
      13              Center

      14    Committee Discussion                        202

      15
                            *  *  *  *  *
      16

      17                P R O C E E D I N G S

      18                                             (9:05 a.m.)
      19              MS. DAPOLITO:  Good morning and

      20    welcome to the 24th Meeting of the Biological

      21    Response Modifiers Advisory Committee.  My

      22    name is Gail Dapolito.  I am the committee

                                                            5

       1    executive secretary and the designated

       2    federal official for today's proceedings.

       3              The committee is meeting today to

       4    discuss issues related to allogeneic

       5    transplantation with a focus on haplo‑

       6    identical transplantation and other high‑risk

       7    transplantations.

       8              I would like to begin by

       9    introducing the committee members and other

      10    participants of today's discussions.

      11              If I could begin on my left, it is

      12    a pleasure to introduce and welcome two new

      13    committee members.  Dr. Daniel Salomon of the

      14    Scripps Research Institute and Dr. Esperanza

      15    Papadopoulos, Memorial Sloan‑ Kettering

      16    Cancer Center.

      17              Next is Dr. Carol Miller, the Johns

      18    Hopkins Oncology Center.  Joining us shortly,
      19    Dr. Hugh Auchincloss, Harvard Medical School,

      20    Massachusetts General Hospital; Dr. Richard

      21    Goldsby.  Dr. Goldsby is here somewhere,

      22    Amherst College; Dr. French Anderson,

                                                            6

       1    University of Southern California; the Chair

       2    Dr. Julie M. Vose, the University of

       3    Nebraska; Dr. Michael O'Fallon, the Mayo

       4    Clinic.

       5              Now, I have the distinct pleasure

       6    of announcing that Dr. O'Fallon has recently

       7    been elected to serve next year as the

       8    president elect of the American Statistical

       9    Association.  This is a very prestigious

      10    honor and we would like to offer Dr.

      11    O'Fallon our sincere congratulations.

      12              And I think I heard something about

      13    a Bronx Cheer.

      14              Proceeding around the table.  Dr.

      15    Jean Henslee‑Downey, University of South

      16    Carolina, Richland Memorial Hospital; Dr.

      17    Richard O'Reilly, Memorial Sloan‑Kettering

      18    Cancer Center; Dr. Joanne Kurtzberg, Duke
      19    University Memorial Center.

      20              The FDA Center for Biologics

      21    Evaluation and Research, Office of

      22    Therapeutics Research and Review is

                                                            7

       1    represented today by Dr. Stephen Litwin, Dr.

       2    Patrician Keegan, Dr. Karen Weiss, and Dr.

       3    Jay Siegel.

       4              We would like to request in

       5    consideration of the committee that you do

       6    not operate cellular phones in the room today

       7    and please put your pagers on silent mode.

       8              Dr. Vose, with your permission I'll

       9    read the conflict of interest statement.

      10              DR. VOSE:  Please.

      11              MS. DAPOLITO:  This announcement is

      12    made a part of the record at this meeting of

      13    the Biological Response Modifiers Advisory

      14    Committee on November 13, 1998.  Pursuant to

      15    the authority granted under the Committee

      16    Charter, the Director of the FDA's Center for

      17    Biologics Evaluation and Research has

      18    appointed Dr.  Jean Henslee‑Downey and Dr.
      19    Joanne Kurtzberg as temporary voting members

      20    for the Committee discussions.

      21              Based on the agenda made available

      22    and on relevant data reported by

                                                            8

       1    participating members and consultants, it has

       2    been determined that all financial interests

       3    in firms regulated by the Center for

       4    Biologics Evaluation and Research that may be

       5    affected by the committee's discussions have

       6    been considered.

       7              In accordance with 18 U.S.C. 208,

       8    Dr.  Esperanza Papadopoulos has been granted

       9    a general matters waiver which permits her to

      10    participate fully in the committee

      11    discussions.

      12              In regards to FDA's invited guest

      13    speaker, the Agency has determined that the

      14    service of Dr.  Richard O'Reilly is

      15    essential.  At the request of the Chair, Dr.

      16    O'Reilly has been invited to participate in

      17    the discussion of general scientific issues

      18    related to allogeneic transplantation.  The
      19    following reported interest are being made

      20    public to allow meeting participants to

      21    objectively evaluate any presentation and/or

      22    comments made by Dr. O'Reilly.

                                                            9

       1              Dr. O'Reilly is conducting a trial

       2    which involves the use of a product provided

       3    free of charge by a firm which could be

       4    affected by the committee discussions.  In

       5    the event that the discussions involve

       6    specific products or firms not on the agenda

       7    for which FDA's participants have a financial

       8    interests the participants are aware of the

       9    need to exclude themselves from such

      10    involvement and their exclusion will be noted

      11    for the public record.

      12              Screenings were conducted to

      13    prevent any appearance real or apparent of

      14    conflict of interest in today's committee's

      15    discussions.  Copies of the waiver addressed

      16    in this announcement are available by a

      17    written request under the Freedom of

      18    Information Act.
      19              With respect to all other meeting

      20    participants we ask in the interest of

      21    fairness that they address any current or

      22    previous financial involvement with any firm

                                                            10

       1    whose products they wish to comment upon.

       2              Dr. Vose, should I proceed with the

       3    open public hearing?

       4              DR. VOSE:  Please.

       5              MS. DAPOLITO:  We have received no

       6    prior requests to provide public comment.  At

       7    this time is there anyone present who would

       8    like to address the committee on matters

       9    before it today?  Dr. Vose, I see no on.

      10    I'll turn it over to you.

      11              DR. VOSE:  Okay.  Thank you.  We'll

      12    proceed then with the first item on the

      13    agenda, summary of the NIH/CBER Hematopoietic

      14    Stem Cell Progenitor Workshop and Dr. Marti.

      15          SUMMARY OF NIH/CBER HEMATOPOIETIC

      16            STEM CELL PROGENITOR WORKSHOP

      17              DR. MARTI:  Members of the Advisory

      18    Committee and staff, FDA, CBER colleagues,
      19    guests and press, I've been asked to give a

      20    15 to 20‑minute review of the recent meeting

      21    on peripheral stem cell and cord blood

      22    meeting that was held at the CBER and NIH.

                                                            11

       1              This meeting was essentially

       2    chaired and organized by Leanna Harveth who

       3    is unable to be here today due to an illness

       4    in her family.  And therefore I'm going to

       5    try and take her place.

       6              The meeting was entitled,

       7    Hematopoietic Stem/Progenitor Cell Products

       8    and it was a discussion of unrelated

       9    allogeneic placental umbilical cord blood and

      10    peripheral blood cell banking and

      11    transplantation.

      12              Next slide.  It was held on

      13    September 10th, 1998.  Next slide.  And it

      14    was sponsored by both CBER and NHLBI.  Next

      15    slide.  By the way, you have a set of these

      16    overviews in your blue folder.  The workshop

      17    objectives there were five.  The first one

      18    was to have an overview of the Federal
      19    Register notice which was published January

      20    20th and it was entitled "Request for

      21    Proposed Standards for Unrelated Allogeneic

      22    Peripheral and Placental/Umbilical Cord Blood

                                                            12

       1    Hematopoietic Stem/Progenitor Cell Products:

       2    Request for Comments."

       3              Next slide.  The second and third

       4    objectives are listed here.  The first was to

       5    discuss the current status of related and

       6    unrelated allogeneic peripheral blood

       7    hematopoietic stem/progenitor cell collection

       8    and transplantation.

       9              The third objective, discuss issues

      10    regarding the administration of cytokines to

      11    normal donors for mobilization of peripheral

      12    blood stem cells.

      13              Next slide.  And fourth to discuss

      14    the current status of unrelated allogeneic

      15    cord blood banking and transplantation.

      16              And the final objective was to

      17    discuss the status of professional voluntary

      18    standard development.
      19              Next slide.  There were four

      20    sessions.  The first session consisted of

      21    presentations of the review of the Federal

      22    Register notice by Dr. Harvath, and this was

                                                            13

       1    followed by a review of the transplantation

       2    registration data by Dr. Mary Horowitz and

       3    then the experience with normal donors and

       4    cytokine administration in the setting of a

       5    blood bank at M.D. Anderson was provided by

       6    Dr.  Anderlini.

       7              The next slide.  Session II

       8    consisted of experiences related to related

       9    allogeneic stem cell transplants at M.D.

      10    Anderson by Dr. Champlin and Washington

      11    University by Jon DiPersio.

      12              The unrelated allogeneic stem cell

      13    transplants peripheral based on the national

      14    marrow donor program, the NMDP experience

      15    that was provided by Dr. Dennis Confer.

      16              Next slide.  The third session

      17    primarily focused on the issues of blood

      18    banking of cord blood samples.  There was a
      19    presentation from Georgetown University on

      20    the multi‑center cord blood banking and

      21    transplantation study.  This is an umbrella

      22    IMD.  Then there was a presentation by Dr.

                                                            14

       1    Pablo Rubinstein from the New York Blood Bank

       2    that has the largest experience with cord

       3    blood in this country and the world.  And

       4    there was also a report from Duke University

       5    by Dr. Kurtzberg who is here today.  And then

       6    the more recent experience of the cord blood

       7    bank in St. Louis.

       8              The fourth and final session on the

       9    next slide was essentially a discussion of

      10    professional standards and these discussions

      11    emanated from representatives from AABB the

      12    American Association of Blood Banks by Dr.

      13    Haley, and then representatives from the

      14    transplant community, Dr. Shpall, Rowley, and

      15    LeMaistre.

      16              The next slide, please.  We'll now

      17    discuss briefly some of the points from the

      18    Federal Review Notice which was essentially a
      19    request for comments.

      20              Next slide.  For minimally

      21    manipulated unrelated allogeneic peripheral

      22    and placental/umbilical cord blood

                                                            15

       1    stem/progenitor cells intended for

       2    hematopoietic reconstitution, it may be

       3    possible ‑‑ next slide ‑‑ to develop product

       4    standards, establishment control and

       5    processing controls from existing scientific

       6    and clinical data.

       7              For those of you who find these

       8    Federal Register notices difficult to read,

       9    and it's taken me some 20 ‑‑ 15 or 20 years

      10    to learn to read them, I will repeat that

      11    sentence because I think that is the gold

      12    coin, the nugget of that paper to develop

      13    product standards, establishment controls and

      14    processing controls from existing scientific

      15    and clinical data.

      16              Also to issue guidance for

      17    establishment controls, processing controls

      18    and product standards; and to grant licensure
      19    for products certified as meeting issued

      20    standards.

      21              Next slide.  If the FDA determines

      22    that data are available to support the

                                                            16

       1    development of standards, the FDA intends to

       2    publicly announce such standards and

       3    licensure may be grated for products

       4    certified as meeting promulgated standards.

       5              Next slide.  If sufficient data are

       6    not available to develop standards, after a

       7    specified period of time unrelated allogeneic

       8    stem cell products would be subjected to IND

       9    and marketing application requirements.

      10              Next slide.  Now, continuing with

      11    peripheral blood stem cells, and I prefer

      12    saying "peripheral blood stem cells" to

      13    saying "peripheral blood hematopoietic

      14    stem/progenitor cells."  These are mobilized

      15    in normal allogeneic donors who are treated

      16    daily for five to six days with G‑CSF or

      17    GM‑CSF prior to the apheresis collections.

      18              Most stem cell collections
      19    experienced thus far have occurred with

      20    HLA‑identical sibling donor/recipient pairs.

      21              Next slide.  The reported advantage

      22    of peripheral stem cell products when

                                                            17

       1    contrasted to HLA‑identical sibling bone

       2    marrow donor/recipients during the first 100

       3    days post transplant appear to be the

       4    following two items:

       5              There is a decreased time to an

       6    absolute neutrophil count of greater than 500

       7    per microliter ‑‑ I guess that's a mistake.

       8    I don't think it should be "ML ‑‑ in four to

       9    five days, and there should be a decrease in

      10    inpatient days, pharmacy costs and blood

      11    products.

      12              Next slide.  There does not appear

      13    to be ‑‑ well, with regards to

      14    Graft‑verus‑Host Disease, the incidence of

      15    chronic Graft‑versus‑Host Disease is

      16    increased in peripheral blood stem cell

      17    recipients.  But the incidence of acute

      18    Graft‑verus‑Host Disease does not appear to
      19    be different between the two products.

      20              Next slide.  The International Bone

      21    Marrow Registry transplant and registry data

      22    analysis to one year post‑ transplant

                                                            18

       1    indicates a trend to 75 percent incidence of

       2    peripheral stem cell products compared to 45

       3    percent in bone marrow recipients.

       4              Also, the Washington University

       5    data at two years post‑transplant indicates a

       6    90 percent actuary incidence in the use of

       7    peripheral stem cells compared to 40 to 60

       8    percent with bone in bone marrow recipients.

       9              Next slide, please.  The peripheral

      10    stem cell grafts mismatched at one Antigen

      11    result in 100 percent incidence of chronic

      12    Graft‑verus‑Host Disease; 40 percent of these

      13    individuals are of the Grade 3 to 4.

      14              And there is an increased incidence

      15    in chronic Graft‑verus‑Host Disease

      16    associated with high CD34 cell counts and

      17    lymphocyte doses in these grafts.

      18              Next slide.  There are studies in
      19    progress to quantify the effects of lower

      20    cell doses.  It's been suggested that perhaps

      21    doses less than 10 to the sixth absolute CD34

      22    cells per kilograms and also different

                                                            19

       1    conditioning regimens.  One example being the

       2    FK506 prophylaxis on the incidence of

       3    Graft‑verus‑Host Disease.

       4              Next slide.  In the setting of

       5    unrelated allogeneic peripheral blood stem

       6    cell products, the National Marrow Donor

       7    Program is conducting a study of peripheral

       8    stem cells from unrelated allogeneic donors

       9    for a second donation subsequent to an

      10    initial bone marrow donation.

      11              So essentially these are going to

      12    be individuals who have already received a

      13    bone marrow graft from the program, but now

      14    are being requested for ‑‑ that same donor is

      15    being requested for a peripheral sample in

      16    the form of a lymphocyte transfusion.

      17              Next slide.  To date 119 requests

      18    for a second donation have been received.  As
      19    of August of 1998, 34 donors have received

      20    G‑CSF and 17 of these donors have had a one

      21    apheresis collection.

      22              Next slide.  And 15 donors have had

                                                            20

       1    two apheresis collections.  One donor had the

       2    G‑CSF administered, and no peripheral stem

       3    cells were collected.  And one donor received

       4    G‑CSF administration and the peripheral stem

       5    cells were collected, but they were not

       6    infused.

       7              Next slide.  In this particular

       8    setting the donors and recipients are being

       9    extensively studied.  These donors tend to

      10    develop ‑‑ I'm sorry, the National Marrow

      11    Donor Program intends to develop a similar

      12    study for unrelated peripheral stem cell

      13    products in the setting of the first

      14    donation.

      15              Next slide.  Some of the potential

      16    disadvantages of the peripheral stem cell

      17    product that's been noted in this program is

      18    the more frequent occurrence of the CMV
      19    viremia; the unknown risks associated with

      20    the increased Chronic Graft‑verus‑Host

      21    Disease; the unknown what the survival agency

      22    will be; and, of course, the new risks to

                                                            21

       1    normal donors in this program.

       2              Next slide.  Some of the short‑term

       3    safety issues for donors are bone pain,

       4    headache, fatigue, and nausea.  There are

       5    transient elevations of alkaline phosphatase

       6    and LDH and infrequent episodes of chest pain

       7    and fluid retention.

       8              Next slide.  It does require the

       9    placement of a central venus catheter,

      10    electrolytes, and fluid shifts are noted.

      11    There is obviously a leukocytosis and in some

      12    individual a thrombocytopenia.  I've been

      13    told that there was one incidence of a CVA

      14    and one instance of spontaneous rupture of

      15    the spleen.

      16              Next slide.  Long‑term safety

      17    issues for normal donors essentially remain

      18    unknown to present.  Next slide.  Some of the
      19    areas that were proposed for further research

      20    by the speakers at that meeting was to have

      21    the development of a normal donor registry to

      22    monitor long term.  "Long term" meaning ten

                                                            22

       1    years of normal donor receiving cytokines for

       2    the mobilization of cell products and also to

       3    have further studies of biologic and clinical

       4    effects of cytokines and apheresis procedures

       5    in normal donors.

       6              Next slide.  Also to continue to

       7    work on development of approaches to control

       8    Graft‑verus‑Host Disease to assess the

       9    stability of the peripheral stem cell

      10    engraftment to assess the functional effects

      11    of T‑cell depletion.

      12              Next slide.  And standardization of

      13    CD34 positive cell assays.  This is primarily

      14    thought to be flow cytometrically based and

      15    then standardization of tumor assays

      16    particularly directed at the presence of

      17    breast cancer and acute myelogenous leukemia.

      18              Next slide.  The third part of the
      19    meeting then turned its attention to the cord

      20    blood problem both in terms of banking and

      21    transplantation.  There is essentially a

      22    large umbrella type IND that has been

                                                            23

       1    developed at the FDA in combination with

       2    NHLBI.  This is multi‑centered.  The three

       3    banks are located at Duke, UCLA, and

       4    Georgetown, and the six transplant centers

       5    are located at Duke, University of Minnesota,

       6    UCLA, Fred Hutchinson, Indiana University,

       7    and Dana‑Farber.

       8              Next slide.  This study is going to

       9    entail a five‑year extensive study to

      10    characterize the cord and blood products and

      11    it's also going to measure transplant

      12    outcomes, results based upon a uniform

      13    protocol.

      14              It's my understanding that these

      15    protocols will be published in December 1998

      16    and made available on the NIH web site.

      17              Next slide.  The New York Placental

      18    Blood Program was the first to be
      19    established.  It is primarily solely for the

      20    use of unrelated allogeneic transplantation.

      21    It was established in 1992, has banked more

      22    than 7700 units, and has provided 700 units

                                                            24

       1    for transplantation.

       2              Next slide.  Results of the first

       3    562 consecutive transplants are in press in

       4    the New England Journal of Medicine and the

       5    speed of myeloid engraftments is associated

       6    primarily with graft cell dose.

       7              Next slide.  And transplant‑related

       8    events are associated with the patient's

       9    underlying disease, age, graft cell dose, HLA

      10    disparity, and transplant center meaning

      11    whether it was done in the U.S. or foreign.

      12              Next slide.  The St. Louis Cord

      13    Bank is a new member ‑‑ a new player.  They

      14    are community‑based, trying to bank unrelated

      15    cord blood specimens. It is primarily

      16    operated by obstetrician/nurse midwives who

      17    perform the collections.  However only 30

      18    percent of the samples are banked; 70 percent
      19    of the samples are deemed unacceptable for a

      20    variety of reasons.

      21              Next slide.  Areas proposed for

      22    future research include ex‑vivo expansion of

                                                            25

       1    cord blood subpopulations, adoptive cellular

       2    therapies, haplo‑identical, related cord

       3    blood transplants and to explore the use of

       4    cord blood with gene therapy.  Of course,

       5    that's already underway.  And the

       6    immunological vaccine development.

       7              Next slide.  The last session of

       8    the meeting consisted of a discussion of

       9    voluntary standards in this field.  The

      10    American Association of Blood Banks is an

      11    organization that was established in 1947.

      12    It currently represents 8500 individuals with

      13    2200 institutional members.  It has published

      14    standards for hematopoietic cells ‑‑

      15    progenitor cells since 1991.

      16              Next slide.  And it has invited

      17    participation of members of the following

      18    societies:  The AABB, the American Society of
      19    Apheresis, the FDA, the Foundation for

      20    Accreditation of Hematopoietic Cell Therapy

      21    (FACT), which represents ISHAGE, the

      22    International Society for Hematotherapy and

                                                            26

       1    Graft Engineering and also the American

       2    Society for Blood and Marrow Transplantation

       3    and the National Marrow Donor Program.  They

       4    all participate for standards development and

       5    revision.

       6              This group also includes two public

       7    members, an ethicist and a patient who has

       8    received hematopoietic progenitor cells as

       9    therapy.

      10              Next slide.  Basically what the

      11    AABB is doing is that they are in the process

      12    of revising their 1996 published standards to

      13    incorporate the ISO 9000 model for

      14    prospective comprehensive quality management

      15    program.

      16              That was the first time I heard the

      17    presentation of the ISO 9000 rules.  For

      18    several years now, I've had the occasion to
      19    drive through some of the parts of the

      20    Silicon Valley and Biotech areas in this

      21    country and you'll often see companies that

      22    will have a big sign up out in front that

                                                            27

       1    says, "ISO 9000 approved."  I think it's a

       2    very comprehensive approach to

       3    standardization and I predict that we will

       4    see more of it.

       5              Next slide.  FAHCT, the Foundation

       6    for Accreditation of Hematopoietic Cell

       7    Therapy was founded in 1996.  It has 900

       8    members and also the ISHAGE contributes about

       9    1000 individual members.  It's purpose is to

      10    establish standards for high‑quality medical

      11    and laboratory practice, to develop and

      12    implement voluntary inspection and

      13    accreditation.

      14              Next slide.  Their standards

      15    committee is composed of individuals from the

      16    ASBMT, ISHAGE, and FAHCT.  Next slide.  They

      17    expressed concerns regarding the FDA's

      18    proposed rule for facility registration and
      19    product listing.  Some of their reasons were

      20    that registration alone is not ‑‑ may not or

      21    does not improve safety.  The sequelae for

      22    registration are unknown and there was some

                                                            28

       1    concern that the FDA's ultimate intentions

       2    regarding this area are uncertain and that

       3    additional regulations have the potential to

       4    impede technological advance and compromise

       5    optimal patient care.

       6              Next slide.  The FAHCT Collection

       7    Center standards will include, or actually do

       8    include at this point in time, donor health

       9    screening including genetic disease;

      10    recording clinical outcome data.

      11              FAHCT has also proposed that the

      12    FDA grant deemed status to FAHCT and FAHCT

      13    acknowledges that some may choose not to

      14    participate in their voluntary accreditation

      15    program.

      16              Next slide.  This was the final

      17    discussion point, the importance of

      18    developing a single set of standards which
      19    are acceptable to all interested

      20    professionals in this field.

      21              FAHCT already has a 400‑page

      22    document outlining standards in almost all

                                                            29

       1    aspects of hematopoietic stem cell

       2    transplantation and I suspect we'll see some

       3    move toward that set of standards being

       4    combined with the ISO 9000 standards that

       5    AABB is proposing.  Thank you.

       6              DR. VOSE:  Thank you, Dr. Marti.

       7    Are there any questions or discussion

       8    regarding the workshop?

       9              We'll move on to Dr. Litwin.

      10                  FDA INTRODUCTION

      11              DR. LITWIN:  There's about a one‑

      12    or two‑minute hiatus while the projector

      13    catches up to us.

      14              Good morning.  I'm Dr. Stephen

      15    Litwin and the subject today as you've

      16    already heard are allogeneic transplants

      17    which I will present an introduction for

      18    CBER.  The focus is going to be on high‑risk
      19    allotransplants in which the high morbidity

      20    and the limited availability in the case of

      21    many donor/recipient pairs has led to a

      22    therapeutic dilemma for many patients.  The

                                                            30

       1    presentation will be in four sections.   In

       2    the first section in the background section I

       3    am going to present very briefly some of the

       4    comments and recommendations of previous

       5    biologic response modifier advisory

       6    committees.

       7              The second section will review the

       8    approaches, generally the expanding group of

       9    approaches to the management of high‑risk

      10    allotransplants.  That will be followed by a

      11    brief status report and the expectation is

      12    that these three introductory sections will

      13    serve as a frame of reference for the posing

      14    of a series of regulatory issues which are

      15    particularly relevant to allotransplants.

      16              And CBER staff looks forward to the

      17    committee's comments and insights and

      18    recommendations in this regard.
      19              Next slide, please.  The first

      20    Advisory Committee comments were actually in

      21    December of '94.  This slide excerpts them.

      22    I'll go through them briefly.  There was an

                                                            31

       1    emphasis that the goal of ‑‑ forward again ‑‑

       2    here we go ‑‑ there was an emphasis that the

       3    goal of less acute Graft‑verus‑Host Disease

       4    is basically and ultimately to improved

       5    survival.  Concurrent randomized trials were

       6    considered essential.  The primary endpoint

       7    of less acute Graft‑verus‑Host Disease

       8    measured in the first 100 days post

       9    transplant was acceptable, but it was highly

      10    contingent on the impact, the possible

      11    negative impacts on engraftment, on survival,

      12    on later events including infection,

      13    lympho‑proliferative disease.

      14              It was also emphasized there was a

      15    need to collect further data in the 6‑ to

      16    12‑month period that would constitute

      17    immunologic sustained hematologic and

      18    immunologic engraftment.  Including
      19    recommendations that immune functions could

      20    be measured first by collecting useful and

      21    detailed clinical information in this later

      22    period and by the use of selective, not

                                                            32

       1    panned, but rather selective groups of

       2    patients for immune function testing using

       3    the immune function tests that were best and

       4    most easily determined at the particular

       5    investigational site.

       6              It was also recommended that follow

       7    up be for at least one to two years.

       8              It was mentioned at this meeting

       9    that there were three randomized,

      10    concurrently controlled trials in the

      11    pipeline.  New trials have been added since

      12    then, but of these three trials, one has been

      13    closed due to a corporate decision, another

      14    has failed to show efficacy in preventing

      15    prophylactic ‑‑ prophylaxis of GVHD, and the

      16    third which was initiated at or about the

      17    time or shortly after this meeting is still

      18    under way.
      19              May I have the next slide, please?

      20    This issue was also discussed at the advisory

      21    committee meeting approximately six months

      22    ago by Dr.  Karen Weiss in a single proposal

                                                            33

       1    which dealt with a haplo‑identical

       2    allotransplant.  Protocol was discussed.

       3    That was a closed meeting and cannot be

       4    discussed further.

       5              The initial development of

       6    transplantation and strategies for

       7    transplantation, that is, mobilizing agents

       8    methods of separating cell populations and

       9    the devices for doing these were focused on

      10    autotransplantation.  And as the field has

      11    matured, it has shifted, it is currently

      12    shifting to allotransplantation.

      13              The technical issues for both are

      14    almost identical, and in fact, in some ways

      15    easier because normal donors are the target

      16    of immobilizing agents in allotrans‑

      17    plantation.  However, the regulatory issues

      18    are extremely different.  I have listed on
      19    the slide three of the licensed ‑‑

      20    FDA‑licensed‑related applications to, two

      21    mobilizing agents and one for a cell

      22    selection device, all in an

                                                            34

       1    autotransplantation setting.

       2              Next slide, please.  To pursue this

       3    further, the endpoints for autotrans‑

       4    plantation generally have been the purging of

       5    tumor cells and in one case reduced

       6    infusional toxicity.  A closely comparable

       7    engraftment has been required.  And late

       8    engraftment and even survival data has been

       9    collected, but there was no requirement that

      10    it be powered.

      11              In contrast in the allotransplant

      12    setting, the primary endpoint that has

      13    generally been offered is reduction of acute

      14    Graft‑verus‑Host Disease although comparable

      15    engraftment is also expected, there's greater

      16    latitude because the possibilities of a

      17    useful application would be greater.  And as

      18    far as the collection of later data, we have
      19    no current guidelines but simply the

      20    information gathered from the experience

      21    we've had with autotransplants.

      22              Next slide, please.  There is a

                                                            35

       1    serious concern about the limited

       2    availability of donors for many transplant,

       3    allotransplant recipients who need them.  The

       4    major sources of donors, the four major

       5    sources of donors are shown there.  In

       6    match‑related donors there is only about 25

       7    toward the out most, 30 percent opportunity

       8    for a recipient who needs a match‑related

       9    donor to obtain that.

      10              There's another 5 or 6 percent that

      11    can be obtained from related donors who have

      12    one antigen mismatch.  That would include

      13    partially matched ‑‑ PMRD, partially matched

      14    related donors.

      15              The unrelated donor source, for the

      16    most part, has been part of the National

      17    Marrow Donor program.  In the United States

      18    among caucasians the chances of getting a
      19    match through the National Marrow Donor

      20    program is approximately 50 percent.  But the

      21    possibilities are much less hopeful for many

      22    minorities in the United States.

                                                            36

       1              And, finally, the prospects of

       2    haploidentical donors who may be mismatched

       3    for two or three antigens and pose a much

       4    higher risk of the transplant situation is

       5    being actively explored.

       6              The morbidity of allotransplants

       7    depends on the increasing disparity of HLA

       8    among other factors.  This slide was shown

       9    actually six months ago.  It demonstrates the

      10    relationship both for related and unrelated

      11    grafts.  The major morbidity is acute graft

      12    versus host disease and engraftment failure.

      13    The relationships to chronic Graft‑verus‑Host

      14    Disease while present are probably a little

      15    less discernible.

      16              For related donors who are two

      17    antigen mismatched, the possibilities of

      18    grades II to IV, acute Graft‑verus‑Host
      19    Disease approaches 60 percent, or III to IV,

      20    the more severe categories close to 40

      21    percent.

      22              For comparable, unrelated grafts

                                                            37

       1    the figures are similar.  Although it's not

       2    shown on the listing haploidentical grafts

       3    with three antigen disparities have been

       4    reported to have grade II to IV acute Graft‑

       5    verus‑Host Disease incidences of 60 as high

       6    as 80 percent.

       7              The serious division in prognosis

       8    between matched‑related and all other were

       9    compared by ‑‑ this is allo, I hope I'm

      10    pronouncing that right.  In the Journal of

      11    Clinical Immunology last year this comparison

      12    of the match‑related ‑‑ this dichotomous

      13    comparison of the match‑related to all of the

      14    transplants was for three‑year overall

      15    transplant related mortality.  Among the

      16    match‑related transplants the three‑year

      17    mortality, morbidity was an acceptable 21

      18    percent.  Among all the other transplants it
      19    was over 50 percent.

      20              Next slide, please.  Given the

      21    limited availability of donors, and the high

      22    morbidities that some of these patients face

                                                            38

       1    for many allotransplants what kind of

       2    alternative therapeutic strategies are out

       3    there?  Rather than to try to encompass this

       4    which is a very large area, I have two

       5    examples.  In chronic myelogenous leukemia,

       6    the early phases for patients who are

       7    eligible the use of allogeneic transplants

       8    represents in many centers the primary

       9    modality.

      10              The use of the allogeneic

      11    transplant is considered by many to be

      12    curative.  These figures under match‑related

      13    donors from McGlave and Gratwohl are

      14    representative figures.  I just tried to take

      15    them including the whole range.  The Gratwohl

      16    figure is somewhat pessimistic compared to

      17    many of the others.

      18              For unrelated donors the data is
      19    very, very similar.  Autologous

      20    transplantation has a disadvantage of

      21    infusing back tumor cells and is not widely

      22    used.  The use of biologic agents such as

                                                            39

       1    interferon or interferon/hydroxyurea,

       2    although quite promising, lacks long‑term

       3    data.  So we do not know what the long‑term

       4    results or whether these will be actually

       5    curative.

       6              Next slide, please.  Turning to

       7    salvage therapy for acute myelogenous

       8    leukemia a far more grim situation, this is a

       9    comparison done in 1989 between different

      10    modalities by Keating.  This is in the

      11    post‑transplant situations so that each of

      12    the ‑‑ and the figures that are given there

      13    are in percent, so that each of those

      14    horizontal sets of figures will add up to 100

      15    percent.

      16              It can be seen that there are sharp

      17    advantage to allogeneic transplants which

      18    give among the highest complete response
      19    rate.  Keating has pointed out that there is

      20    a relationship between the overall survival

      21    and the initial response rate with the except

      22    of high dose ARA‑C in which there is somewhat

                                                            40

       1    of a disparity.

       2              It can be seen looking again at the

       3    allogeneic transplants that the response rate

       4    ‑‑ the complete response rate is quite good

       5    and better than comparable that the number of

       6    deaths are about the same as the other groups

       7    and the number of chemo resistant patients

       8    who are left is relatively small.

       9              Next slide, please.  In summary

      10    then, what are the alternatives to high‑dose

      11    chemotherapy with allotransplantation rescue.

      12    First, second and third line standard

      13    chemotherapy.  Avoid the high

      14    transplant‑related mortality that have a poor

      15    survival, autotransplants also have a lower

      16    transplant mortality, but you will reinfuse

      17    tumor cells back into the patient and there

      18    is a lack of graft versus tumor that is
      19    allogeneic effect.

      20              On biologic agents there is limited

      21    data.  Umbilical cord blood or expanded cells

      22    are still in early trials.  I will touch on

                                                            41

       1    that in a moment.  And we are left very often

       2    for many patients with a need for a

       3    haploidentical or partially‑match‑related

       4    donor transplant with it's high transplant

       5    ‑related mortality and acute

       6    Graft‑versus‑Host Disease.

       7              Next slide, please.  What then are

       8    the approaches?  This is second section to

       9    decreasing the allotransplant morbidity.

      10    These strategies can be divided into three

      11    major areas from the perspective of CBER.

      12    There is the most historic method, that is

      13    T‑cell depletion which will be abbreviated as

      14    TCD in many of the next few slides.  Both

      15    positive and negative selection which I'll

      16    expand on in a moment.

      17              There is the approach by

      18    manipulation of the stem cell source either
      19    by adding additional cells or by in some way

      20    manipulating the cell population.  Once

      21    again, I'll expand on that and finally ex

      22    vivo expansion and the use of cord blood

                                                            42

       1    cells.  I've grouped these together because

       2    in many protocols they're being tried within

       3    the same experimental laboratory.

       4              Next slide, please.  I'll start

       5    with T‑cell depletion, TCD.  T‑cell depletion

       6    has been used now for well over 20 years.  It

       7    remains very controversial as a therapy.  We

       8    have several experts here and I think we'll

       9    hear some comments later on.

      10              The major questions are really how

      11    best to do this, that is, which of the many

      12    techniques should be used.  Does it provide

      13    any overall patient benefit?  And I'm talking

      14    about survival.  And finally, what patient

      15    population should it be applied to?  And we

      16    really are ignorant about most of these area.

      17    The conventional wisdom is that T‑cell

      18    depletion will increase in engraftment
      19    failure and will decrease the incidence of

      20    acute Graft‑versus‑Host Disease both severity

      21    and incidence, but that the jury is still out

      22    on whether T‑cell depletion impacts survival

                                                            43

       1    for the patient.

       2              T‑cell depletion remains, however,

       3    widely used.  In this slide which is taken

       4    from the data from the International Bone

       5    Marrow Transplant Registry, it stashes data.

       6              The percentage of TCD by individual

       7    clinical entity is shown for matched‑related

       8    and for all other.  And it can be seen that

       9    those higher risk transplants, that is, where

      10    there's disparities ‑‑ HLA disparities among

      11    the other, use TCD in a much higher incidence

      12    as would be anticipated.  Within the study

      13    the range of T‑ cell depletion used was 16 to

      14    56 percent.

      15              Next slide, please.  Kernan in 1993

      16    looked at unrelated donors.

      17              This is data from the National

      18    Marrow Donor Program registry.  She found ‑‑
      19    they found, rather, that TCD was used in 21

      20    percent of cases and they emphasized the high

      21    incidence of graft failure, particularly

      22    secondary graft failure.

                                                            44

       1              Next slide, please.  Preti did a

       2    survey in 1993 of transplantation

       3    laboratories and he noted that 46 percent of

       4    all laboratories surveyed used one or another

       5    form of T‑ cell depletion.  The majority used

       6    pan‑T‑cell depletion techniques.

       7              Next slide, please.  And finally

       8    the consequences or the results of T‑cell

       9    depletion which I've already summarized are

      10    Maramount also from International Bone Marrow

      11    Transplant Registry data looked at hazard

      12    ratios.  The relative risks are shown to the

      13    right.  The enumerator here are those

      14    patients who had T‑cell depletion divided

      15    through by the denominator and those patients

      16    who did not.

      17              These are all match‑related

      18    allotransplants.  As you can see, the
      19    relative risk is much higher for graft

      20    failure, 9.29, that it is lower ‑‑ and that

      21    would be lower in the T‑cell depleted

      22    patients; for acute Graft‑verus‑Host Disease

                                                            45

       1    0.45 relative risk; and for treatment

       2    failure, once again, the results probably

       3    mean that the jury is still out.

       4              Next slide, please.  What are the

       5    ways of doing T‑cell depletion?

       6              Most laboratories use pan‑T‑cell

       7    depletion, that is all T‑cells are depleted.

       8    Selective depletion, there seems to be a lack

       9    of enthusiasm at least in the published

      10    literature at this point.  Selective

      11    depletion would be depletion of either the

      12    CD8 subset or the CD4 subset.

      13              The evaluation of T‑cell depletion

      14    remains very problematic.  There are a number

      15    of different methodologies which I will

      16    outline.  It is not clear that they are all

      17    the same.  Peripheral blood transplants are

      18    being used more frequently.  It has about
      19    ten‑fold higher number of T‑lymphocytes than

      20    does bone marrow.  I think Jerry Marti has

      21    mentioned the potential impact of this.

      22              And finally umbilical cord blood,

                                                            46

       1    UCB, and ex vivo expanded cells may have a

       2    very different brand of T cells as compared

       3    to bone marrow and peripheral blood.  We're

       4    uncertain about this, but the simple rule of

       5    one citizen, one vote, one T cell, one

       6    clinical impact would not seem to hold at

       7    this point until we get further information.

       8              Finally, the question of how much T

       9    cell depletion must be accomplished from a

      10    clinical point of view to have an impact

      11    either on the severity or the incidence of

      12    Graft‑verus‑Host Disease is very unclear from

      13    the published information.  In general, a

      14    consensus opinion would be that from 50,000

      15    to 400,000 CD3 positive cells per kilogram of

      16    body weight of the recipient would avoid

      17    acute Graft‑verus‑Host Disease, but that's a

      18    very wide range.
      19              Next slide, please.  Kernan, in a

      20    very widely‑quoted paper in 1986 looked at 31

      21    patients who had had T‑cell depletion and she

      22    observed that none of the patients who

                                                            47

       1    received under 100,000 clonable T cells

       2    suffered from Graft‑ verus‑Host Disease.  As

       3    I said, there were 31 patients, there were

       4    four who developed acute Graft‑verus‑Host

       5    Disease.

       6              These are Kernan's data taken from

       7    the paper, but they're reorganized by the

       8    patient group who had no GVHD which is the

       9    first vertical column or middle vertical

      10    column, that is 27 patients, and those who

      11    did, the four patients who did.  As you can

      12    see from the numbers, there is no ‑‑ we

      13    cannot make a distinction at this point

      14    between the absolute numbers and the relative

      15    numbers, the relative numbers being expressed

      16    as kilogram of body weight of the recipient.

      17    They both seem to show a relationship and a

      18    sharp difference.
      19              The average patient, and I'm

      20    talking about now the relative numbers,

      21    that's per kilogram of body weight received

      22    37,000 T cells and no‑GVHD group and close to

                                                            48

       1    240,000 T cells in the GVHD group.

       2              Unfortunately it is hard to

       3    determine the border between these two

       4    subsets that would help us understand ‑‑

       5    first of all, clonable T cells, by the way,

       6    were within this study IL2 PHA stimulated and

       7    cultured T cells.  And it is not clear what

       8    the cloning efficiency was.

       9              To determine the border between

      10    these two groups, that would help us discern

      11    the boundary for a threshold for inducing

      12    acute Graft‑verus‑Host Disease.  If one looks

      13    at the frequency and the distribution among

      14    the no‑GVHD group there were 27 persons, but

      15    there were four who had well over 100,000

      16    clonable T cells.  And among the GVHD group,

      17    the four, these figures were very high.  They

      18    had very high numbers of clonable T cells.
      19    So that it is impossible to pick out a border

      20    between these two which would be useful.

      21              Next slide, please.  And I think

      22    finally I should mention in the study that I

                                                            49

       1    had mentioned earlier by Maramount, it was

       2    noted that patients who received under a

       3    million T‑ lymphocytes and these were

       4    CD3‑marked T‑lymphocytes had a lower severity

       5    of Graft‑verus‑Host Disease.  I don't show

       6    the data here.

       7              What kind of processes are involved

       8    in T‑cell depletion?  Basically positive

       9    selection or negative selection.  Positive

      10    selection indicates that another population

      11    other than the T‑cells are selected for

      12    leaving the Infused 8, the transplant Infused

      13    8 at a much lower volume and number of cells

      14    and excluding many of the T cells from that

      15    selection which then becomes a T cell

      16    selection method.

      17              We've talked about the selection

      18    devices.  Centrifugation has been used, the
      19    results are very limited in terms of T‑cell

      20    depletion, density media, several have been

      21    used.  The figure of 85 percent reduction has

      22    been given, much less than a log.

                                                            50

       1              The two devices which are now being

       2    discussed for CD34 cell selection will

       3    deplete two and a half to three logs of T

       4    cells.  Counterflow elutriation

       5    centrifugation ‑based technique will deplete

       6    about two and a half logs.

       7              Next slide, please.  This is just

       8    an example of some published information on

       9    T‑cell depletion using the separate device.

      10    The figures of CD3 count before and after the

      11    selection method are shown.  You can see that

      12    links figure for peripheral blood is three

      13    logs; Bensinger two and a half ‑‑ 2.8, I'm

      14    sorry, for peripheral blood; Cottler‑Fox had

      15    figures for both peripheral blood which were

      16    very similar, 3.1 log and a higher T‑cell

      17    depletion in bone marrow.

      18              Next slide, please.  Negative
      19    selection involves the direct removal of T‑

      20    cells, the most historic of methods is the

      21    Sheep Red Cell Rosette Method with or without

      22    agglutinin‑NV log of T‑cell depletion shown

                                                            51

       1    here for the Sheep Rosette Method is without

       2    that a agglutinin and it's higher with it or

       3    with double rosetting.

       4              Many of the methods used now are

       5    antibody mediated.  That is antibody in the

       6    presence of compliment, antibody present on

       7    beads which can be magnetically removed or

       8    are dense so that they can be spun down.

       9    Antibody covalently linked to toxins panning

      10    which means that the antibody is covalently

      11    linked to the settling chamber is not widely

      12    used anymore.

      13              Let me call your attention to the

      14    last ‑‑ that is the use of positive and

      15    negative selection together which is now

      16    being employed in a number of protocols.

      17    That will achieve up to four logs of T‑cell

      18    depletion and is one of the active, though
      19    early areas being explored.

      20              Next slide, please.  The second

      21    approach is the manipulation of stem cells.

      22    Examples are given here.  They include:

                                                            52

       1    megadosing; highly purified stem cells

       2    referred to as HSC; the addition of

       3    facilitating cells, stromal cells, expanded

       4    stromal or mesenchymal cells; and in earlier

       5    times the actual use of mixed bone marrow and

       6    peripheral blood.

       7              I'll start with megadosing.  Next

       8    slide, please.  These were first described or

       9    popularized essentially by Aversa.  These

      10    next two slides are on results published in a

      11    very recent paper, a '98 paper.  He had two

      12    groups; one who were transplanted with

      13    peripheral blood, and another group who was

      14    transplanted with both peripheral blood and

      15    bone marrow.

      16              The figures aren't that disparate.

      17    There were 43 patients altogether.  You can

      18    see that the number of CD34 positive cells
      19    given and that's per kilogram of recipient

      20    body weight is much higher than usually used.

      21    It's 10 to 14 million.  Although certain

      22    centers now are moving up within approaching

                                                            53

       1    these numbers.

       2              There was extensive T‑cell

       3    depletion during these studies.  The number

       4    of CD3 positive T cells is 27,000 to 35,000

       5    in these groups.

       6              Next slide.  The next slide shows

       7    the results from the study of 43 patients.

       8    The median ANC, that's a thousand or was 11

       9    days.  For platelets reaching 50,000, 29

      10    days.  There were two patients who had

      11    primary graft failure, both were given

      12    secondary Infused 8 of cells and both seemed

      13    to engraft, though one did die.  And that's

      14    the Graft‑verus‑Host Disease and developed

      15    Graft‑verus‑Host Disease.  There was one case

      16    out of the 43, and that patient did die.  So

      17    we can assume that the Graft‑verus‑Host

      18    Disease was severe.
      19              There were 17 deaths, most of them

      20    due to infection.  Of the 43 there were 13

      21    relapses and 12 patients at a median follow

      22    up of 18 months were disease free.

                                                            54

       1              Next slide, please.  Highly

       2    purified stem cells were first developed in

       3    mice.  They represent a very small proportion

       4    in bone marrow and now have been extended to

       5    man and are entering early clinical studies.

       6    These cells contain most, probably all of the

       7    engrafting cells.  Their phenotype is

       8    relatively similar in mice and men.  Thy‑1.1

       9    lo, lineage negative, though there are some

      10    differences in antigens.  And in the mouse it

      11    has been shown that these cells will expand

      12    several thousand fold, that is, in the mouse

      13    under the appropriate cytokine conditions.

      14              Next slide, please.  Facilitating

      15    cells were first described by Drs. Sachs and

      16    Ildstat and a lot of the work is continuing

      17    in Dr. Ildstat's lab.  It is once again, a

      18    rare cell population.  The phenotype is T
      19    cell receptor negative, CD3 positive, CD8

      20    positive.  Also, these studies are also

      21    entering early clinical testing and it should

      22    be noted that both of these, both the HSC,

                                                            55

       1    highly‑purified stem cells, and the

       2    facilitating cells involve very extensive

       3    concomitant T‑cell depletion.

       4              Next slide, please.  Ex vivo

       5    expansion, the goals are to increase stem

       6    cells in patients who have a very low yield,

       7    so to permit them to get transplants.  To

       8    decrease the number of pheresis and

       9    potentially for putting away cells for the

      10    future.   It is also being applied in very

      11    exciting possibilities for expansion of

      12    umbilical cord blood cells which will deal

      13    with the problem of limited numbers.

      14              And it is also being looked at to

      15    increase the number of mature polymorphil

      16    nuclear leukocytes post‑transplant to

      17    decrease that window of infection, that is,

      18    the post‑transplant neutropenia.  The
      19    problems are that there are not any defined

      20    culture conditions or agreed‑upon culture

      21    conditions that maximize the results to date,

      22    and even more intrinsically there is no

                                                            56

       1    well‑define combination of cytokines.

       2              Also the engraftable cell that

       3    should be measured as a marker of what is

       4    happening is very uncertain.  In two of the

       5    reports of ex vivo expansion, in the face of

       6    a very, very marked increase in the total

       7    cell number the number of CD34 positive cells

       8    has remained about the same.  CFU have

       9    expanded, long‑term culture initiating cells,

      10    LTCIC, have been used, cobblestone assay,

      11    it's really an uncertain area.

      12              Next slide, please.  Cord blood has

      13    the problem of a limited number of

      14    engraftable cells.  There is reported delay

      15    platelet engraftment of 60 days or more.  And

      16    the biologic potential for both engraftment

      17    and complications are unknown, but data is

      18    rapidly being obtained and I'm sure we'll
      19    know more about this by next year.

      20              Next slide, please.  I'd like to

      21    provide for you a very short status report.

      22    We searched the IND/IDE files using as the

                                                            57

       1    search term "Peripheral Blood Stem Cells,

       2    Allogeneic."  I think you can see from the

       3    simple figures that we have given, these were

       4    51 IND/IDEs that we found.  That represents

       5    only 3 to 4 percent of the total amount of

       6    CBER activity over a period of about three

       7    years.  But as you can see from these figures

       8    the numbers are increasing.  Among the staff

       9    there is also the same subjective impression,

      10    that is, we're seeing a lot more activity in

      11    this are.

      12              I should point out that we're ‑‑

      13    that the only INDs or IDEs that CBER sees

      14    must involve a device or a drug, or an agent,

      15    or a monoclonal antibody, or some other

      16    experimental agent.  CBER essentially does

      17    not regulate straightforward allogeneic

      18    transplants if no experimental modality is
      19    involved.

      20              Next slide, please.  The features

      21    of the experimental design as interpreted

      22    from this group of studies ‑‑ of protocols

                                                            58

       1    that we looked at for the last three years

       2    were that they were, in general, single‑arm

       3    studies which would have to be compared to

       4    historical data.  They were small in size,

       5    they were single site, they were individual

       6    investigators, and they were early studies.

       7              Next slide, please.  The

       8    eligibility was determined in general by

       9    these studies by the institutional standards

      10    of care.  And generally a class of

      11    hematologic malignancies, that is, five or 6

      12    malignancies all scheduled for allotransplant

      13    by institutional protocols were involved in

      14    the studies rather than single clinical

      15    entities.

      16              Most of the data is from

      17    fully‑matched, matched‑related donor

      18    recipient pairs.
      19              Next slide, please.  In summary

      20    then, with respect to CBER activity direct

      21    T‑cell depletion remains the major

      22    experimental approach to high‑risk

                                                            59

       1    allotransplants that we're seeing.  T‑cell

       2    depletion with greater log reduction of the

       3    lymphocytes is being actively explored.

       4    Selective T‑cell depletion to date has not

       5    been convincing.

       6              Next slide, please.  A broader

       7    group of biologic approaches through

       8    Graft‑verus‑Host Disease are also being

       9    looked at.  They're in early phases and many

      10    of the newer techniques also produce very

      11    extensive T‑cell depletion which is going to

      12    make interpretation even more difficult as

      13    these cell populations are processed,

      14    expanded, cultured, and manipulated.

      15              Next slide, please.  To summarize

      16    the deficiencies, there are at the present

      17    time only two concurrently‑controlled late‑

      18    phase studies that remain open, one, a third,
      19    will start recently soon, we hope.

      20              There was a sharp absence of dose

      21    finding studies.  there is an absence of

      22    ability to identify those critical subsets or

                                                            60

       1    subpopulations in the allogeneic and fuseates

       2    that underlie biologic activities.

       3              And finally, there's a lack of

       4    trials involving high risk haploidentical,

       5    partial‑match‑ related transplants.

       6              Next slide, please.  The last

       7    section deals with a series of regulatory

       8    goals, regulatory questions really.  Our

       9    overall goals remain pretty much the same.

      10    That is, the decrease of acute

      11    Graft‑verus‑Host Disease, retain the early

      12    engraftment and sustain hematologic function;

      13    improve or retain graft versus tumor

      14    allogeneic effect and, of course, overall

      15    survival.

      16              The first regulatory question deals

      17    with the study population.  Should the study

      18    population to license strategies which
      19    improve allogeneic transplants be conducted

      20    on relatively healthier subjects or on

      21    higher‑risk, and less‑healthy populations?

      22              Next slide.  On the healthier

                                                            61

       1    populations they are often younger and have

       2    matched‑related donors.  There would be less

       3    background noise and so adverse events, in

       4    particular, but also activity would be easier

       5    to determine.  Concurrent unprocessed

       6    controls would be more available since the

       7    standard techniques using as well matched a

       8    donor as you can are far more ‑‑ far more

       9    frequent than would be those for high‑risk

      10    persons.  And so the possibilities of getting

      11    controls would be greater.

      12              The ability to collect long‑term

      13    data would also be improved because the study

      14    group would survive much longer than a

      15    higher‑risk population.

      16              It should also be mentioned that

      17    the risks may be unacceptable.  That is, in a

      18    population of such patients in whom a
      19    standard procedure, although risky, offers a

      20    substantial promise ‑‑ a very risky

      21    experimental procedure should be thought

      22    about very carefully.

                                                            62

       1              Next slide, please.  In terms of

       2    the high‑risk populations they were often

       3    older, they were often HLA mismatched and

       4    they often have higher stage disease and a

       5    lot of previous treatment.

       6              The reasons to look at such a

       7    population, which we already alluded to,

       8    would be first of all the dramatic unmet need

       9    that we have here.  The impact on survival

      10    may be more visible though in a shorter term.

      11              Control populations may not be

      12    feasible.  The number of patients who would

      13    be involved in these procedures are being

      14    involved in these procedures is quite small.

      15    And clinicians and physicians may be very

      16    resistant to taking the patient with such a

      17    high risk and not offering a modality that at

      18    least offers something such as T‑cell
      19    depletion in a controlled arm, or the

      20    possibility of a control arm.

      21              Next slide, please.  Also with

      22    respect to the study population a second

                                                            63

       1    question:  How narrowly focused should the

       2    study population be?  A single conditioning

       3    regimen, a single GVHD prophylaxis regimen,

       4    regulations are in concomitant medications.

       5              Should the group be stratified for

       6    a narrow Tcell dose range?  In general we see

       7    a very wide range since all the cells that

       8    can be appropriately collected on guidelines

       9    are usually infused.

      10              Should it be stratified for

      11    unrelated versus related donors, for HLA

      12    match?

      13              Next slide, please.  Endpoints.  In

      14    studies with concurrent controls and a

      15    primary endpoint of decreased acute

      16    Graft‑verus‑Host Disease or decreased

      17    morbidity in the transplant period, must

      18    survival and event‑free survival data be
      19    collected?  And if the answer is yes, I hope

      20    it is, is similar or superior survival of the

      21    treatment arm necessary?  If similar survival

      22    figures are necessary in any treatment arm,

                                                            64

       1    how similar should it be?  How much leeway

       2    should there be, how much worse could it

       3    possibly be and still be evaluated as a

       4    useful procedure.

       5              Next slide.  And finally,

       6    endpoints, should the primary endpoint be

       7    overall survival or event‑free survival, and

       8    should the study be powered to detect a

       9    difference in overall survival or event‑free

      10    survival.  And I'm restating what was really

      11    said on the last slide.

      12              Next slide, please.  Controls.  Are

      13    concurrent controls not only desirable but

      14    absolutely required?  If not, could you

      15    please comment on alternative experimental

      16    designs that might be available and which

      17    could be acceptable.

      18              Thank you.
      19              DR. VOSE:  Thank you, Dr. Litwin.

      20    Why don't we proceed with a short discussion

      21    or maybe questions for Dr. Litwin.  Dr.

      22    O'Reilly.

                                                            65

       1              DR. O'REILLY:  Yeah, just to make

       2    one comment, the estimates that you had for

       3    Graft‑verus‑ Host Disease for the mismatched

       4    circumstance are derived from a series that

       5    included both depleted and unmodified.  In

       6    the unmodified mode, the usual read for a

       7    Graft‑verus‑Host Disease in a two antigen

       8    disparate graft is 80 to 85 percent grade II

       9    to IV and for a three it's in excess of 90 to

      10    100 percent with very few, if any, long‑term

      11    survivors.  And I think that that's an

      12    important point when we're getting into this

      13    in the evaluation of these types of

      14    transplants because in very real terms a full

      15    haplotype unmodified graft is lethal and can

      16    be lethal in very few cells administered.

      17              DR. VOSE:  Any other comments or

      18    questions?
      19              DR. O'REILLY:  The source for that

      20    is Pat Beatty's study in the New England

      21    Journal and there are several other sources

      22    on it.

                                                            66

       1              DR. LITWIN:  There wasn't a

       2    question in that, was there, Richard?

       3              DR. O'REILLY:  No, no, but I think

       4    that's important because because I think that

       5    the barrier is more extreme than the figures

       6    that you presented suggested.

       7              DR. HENSLEE‑DOWNEY:  Although I

       8    think it's of interest that even in Pat

       9    Beatty's publication in the New England

      10    Journal of Medicine in 1985 which clearly

      11    showed in unmodified grafts that the

      12    incidence of Graft‑verus‑Host Disease would

      13    be in the 80 percent or above range.

      14              When he looked at patients

      15    transplanted in remission survival beyond two

      16    years was identical, and when one looked at

      17    all of the mismatched family donor

      18    transplants compared to matched sibling donor
      19    transplants.  So even then feasibility of

      20    performing haploidentical transplant was

      21    established if the patient was in good

      22    condition and could tolerate the transplant

                                                            67

       1    reasonably well.  Yeah, it's true, people

       2    forget it.

       3              DR. O'REILLY:  As far as I ‑‑

       4              DR. VOSE:  Can you just speak into

       5    the microphone?  I'm sorry, it's being

       6    recorded.

       7              DR. O'REILLY:  As far as I

       8    remember, the only ones that are comparable

       9    survival to the HLA matches were the one

      10    antigen disparate grafts.

      11              DR. HENSLEE‑DOWNEY:  No.  No,

      12    actually the whole group as a whole in

      13    remission patients ‑‑ I have the slide

      14    upstairs ‑‑ in remission patients only had

      15    similar survival as matched‑sibling donors.

      16              DR. O'REILLY:  Okay.

      17              DR. LITWIN:  I think we can all

      18    accept the fact that the risks, however, in
      19    mismatched transplants are substantial and

      20    that's our focus.

      21              DR. HENSLEE‑DOWNEY:  Absolutely.

      22              DR. VOSE:  I think we're scheduled

                                                            68

       1    for a break, but why don't we just go on to

       2    our presentations if that's okay with

       3    everybody.

       4              We'll just take a couple minute

       5    break to get everybody set up and go on with

       6    our guest presentations.

       7                   (Recess)

       8                INVITED PRESENTATIONS

       9              DR. VOSE:  We'll next proceed with

      10    the guest presentations and first Dr.

      11    Henslee‑Downey from the University of South

      12    Carolina is going to speak.  Jean.

      13              DR. HENSLEE‑DOWNEY:  Thank you.

      14    Well, it is a pleasure to be with you today

      15    and to discuss this topic that I've been

      16    actually working on for over a decade now.

      17    And I thought I would review some of the

      18    issues as well as share with you some of our
      19    own work in doing the haploidentical

      20    transplants.

      21              First slide, please.  Or I can do

      22    that.  And this just again looks at donor

                                                            69

       1    availability which is what has really driven

       2    our interests in performing haploidentical

       3    transplant.  And as previously stated the

       4    chance to find a match sibling donor is

       5    somewhere in the 25 percent range.

       6              The opportunity to find an

       7    unrelated donor through registries whether

       8    that be the adult volunteer registry or cord

       9    blood registries depends in large part on the

      10    HLA haplotypes of the person needing the bone

      11    marrow transplant and how frequently those

      12    haplotypes are expressed in the registry.

      13              However ‑‑ and Joanne Kurtzberg

      14    will talk about cord blood more later this

      15    morning ‑‑ the hope was that one could use

      16    more mismatching or tolerate more mismatching

      17    with cord bloods and therefore it would be

      18    easier to find donors.  This bar graph is
      19    somewhat complex because it does represent

      20    the fact that some individuals with very

      21    common HLA haplotypes will have 100 percent

      22    chance to find a donor and in fact today with

                                                            70

       1    more than 4 million donor in the registry,

       2    when an individual has a donor they often

       3    have many donors, even 600, 700, 800 donors,

       4    but that doesn't change the fact that there

       5    are some individuals who probably will never

       6    find a donor in the registry.

       7              And particularly individuals who

       8    represent unusual HLA combinations and these

       9    often represent people from ethnic groups or

      10    minority groups where their chance of finding

      11    an unrelated donor can be less than 5

      12    percent.  And for that reason many people in

      13    the field have continued to concentrate on

      14    trying to develop techniques to do

      15    haploidentical family donor transplants.

      16              Now, for some time in the field in

      17    general people have accepted the fact that

      18    one might do one antigen mismatched family
      19    member transplant.  However, this could still

      20    only be available if one did very careful

      21    extensive family typing and that is not often

      22    done.  But this donor may only be available

                                                            71

       1    to anywhere from 10 to maybe 25 percent of

       2    patients.  If one can tolerate a two antigen

       3    barrier, whether that be in the donor or in

       4    the patient, then the chance of finding a

       5    donor could go up to perhaps even 50 percent.

       6    But the donor that truly makes allogeneic

       7    marrow transplant readily and immediately

       8    available to almost every single patient in

       9    need of a transplant would be the

      10    haploidentical donor.

      11              Now, you need to understand that

      12    when we say that this donor is haploidentical

      13    it means that there is at least at three

      14    antigen mismatch in either the donor or the

      15    recipient, or both.  So it does get somewhat

      16    complex when we start to think about these

      17    haploidentical identical donors because we

      18    have to think bidirectionally.
      19              Now, we've already listened to the

      20    previous speaker who has very nicely pointed

      21    out the significant problems that have stood

      22    in the way of successful transplant outcomes

                                                            72

       1    and they include graft failure, acute and

       2    chronic Graft‑verus‑Host Disease and poor

       3    immune reconstitution.  And, certainly, this

       4    is ‑‑ these represent the most important

       5    early and late endpoints that must be studied

       6    in any trial to do mismatched transplants.

       7              Not listed here, but also of great

       8    importance, I believe, will be the goal

       9    standard and that is survival and

      10    disease‑free survival.

      11              Now, as previously stated, most

      12    people in the field have looked at forms of

      13    T‑cell depletion as a way of trying to

      14    overcome histocompatibility barriers.  And in

      15    this slide, it is my hope to kind of think

      16    about the broad approach to T‑cell depletion.

      17    And we know that outcomes, particularly these

      18    early endpoints engraftment or acute
      19    Graft‑verus‑Host Disease can be linked to the

      20    degree of T‑cell depletion that is performed

      21    so that if one does light T‑cell depletion

      22    and gives a fairly large T‑cell dose, then

                                                            73

       1    one can still see significant

       2    Graft‑verus‑Host Disease but also one often

       3    sees engraftment.

       4              As one tries to control acute GVHD

       5    through T‑ cell depletion unfortunately there

       6    is usually a loss of successful engraftment.

       7    And so a number of investigator have tried to

       8    look at trying to get in between on this

       9    spectrum of T‑cell depletion and then look at

      10    other treatment modalities that might help

      11    you improve engraftment as well as improve

      12    the control of GVHD.

      13              For example, certainly host

      14    conditioning can be critical in the success

      15    of engraftment and it can even correct,

      16    perhaps, graft failure when one is even in

      17    this range of T‑cell depletion.  Donor

      18    disparity also has clearly been associated
      19    with poor graft engraftment.  Some

      20    investigators are now exploring what was

      21    mentioned, and that is increasing the stem

      22    cell dose or using growth factors to enhance

                                                            74

       1    engraftment.

       2              On the flip side, if one uses less

       3    T‑cell depletion as a part of improving

       4    engraftment, you may still deal with a lot of

       5    GVHD and so people have looked at adding

       6    post‑transplant immune suppression.

       7    Infection control will probably also help to

       8    control the incidence of GVHD, anything to

       9    reduce in general regimen‑related toxicity

      10    can enhance control of GVHD.

      11              Although host disparity is listed

      12    here, there is less data to actually show

      13    that that is correct.

      14              Now, in some of the work that we

      15    began, actually in the late '80s included

      16    looking at using a fairly broad conditioning

      17    regimen using TBI as the base and then adding

      18    multiple anti‑toxic drugs or antineoplastic
      19    drugs that were commonly used in

      20    transplantation.  Our intent was to both be

      21    immunoblative as well as to try to help

      22    respond to the very refractory leukemia that

                                                            75

       1    we often see in the patients that have

       2    undergone these types of transplants.

       3              So we used a broad approach but

       4    reduced the dose of the drugs compared to the

       5    usual dose used when a single

       6    chemotherapeutic agent is used in combination

       7    with total body irradiation.

       8              Immediately prior to transplant we

       9    gave large doses of steroids both to decrease

      10    cytotoxic ‑‑ the cytotoxic environment in

      11    which the cells were going to be infused, and

      12    to do the last bit of immunoblation of the

      13    host.

      14              In this trial that was published in

      15    transplantation in 1996, we tried to look at

      16    combining ex vivo with in vivo T‑cell

      17    depletion with the concept that if you did

      18    only partial T‑cell depletion of the merrill
      19    graft and at that time we were studying the

      20    use of T‑10, B‑9 for that purpose which led

      21    to a little less than two log T‑cell

      22    depletion and combined that with an agent

                                                            76

       1    that could be given post‑transplant to do in

       2    vivo T‑cell depletion just as T cells were

       3    starting to proliferate in response to

       4    alloantigens that perhaps that sequential

       5    approach could help to ease the way to

       6    engraftment and control of Graft‑verus‑Host

       7    Disease.

       8              At that time we were studying a CD5

       9    immunotoxin for the treatment of acute GVHD

      10    and this drug was explored in this protocol.

      11              In analyzing this pilot trial we

      12    compared patients in the study group with

      13    patient who had consecutively been

      14    transplanted previous to the trial receiving

      15    only T10B9 depleted grafts and no transplant

      16    in vivo T‑cell depletion.  As you can see,

      17    engraftment was excellent in both of these

      18    two arms.  And although the study group did
      19    have a small number of graft failures, these

      20    were primarily seen in children how had

      21    metabolic disorders and they represent a more

      22    difficult group of patients in which to

                                                            77

       1    achieve engraftment.

       2              What we were pleased with was this

       3    really quite remarkable reduction in the

       4    incidence of grade II to IV Graft‑verus‑Host

       5    Disease which occurred actually in all

       6    patients eventually in the previous control

       7    group, the historical control group, and was

       8    reduced to approximately 40 percent in

       9    patients who are received now ex vivo and in

      10    vivo T‑cell depletion.

      11              This also ‑‑

      12              DR. VOSE:  Jean, I'm sorry, could I

      13    interrupt you for a second?  What are the

      14    numbers of patients in those?

      15              DR. HENSLEE‑DOWNEY:  In the study

      16    group?

      17              DR. VOSE:  In the study group,

      18    yeah.
      19              DR. HENSLEE‑DOWNEY:  There were 40

      20    patients and in the historical control there

      21    were 17 patients.

      22              DR. VOSE:  Thank you.

                                                            78

       1              DR. HENSLEE‑DOWNEY:  This did

       2    translate into a trend to improve survival.

       3    And it probably also represented one of the

       4    first trials to demonstrate survival out to

       5    ten years and now beyond for these patients.

       6              We subsequently continue to explore

       7    this approach and we reported in bone marrow

       8    transplant in 1996 a comparison in patients

       9    with acute lymphoblastic leukemia who were

      10    transplanted with a matched sibling donor in

      11    the same period of time that we were

      12    conducting ongoing trials using

      13    haploidentical donors.

      14              These patients had fairly advanced

      15    disease and certainly proportionately the

      16    patients receiving a family donor transplant

      17    were more often in frank relapse at time of

      18    the transplant.  The age groups looked very
      19    similar in these two groups and at the time

      20    of reporting this data, the median follow up

      21    was 6.7 years.

      22              There was no significant difference

                                                            79

       1    in the engraftment between the patients

       2    receiving a matched sibling donor or a

       3    haploidentical donor.  However, there were

       4    graft failures.  And also of interest there

       5    was absolutely no difference in the

       6    likelihood of patients developing very mild

       7    grade 0 to II Graft‑ verus‑Host Disease and

       8    more important grade III to IV disease

       9    comparing the matched sibling with the family

      10    donor.

      11              Not expected, but of interest to us

      12    was the fact that patients who received the

      13    family donor transplant had a lower incidence

      14    of extensive chronic Graft‑verus‑Host

      15    Disease.  We felt that that could best be

      16    explained by the fact that all of these

      17    patients then did receive T‑cell depleted

      18    grafts while these patients all received
      19    unmodified grafts.

      20              When we looked at disease‑free

      21    survival and compared matched sibling donors

      22    with family donors, there was no difference

                                                            80

       1    in an outcome.

       2              Our reviewers asked us to then look

       3    at patients who were transplanted in

       4    remission and combined the one antigen

       5    mismatch haplo transplant with the matched

       6    sibling donor and compare that with the two

       7    and three antigen mismatched donor recipient

       8    pair.  And, again, there was no difference in

       9    disease‑free survival.

      10              This then led to another large

      11    series of haploidentical transplants that

      12    were performed at the University of South

      13    Carolina and reported in blood in 1997.  As

      14    we proceeded with this work, we did become

      15    somewhat more courageous and we began to

      16    offer this type of transplant to even older

      17    individuals.  And, as you can see, in this

      18    group we went up to 50 years of age.  But the
      19    median age was 16.

      20              Also of interest is the fact that

      21    this may represent for American studies the

      22    largest proportion of patients who do

                                                            81

       1    represent minority or ethnic groups.  Still,

       2    even the caucasians that are represented in

       3    this study are those individuals who could

       4    not find an unrelated donor.

       5              Again, the patients tended to be

       6    transplanted for very high‑risk disease and

       7    in fact almost a third of ‑‑ three‑fourths of

       8    the patients were in states of vlas‑crisis or

       9    refractory relapse of the underlying disease.

      10              Even when we categorize patients in

      11    what we might consider a low‑risk group, and

      12    because the patient ‑‑

      13              In this protocol we did make some

      14    changes in our previous approach.  We started

      15    out with a somewhat lower dose of total body

      16    irradiation with a total dose of 1332 and

      17    about three‑fourths of the way through this

      18    number is 26, not 46, we increased the dose
      19    to 1500, and I'll explain the reason for that

      20    in a moment.

      21              We continued to use this broad

      22    approach to chemotherapeutic treatment of the

                                                            82

       1    underlying disease in preparation of the

       2    patient for transplant.  We again used T10B9

       3    to prepare the bone marrow graft, but we did

       4    add additional immune suppression

       5    post‑transplant in the form of very low‑dose

       6    cyclosporin maintaining these levels between

       7    100 and 200 which is much lower than what one

       8    would tend to see in patients receiving an

       9    unrelated graft or a matched sibling donor

      10    graft.

      11              We no longer had access to the CD5

      12    immunotoxin for post‑transplant in vivo

      13    T‑cell depletion and we turned to the

      14    pharmacy for a drug that would be available

      15    as well as looked at other experience that

      16    had been published in transplant.  And as you

      17    may know, the University of Minnesota had

      18    also explored the use of a course of ATG
      19    early post‑ transplant as a way to help

      20    control Graft‑verus‑Host Disease with

      21    favorable results.  So we inserted ATG in the

      22    same place during the protocol that we had

                                                            83

       1    previously given patients the immunotoxin.

       2    And these patients always get pre‑meded with

       3    steroids, but after we complete the 12‑day

       4    course of ATG, we then taper the steroid

       5    therapy.

       6              Now, the engraftment in the study

       7    was actually somewhat disappointing.  In the

       8    majority of patients engraftment occurred

       9    fairly early.  This is a thousand cells for

      10    three consecutive ‑‑ a thousand white cell

      11    count for three consecutive days.  And

      12    patients tended to engraft at about 18 to 20

      13    days out.  However, as you can see, to

      14    achieve complete engraftment in the majority

      15    of patients, there was a proportion of

      16    patients, perhaps about 15 percent who

      17    required second transplants.  And I think

      18    that one always has to see that as a failure
      19    particularly since the survival of efforts to

      20    try to overcome graft failure and

      21    particularly known rejection usually is not

      22    successful.

                                                            84

       1              Now, when we examined ‑‑ the reason

       2    we had increased the dose of TBI was because

       3    we did feel that we were having trouble with

       4    engraftment.  And this is another interesting

       5    observation of the importance of host

       6    conditioning.  So that the kinetics of

       7    engraftment are quite clearly improved in

       8    patients who received more intensive

       9    conditioning prior to transplant compared to

      10    TBI.

      11              Also, in this particular study

      12    there was a significant difference in

      13    engraftment if the donor was three antigen

      14    mismatched compared to donors who were less

      15    than three antigen mismatches.  So this

      16    histocompatibility barrier had an important

      17    impact on engraftment in this study.

      18              On the other hand, our control of
      19    graft versus host disease in this study was

      20    excellent with a 16 percent estimate of grade

      21    II to IV disease in all patients successfully

      22    engrafted with the initial transplant.

                                                            85

       1    Within that only 7 percent of the patients

       2    developed severe grade III to IV disease.

       3              Likewise, the incidence of chronic

       4    graft versus host disease in eligible

       5    patients was within what one might see in a

       6    matched sibling donor cohort, although often,

       7    particularly in older patients, the

       8    likelihood of developing extensive GVHD is

       9    even higher in an unmodified matched sibling

      10    donor transplant.

      11              Survival and a univariant analysis

      12    that compared low‑risk patients to high‑risk

      13    patients was significantly different.  This

      14    is classical for all types of transplants,

      15    even autologous transplants or any type of

      16    allogeneic transplant.  Furthermore, in

      17    analyzing this data in a multi‑variant

      18    analysis risk status or disease status at the
      19    time of transplant was the only feature that

      20    altered outcome.

      21              Now, what I want to draw your

      22    attention to is that using techniques that

                                                            86

       1    did help us to achieve engraftment in the

       2    majority of patients and control

       3    Graft‑verus‑Host Disease led to very good

       4    outcome in the first 100 days.  Even in these

       5    high‑risk patients.  So if you think about

       6    100 days then the mortality risk within 100

       7    days was in the 25 percent range.  And what

       8    drops these outcomes primarily becomes

       9    infection and relapse.  As we look now at the

      10    cause of death in patients on the study and

      11    relapse in essence became our most

      12    significant problem.

      13              Now, you have to remember that

      14    three‑fourths of these patients went into

      15    transplants in frank relapse.  So I don't

      16    think that one could perceive this as a

      17    greater risk of relapse.  And I don't think

      18    it would be a correct assumption to say that
      19    the T‑cell depletion contributed to this

      20    relapse rate.  If one looked at a similar

      21    patient population receiving an unmodified

      22    match sibling donor transplant you would see

                                                            87

       1    a similar, and perhaps even higher rate of

       2    relapse.

       3              Graft failure was still significant

       4    in this group of patients and we considered

       5    that a very serious problem that we needed to

       6    address.  In doing all alternative donor

       7    transplants I think we have to concentrate a

       8    great deal on infection and we must monitor

       9    post transplant immune reconstitution.

      10              However, major organ toxicity or

      11    EBV lymphoma was infrequently seen even in

      12    these ‑‑ well, not infrequently seen, because

      13    I would rather seen none.  But, nonetheless,

      14    in very high‑risk patients this would be what

      15    one would expect.

      16              Now, we did make an interesting

      17    observation in this series of patients as we

      18    examined the immuno phenotyping of the
      19    patients post‑transplant and we saw that in

      20    the early six months to a year after

      21    transplant that a large proportion of these

      22    patients had an increased proportion of gama

                                                            88

       1    delta position T‑cells circulating in their

       2    blood which might have been a result of using

       3    T10B9 depletion of the marrow graft since

       4    this actually interacts with the alpha beta

       5    portion of the T‑cell receptor.

       6              The reason this was of interest to

       7    us is the fact that if we looked at the

       8    patients surviving at least 100 days, the

       9    disease free survival was far superior in

      10    patients who did maintain a greater than 10

      11    percent proportion of circulating gamma delta

      12    positive T‑cells compared to those who had a

      13    smaller proportion of gamma delta T‑cells.

      14    And the reason for that is easily shown on

      15    this slide that looked at the difference in

      16    relapse.

      17              So now we are starting to explore

      18    gamma delta cells and particularly trying to
      19    do co‑culture assays with dendritic cells to

      20    see if these particular cells could be

      21    important post transplant immunotherapy.  And

      22    I think that's going to be another very

                                                            89

       1    important part of doing haploidentical

       2    transplant since I think for some time we

       3    will continue to explore patients with more

       4    difficult disease to treat.

       5              DR. SALOMON:  Were there

       6    correlations such as did you have more graft

       7    versus host disease or a higher ‑‑

       8              DR. HENSLEE‑DOWNEY:  No, we did

       9    not.

      10              DR. SALOMON:  ‑‑ host disease in

      11    these two populations?

      12              DR. HENSLEE‑DOWNEY:  No, we did

      13    not.

      14              DR. SALOMON:  So there was no

      15    effect of having circulating gamma delta

      16    T‑cells?

      17              DR. HENSLEE‑DOWNEY:  No.  Not on

      18    GVHD.
      19              DR. SALOMON:  What about the

      20    circulating alpha beta T‑cells in these

      21    patients, do they follow the same track as

      22    the gamma ‑‑ if you had more gamma delta, did

                                                            90

       1    you have more alpha beta?

       2              DR. HENSLEE‑DOWNEY:  I'm not sure

       3    about that.  I would have to recheck that.

       4    Thanks for the question and I'll look into

       5    it.

       6              DR. SALOMON:  Maybe it could just

       7    be artifactual that you had more alpha beta

       8    T‑cells than ‑‑

       9              DR. HENSLEE‑DOWNEY:  I don't think

      10    so.  But I'd have to really look.  Thank you.

      11              So at this juncture in our work we

      12    felt that sequential immunomodulation could

      13    be very effective in helping to control

      14    Graft‑verus‑Host Disease after haploidentical

      15    transplant.  We at this moment felt that it

      16    was very important to achieve consistent

      17    engraftment, as close to 100 percent as

      18    possible and we knew that advance disease
      19    would significantly worsen survival.

      20    However, if we could make these transplants

      21    safer, then this type of donor being very

      22    readily available to patients would make it

                                                            91

       1    so that one would not have to delay

       2    transplant and one could perhaps affect more

       3    cures.

       4              Now, as we turn to our current

       5    trial we certainly wanted to concentrate on

       6    engraftment, but we also wanted to pay

       7    attention to the fact that there might ‑‑

       8    there was an increasing requirement that one

       9    utilized FDA‑approved technologies to perform

      10    stem cell transplantation.  And, therefore,

      11    when we thought about T‑cell depletion, we

      12    felt that we ought to use an FDA‑ approved

      13    agent although it's not approved for T‑cell

      14    depletion it is nonetheless approved for

      15    human use in renal transplant circumstances.

      16    And there was data in the literature that

      17    where OKT3 had been used previously in this

      18    type of transplant and had been largely
      19    abandoned because as an agent by itself it

      20    was not sufficient to control GVHD.  But you

      21    have to remember that our approach is that we

      22    don't look at T‑cell depletion as the only

                                                            92

       1    part of the protocol that controls GVHD.

       2              We also were not happy with the

       3    higher dose of TVI because we did think it

       4    perhaps was more toxic and so we decided to

       5    go back to a lower dose that we had used

       6    previously at 1400 centigrade and we added

       7    ATG to the conditioning regimen.  And

       8    certainly this has been explored a great deal

       9    as Sloan Kettering using ATG both prior and

      10    after transplant to improve engraftment.

      11              Now, I'd like to show you an

      12    analysis that compares then our previous

      13    patients who received T10B9 with an ongoing

      14    series of patients who have received OKT3

      15    depleted grafts.  And let me just point out

      16    again the changes that were made in the

      17    protocol.  We added ATG three doses at 10

      18    milligrams per kilogram during the time that
      19    patients received ARC.  TBI dose was reduced

      20    to 1400.  And now we're using OKT3 depleted

      21    grafts rather than T10B9.  But otherwise we

      22    continue to give the low dose cyclosporin and

                                                            93

       1    post transplant ATG.

       2              Now we have 210 patients which is

       3    probably one of the largest series in a

       4    single center to examine, 75 who received

       5    T10B9 depleted grafts and 143 who were in the

       6    OKT3 arm.  Our age category actually even

       7    reached a bit higher to 54 years of age and

       8    just for your interest, we have subsequent to

       9    this analysis performed transplant in a

      10    58‑year‑old gentleman who has now over six

      11    months post‑transplant and doing well.  So I

      12    think that we are still very cautious about

      13    which older patient we would be willing to

      14    take through this transplant.  It does still

      15    seem feasible for adult patients.

      16              Our diseases were very similar in

      17    these two series of patients.  Unfortunately,

      18    if anything, the disease status worsened as
      19    we go on.  And so that we have a very small

      20    proportion of patients in the OKT3 arm who

      21    could have been classified in any way in a

      22    quasi‑low‑risk category.

                                                            94

       1              The donors, again, just for your

       2    information 30 to 40 percent of donors have

       3    been parents and siblings.  In fact, probably

       4    75 percent of the time a person would find a

       5    sibling who is haploidentical.  Children

       6    became donors for their parents.  And then,

       7    of course, occasionally cousins or aunts,

       8    uncles, even a grandparent became a donor.

       9              Now, when we retrospectively looked

      10    at the graft results in preparing these

      11    transplants we might immediately say that we

      12    had made a mistake in going from T10B9 to

      13    OKT3 because in fact there was a significant

      14    decline in the number of nucleated cells per

      15    recipient kilogram weight given in this

      16    series of patients.  We didn't actually have

      17    enough patients in the T10B9 group enumerated

      18    for CD34 to make a fair comparison.  But as
      19    you can see, OKT3 was actually a more

      20    effective T‑cell depleting agent leading to

      21    about a two and half log T‑cell depletion so

      22    that we reduce the number of T‑cells

                                                            95

       1    administered to the patients.

       2              But ‑‑ and one wouldn't have

       3    expected that ‑‑ engraftment was fixed.  And

       4    in this series of patients we have actually

       5    experienced a 99 percent successful

       6    engraftment rate, and as you can see, these

       7    patients reach 1,000 white cells for three

       8    consecutive days at about 15, 16, 17 days

       9    post transplant.

      10              Now, I don't think that the reason

      11    for this is the OKT3.  I think the reason for

      12    it is because ATG added substantially to host

      13    conditioning particularly when one thinks

      14    about what we just learned about the grafts

      15    between these two approaches.

      16              Now, if we just look at the OKT3

      17    group and we consider engraftment and the

      18    kinetics of engraftment based on the
      19    nucleated cell dose and we split at the

      20    median and look at those patients above the

      21    median or below the median, as you can see,

      22    the nucleated cell dose at least in this

                                                            96

       1    protocol had no effects on engraftment nor

       2    did the CD34 dose.  But this is what we are

       3    particularly excited about, and that is that

       4    the histoincompatibility of the donor or the

       5    mismatch, the three antigen mismatch in the

       6    donor also had no effect on engraftment for

       7    the first time in our hands.

       8              Now, if we look at the entire 210

       9    patients and look at grade II to IV GVHD it

      10    remained quite low with no statistically

      11    significant difference in engraftment even

      12    though there was a slight trend to more

      13    disease in the OKT3 group.

      14              Grade III to IV disease was

      15    identical in the II series.  And GVHD

      16    mismatch in the patient had no effect on the

      17    likelihood of patients developing grade II to

      18    IV GVHD.
      19              Chronic graft versus host disease

      20    limited and extensive was very similar to

      21    what we had seen in the first series now

      22    extended out to both series.

                                                            97

       1              And outcome with regard to relapse

       2    and survival did not change significantly and

       3    perhaps that's quite a disappointment to us

       4    as we finally overcame those engraftment

       5    problems.  But I think the reason for that is

       6    that as long as we continue to primarily

       7    transplant high‑risk patients with very

       8    refractory disease we are going to continue

       9    to deal with this high relapse rate that has

      10    a marked effect on two‑year survival

      11    estimates.

      12              DR. KURTZBERG:  Is that a ‑‑

      13    survival or overall survival?

      14              DR. HENSLEE‑DOWNEY:  That was

      15    survival.

      16              DR. KURTZBERG:  Overall ‑‑

      17              DR. HENSLEE‑DOWNEY:  Event

      18    pre‑survival is very similar.
      19              Now, just in closing, I had

      20    recently, for the purpose of a textbook,

      21    tried to pull together a number of published

      22    results looking at all alternative donors.

                                                            98

       1    And I used for the matched sibling donor

       2    cohort, actually Slidlow's paper, so this

       3    represents IBMTR data, and tried to think

       4    about were the problems in doing alternative

       5    donor transplants similar across the

       6    different types of alternative donors?  And I

       7    think several things might be draw just by

       8    this casual look at published results.  And,

       9    of course, there are many more results since

      10    this was done, and I'll point out a few of

      11    the things that I've missed.

      12              But with regards to engraftment,

      13    then I think depending on what techniques are

      14    used, engraftment problems can be expected in

      15    both haploidentical transplant and

      16    unrelated‑donor transplant.  Engraftment

      17    problems have perhaps been a bigger issue in

      18    cord blood transplants.  Although new
      19    techniques maybe helping to improve that.

      20    Whether that has done it for all ages yet,

      21    I'll leave to Joanne to discuss.

      22              With regards to acute

                                                            99

       1    Graft‑verus‑Host Disease, again, perhaps the

       2    highest GVHD rates have been published

       3    actually in unrelated, mismatched ‑‑

       4    unrelated transplants and lower ‑‑ generally

       5    lower acute GVHD rates been published in cord

       6    bloods.  However, with highly mismatched

       7    unrelated cord bloods, it's certainly true

       8    that fatal GVHD can occur and is still an

       9    issue.

      10              On the other hand with regards to

      11    chronic Graft‑verus‑Host Disease this is

      12    where I think that cord bloods sort of stand

      13    out, that they truly have across the board

      14    shown less chronic Graft‑verus‑Host Disease.

      15    But when we look a leukemia‑free survival and

      16    what we might consider somewhat low‑risk

      17    patients versus high‑risk patients, then the

      18    differences aren't quite as obvious.
      19              Now, you know, one study that is

      20    obviously not here with regard to unrelateds

      21    is the New England Journal Paper by Hanson

      22    from Seattle where he carefully selected

                                                            100

       1    patients both for molecular HLA typing and

       2    very, very early disease in CML and produced

       3    better results.  But I think always the

       4    disease status, the patient's condition is

       5    going to drive those outcomes more than

       6    anything else.

       7              But I think the reason that it is

       8    so important for us to develop well‑analyzed

       9    studies in haploidentical transplant or in

      10    any alternative donor transplant is because

      11    eventually we may get to the position where

      12    we can start to ask the question, are certain

      13    patients benefitted more by one type of donor

      14    versus another type of donor, and

      15    particularly when should you not wait with a

      16    patient as you seek one donor versus another

      17    donor and turn attention to other available

      18    donors for that individual patient.  And
      19    perhaps some day that we'll ‑‑ once we

      20    establish techniques that we can some

      21    confidence in, we can perhaps do randomized

      22    trial in particular diseases where we think

                                                            101

       1    that alternative donors should be used for

       2    transplantation.  But in the meantime, I

       3    think all alternative donors should be

       4    considered for patients where it is

       5    considered the treatment of choice and that

       6    we should extensively type family members, we

       7    should obtain molecular typing on patients

       8    and donors as quickly as possible to

       9    facilitate search ‑‑ the search process.  But

      10    certainly we need to develop the transplant

      11    option with a consideration to time and cost.

      12              Now, there are still some patients

      13    that would not go down this avenue and I

      14    think we still need to do a lot of

      15    exploration and autologous transplantation

      16    because there is less toxicity there.  And

      17    some people would add in this group, perhaps

      18    CML as they're trying to see if that
      19    technology can be used effectively for that

      20    disease.

      21              But just in finally closing, there

      22    are very compelling reasons to pursue and

                                                            102

       1    study haploidentical transplant.  And I would

       2    just like to review some of those very

       3    quickly.

       4              Probably the lead compelling reason

       5    is donor access.  These donors are

       6    immediately available.  I think I see too

       7    many posters where the child is being held by

       8    the donor who is right now available to them

       9    while they search for a donor that may never

      10    be available to them.  There are no racial or

      11    ethnic restrictions when one uses a family

      12    donor.  Many donors are often available and

      13    so one can often select amongst those donors

      14    and consider other issues that may change

      15    outcome such as sex, age, parity, or

      16    infection concerns.  Also these donors can be

      17    very carefully evaluated.

      18              In addition to that, you have
      19    access to that donor at any point in time.

      20    And as we do develop the technology that we

      21    can use donor cells effectively for

      22    immunotherapy, whether it's against the

                                                            103

       1    disease or infections, then this type of

       2    donor becomes maybe even more efficient.

       3              There is a lot of cost efficiency

       4    in using family donors.  There is less HLA

       5    typing, the graft acquisition cost is very

       6    similar to the use of a matched‑sibling donor

       7    and there are not registry or banking

       8    expenses whatsoever.

       9              In addition there is some

      10    efficiency in being able to obtain the graft

      11    and to prepare the graft in whatever way may

      12    make the transplant more successful.  So you

      13    can, since these grafts are obtained within

      14    the center doing the transplant, you can

      15    control cell volumes and you can use fresh

      16    cells and manipulate those cells in a variety

      17    of different ways that might enhance outcome.

      18              So I'm going to close there.  Thank
      19    you.

      20              DR. VOSE:  Thank you.  Any other

      21    questions or comments for Dr. Henslee‑Downey

      22    on that information?

                                                            104

       1              Well, why don't we go ahead and

       2    move on to Dr. O'Reilly from Memorial Sloan

       3    Kettering and then we'll discuss all the

       4    issues.

       5              DR. O'REILLY:  I'm very pleased to

       6    be here to talk to you.  I thought what I

       7    would do specifically is also review our

       8    experience with T‑cell depleted grafts in the

       9    context of a haplotype disparate donor.

      10    Since we introduced this concept at least in

      11    man back in 1980 with the first transplants

      12    for immune deficiencies and children with

      13    leukemia.  And what I would like to do is

      14    initially update you on the results of HLA

      15    haplotype disparate marrow transplants

      16    administered from parents to children

      17    affected with different forms of severe

      18    combined immune deficiency because I think
      19    these have a lot of continuing lessons in

      20    terms of what ultimately can be achieved

      21    using an haploidentical donor.  And then

      22    we'll briefly look at the issues of

                                                            105

       1    limitations of grafts in the context of the

       2    leukemics as well as what steps have now

       3    recently been achieved.

       4              Many of the points I'm going to be

       5    raising here are going to be reiterations of

       6    what Jean has already told you.  Because I

       7    think several of the issues that were raised

       8    in the initial overview really are now less

       9    problems and we are now introducing other

      10    alternative issues and are actually looking

      11    at new objectives in terms of

      12    transplantation.

      13              So overall now this is looking at a

      14    series of different approaches to T‑cell

      15    depletion.  And what we have done at our

      16    institution was to use limiting dilution

      17    analysis to actually look for clonable

      18    T‑cells in marrow grafts.  And this slide
      19    demonstrates a series of studies that were

      20    initiated at our shop in which marrow ‑‑

      21    single marrow aloquats were obtained and then

      22    were separated by a variety of different

                                                            106

       1    techniques utilized at that particular time.

       2    And suffice it to say that with the lectin,

       3    this is a soybean agglutinin and E‑rosette

       4    depletion.  We used the E‑rosette because CD2

       5    is constituitively expressed at high levels

       6    on T‑ cells and has been a regularly usable

       7    marker for removal of T‑lymphocytes.

       8              The lectin separation removes about

       9    one and a half logs of T‑cells.  It also

      10    removes most of the mature cells in the

      11    marrow such as the B cells, monocytes and

      12    neutrophils, and when you do the E‑ rosette

      13    you get an additional ‑‑ usually one and a

      14    half to two logs ‑‑ so normally it's about

      15    2.8 and it can be in excess of three logs in

      16    repeated studies now.

      17              Multiple E‑rosette depletions can

      18    achieve a maximum of two log depletion.
      19    Different monochromal antibodies have been

      20    used, anti‑CD3, anti‑CD8, with rapid

      21    complement of those have usually yielded no

      22    more than a two log depletion.  Campath is

                                                            107

       1    the closest to where we're at in comparative

       2    trials with about two and a half logs.  And

       3    then if we use lectin followed by ‑‑ of

       4    magnetic separation we could get into three

       5    logs on a regular basis.

       6              An important point that is

       7    comparable in terms of our approach and the

       8    campath approach is that both of these remove

       9    most of the mature cells in the bone marrow,

      10    not only the T‑cells, but also the B‑cells

      11    and mononuclear cells, macrophages as well.

      12              Now, I used to think that in fact

      13    most of what we saw in terms of

      14    Graft‑verus‑Host Disease reflected the

      15    quantitative alterations in the graft.

      16    Unfortunately, I can no longer say that.

      17    Because when we have now looked at CD‑34

      18    depleted marrow, we can say that in fact we
      19    are moving T‑cells to about three logs and

      20    yet the issue of graft versus host disease

      21    has once again come up and made its nasty

      22    head known.

                                                            108

       1              So, without further adieu then, I

       2    would like to talk about the patients with ‑‑

       3    am I going to wrong way?

       4              AUDIENCE:  I think so.

       5              DR. O'REILLY:  The first I would

       6    like to do is to review now 118 patients who

       7    have received transplants from haplotype

       8    disparate donors for the treatment of severe

       9    combined immune deficiency.  This is an

      10    update as of this week.  Looking at

      11    recipients that have been transplanted at

      12    Memorial Sloan Kettering Cancer Center which

      13    is half the series, and the second is using

      14    the identical technique of lectin separation

      15    to E‑rosette depletion at Ülm University

      16    under Wilhelm Frederick who was a former

      17    fellow of ours.  And, in fact, in all aspects

      18    of the trial, the studies have been done in
      19    the same way so we can really look at this

      20    relatively well.

      21              In this particular group where we

      22    have all the absolute clear data on this,

                                                            109

       1    there are 67 where you have an allelic ‑‑

       2    three alleles unique to the donor which would

       3    be for rejection, but in SKD we don't usually

       4    talk about that so much, let's focus on GVH.

       5              Sixty‑three of the patients were

       6    three allele disparate, 41 were two alleles

       7    and 10 of these individuals were allele.

       8    This is not the whole series, there are a

       9    couple of other patients where we're still

      10    going to be absolutely sure about the level

      11    of genetic disparity before we make the

      12    designation.

      13              There's nothing quite so bad as

      14    that sound.

      15              You need a nickel.

      16              I think the obvious point here is

      17    the fact that in the patients with severe

      18    combined immune deficiency you are in a
      19    circumstance where you can use a parental

      20    donor immediately.  There's no waiting

      21    whatsoever.  And what I'm going to be talking

      22    now about really can also now be extended

                                                            110

       1    even to the inter‑uterine transplants where

       2    again T‑depleted grafts are now being

       3    explored for inter‑uterine correction of

       4    severe combined immunal reaction disease.

       5              That was the second worst.

       6              DR. VOSE:  Maybe the first worst.

       7              DR. KURTZBERG:  Now, you have to

       8    shift gears.  This picture will help you

       9    because I'm going to talk about how to use

      10    placental blood which is the baby's blood

      11    left over in the placenta after the baby is

      12    born and which is nature's example of

      13    mobilization to substitute for bone marrow

      14    derived stem cells in unrelated

      15    transplantation.

      16              Over the last several years as

      17    we've been doing this, we've learned some

      18    things about these cells.  One is that these
      19    cells are mobilized throughout pregnancy in

      20    the placenta.  And they're in the placental

      21    blood regardless of the route of delivery

      22    when you collect them after the baby is born.

                                                            111

       1    And, in fact, if there was a way to do it,

       2    you could collect them in utero as well.

       3              Babies who have had their blood

       4    tested for HN compatibility or PUBS for other

       5    reasons even at, you know, 17 weeks, 28

       6    weeks, et cetera have mobilized cells there.

       7    And so therefore, it's an effective labor and

       8    these cells can be collected from placentas

       9    delivered after vaginal or C‑section

      10    deliveries.

      11              In the public banking world,

      12    meaning banks like the bank at the New York

      13    Blood Center and the other banks funded now

      14    by the National Heart, Lung, and Blood

      15    Institute, the decision has been made to

      16    collect from the delivered placenta.  You

      17    really could collect from the placenta before

      18    the third stage of labor after the baby is
      19    delivered, but before the placenta comes out.

      20    But because of really a preference not to

      21    interfere with the care of the mom and the

      22    baby, and also not to have the obstetrical

                                                            112

       1    team be responsible for the collection and

       2    also to preserve privacy and confidentiality

       3    for an unrelated donor.  All of these banks

       4    are collecting from the placenta which is

       5    delivered, taken into another room and then

       6    harvested.

       7              I'll show you a few pictures of how

       8    this is done, partially because of the issue

       9    of a product.  There are a number of

      10    instances now where either for directed

      11    donation or as part of some other public

      12    banking efforts the obstetricians are being

      13    asked to collect and this is not a hard thing

      14    to do, but it is a hard thing to standardize.

      15    And I'll just show you what's going on with

      16    the banks currently that are in HLBI funded.

      17              The placenta is placed, fetal‑side

      18    down in a chuck which is on a stand which is
      19    just a plexiglass stand and then the cord is

      20    brought down through a hole in the chuck and

      21    the platform that the chuck is on.  And you

      22    can see the vein is the tortuous dark vessel

                                                            113

       1    there.  The vein is cleaned with alcohol and

       2    betadine and then punctured with an 18‑gauge

       3    needle that's attached to a standard blood

       4    collection bag that goes down to a bag that

       5    has CPD anticoagulant in it.  And the bag is

       6    placed on a rotating scale so that the

       7    anticoagulant can mix with the blood.  And

       8    also so you can tell when blood is flowing

       9    because you can see the grams rising as blood

      10    comes into the bag.

      11              Usually a collection takes about

      12    ten minutes and I don't know of anyone who

      13    has figured out a way to get more blood than

      14    simply using gravity.  Methods that people

      15    have thought about to squeeze the placenta or

      16    vacuum extract the placenta or perfuse the

      17    placenta are not better and bring up risk of

      18    contaminating maternal cells in the unit
      19    which would be bad for the recipient of the

      20    transplant.

      21              At the beginning of the days when

      22    Hal Broxmeyer wrote in the 1980s about

                                                            114

       1    comparing progenitor cells derived from cord

       2    blood and from bone marrow he felt that any

       3    manipulation of cord blood would lose

       4    progenitors.  And so for the first several

       5    years of banking for related donors there was

       6    no volume reduction and nothing done to

       7    manipulate the unit.  We now know that volume

       8    reduction is possible and along with the

       9    volume reduction red cell depletion can be

      10    accomplished with a hetastarch sedimentation

      11    and then cryopreservation can be done by

      12    standard methodology and 10 part‑time DNA.

      13    So a couple of the banks now through the

      14    NHLBI contractor using this freezer which can

      15    store about 3600 units and it's in 25 mil

      16    bags that are compartmentalized so that later

      17    if the need for ex vivo expansion, gene

      18    manipulation or T‑cell depletion, we don't
      19    really know, but it gives you two ways to

      20    access the unit, a 20 percent portion and an

      21    80 percent portion.

      22              This is a control‑rate freezing arm

                                                            115

       1    which can freeze now in 11 minutes one unit.

       2    And since everything is bar coded you don't

       3    have to go stick your head down in this

       4    freezer to find one of 3600, you just click

       5    on a bar code and the robotic arm does it for

       6    you which is quite nice.

       7              In the current banks the informed

       8    consent process for the donor mom begins with

       9    her first visit to the OB group and she just

      10    receives literature in the packet of stuff

      11    that she gets from them.  We also give talks

      12    at lamaze classes and have posters and videos

      13    in strategically located places.  At 36 weeks

      14    if the mom has expressed interest and she's

      15    sometimes asked again by the OB nursing staff

      16    in the clinic, she can then meet with a

      17    collection nurse who works for the bank, not

      18    for the OB group, and the consenting process
      19    is explained to her.  If she gives her

      20    consent, a detailed medical history is taken

      21    and plans are made for collection when she

      22    delivers.

                                                            116

       1              This process takes about 90 minutes

       2    in our hands, so it's not a short session.

       3    Mom comes into labor and delivery labeled as

       4    a cord blood donor and when the placenta is

       5    delivered it's handed off to the team and

       6    then the team goes back to the mom a day or

       7    so later and says, well, are you sure it's

       8    okay to keep the cord blood.

       9              Mom is also given out‑clause card

      10    that says ‑‑ it's addressed to us, it has a

      11    stamp on it and it says, "I change my mind",

      12    and she doesn't have to say why.

      13              And that's similar to what the Red

      14    Cross does in terms of people maybe not

      15    wanting to disclose some high‑risk behaviors

      16    et cetera.  But then later are feeling like

      17    it would be a better idea not to keep the

      18    unit.
      19              The elements of the informed

      20    consent which is a seven‑page document are

      21    listed here.  One is that this is a voluntary

      22    donation, that there's no guarantee that the

                                                            117

       1    unit, if collected, will be there in the bank

       2    for that family.  And we so not notify

       3    families if the unit is used for an unrelated

       4    donor.

       5              We also know that there are reasons

       6    why the unit may be deemed unbankable either

       7    because of infectious disease serologies or

       8    some problem with processing, et cetera, so

       9    that we don't guarantee that the unit will

      10    there even though the moms agreed to be a

      11    donor.

      12              Mom has to agree to give a sample

      13    of her blood which is used for infectious

      14    disease serologies and she has to agree to

      15    have feedback if those tests are positive.

      16    If mom says no she doesn't want to know, then

      17    she's excluded as a donor.  So that's also

      18    considered a high risk behavior.
      19              Mom's chart and the baby's charts

      20    are reviewed around the time of delivery.

      21    The mom's OB chart is also reviewed.  And in

      22    each bank there's a subsetted feasibility

                                                            118

       1    pilot for look forward to see if it makes

       2    sense either economically or in terms of the

       3    workload to look at these babies later over

       4    the first couple of years of life to see if

       5    they develop a disease that would be

       6    transmittable and expressed in the stem cells

       7    from the cord blood that would be relevant to

       8    the recipient.

       9              In our program we're doing that

      10    with chart reviews at two months, six months,

      11    and two years post‑ transplant.

      12              The consent form also specifically

      13    states that everything is confidential, that

      14    the unit and all the testing is identified by

      15    a bar code label, not by name and demographic

      16    information.  There's only one piece of paper

      17    which is locked up linking the mom's

      18    demographics to the bar code that's used for
      19    all the labeling of the unit.

      20              There also is a clause that says if

      21    the mom ‑‑ or the family wants to remove the

      22    unit and transfer to a private bank at a

                                                            119

       1    later time that they can do that.

       2              I think the issue of this being a

       3    product that can be regulated is an important

       4    one and I'm not against it at all, but I

       5    don't think that all the things we know how

       6    to do are enough to guarantee a successful

       7    transplant.  I think really when you look

       8    back on it, you think you had a good product

       9    if you have a successful transplant.  And, of

      10    course, there are many other things that can

      11    lead into that.  But these are the things we

      12    are doing to try to guarantee a good

      13    product ‑‑ is cultured for sterility and in

      14    the public banking system, if units are

      15    positive for bacterial cultures they are not

      16    maintained in the bank.  And in the private

      17    donation setting we have had units

      18    contaminated with vaginal flow bacteria
      19    transplanted without incident ‑‑ have the

      20    opportunity to exclude anything that might be

      21    of a theoretical risk.

      22              We are counting nucleated cells,

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       1    mononuclear cells, progenitor cells, CFUGMs,

       2    and CD34 cells.  And I'll show you some data

       3    that makes ‑‑ that will make this look

       4    important, but I don't think we have really

       5    all the knowledge we need to know what the

       6    best thing to measure is yet.  Obviously we

       7    need to measure blood type, HLA type which is

       8    done by molecular methods, but at a serologic

       9    level for class one, and at a higher

      10    resolution level for class two just DR beta

      11    one.

      12              In each state hemoglobin

      13    electrophoresis is done on the babies as part

      14    of neonatal screening programs so those

      15    results are obtained four units that were

      16    banked to exclude hemoglobin opathaties, the

      17    viral serologies are done on the mom, again,

      18    because IGG crosses the placenta and
      19    measuring and the babies blood really doesn't

      20    give you any new information.  The detection

      21    of CMV which if viremia was present it would

      22    obviously be of importance to the transplant

                                                            121

       1    and the transplant recipient as a little bit

       2    harder.  If the mom is IGG positive, it does

       3    not mean there is virus in the blood.

       4              At the New York Blood Center they

       5    are culturing the infants saliva and have, I

       6    think, a four per thousand positivity rate.

       7    For the public banks right now we've decided

       8    to look at maternal IGM which does identify

       9    all the virus positive babies, but also

      10    excludes a series of moms who had recent CNV

      11    but are not viremic.  But it was cheaper and

      12    less invasive.  And then a very detailed

      13    family history is taken looking for

      14    unexplained early deaths in the family, a

      15    series of young adults getting gall bladder

      16    surgery or splenectomies suggesting hemolytic

      17    anemias that might have been undiagnosed in

      18    looking for diseases that would be genetic,
      19    and not easily testable.

      20              Another thing to consider is

      21    contamination with maternal cells and this is

      22    just some DNA blots showing how you can tell

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       1    the difference between a mother, a donor and

       2    a patient.  We know there are maternal cells

       3    in the cord blood.  The more sophisticated

       4    the tests become the easier these cells are

       5    to find and they're certainly the one in

       6    100,000 level and the one in 50,000 level.

       7    What we don't know is what's a significant

       8    dose or when that cel inoculant could

       9    contribute to GVHD from the maternal cells in

      10    the recipient of the transplant.

      11              We now have two children who have

      12    had documented engraftment in maternal cells

      13    in the liver post‑transplant.  Both were

      14    picked up about four months post‑transplant

      15    and confirmed on liver biopsy because of

      16    elevated trans‑aminesses.  In both cases

      17    these kids were removed from immuno

      18    suppression and in both cases the maternal
      19    cells went away and the children are well.

      20    One child is out a year now and the other

      21    child is out almost four years.  But we know

      22    that this can occur.

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       1              I'm going to spend some time making

       2    some points with a data set that was put

       3    together with the two largest centers in the

       4    United States doing cord blood transplants

       5    right now and all the units I'll describe

       6    were obtained from the bank at the New York

       7    Blood Center.  At Duke there are about 100

       8    and I think 30 ‑‑ or I'm sorry 120 patients

       9    represented and from Minnesota 33 for a total

      10    now of almost 160.  And in this analysis the

      11    median age of the patients was 7 years, the

      12    oldest being 58 years.  Twenty‑five of these

      13    patients were over 18 and the median age in

      14    that group was 43.  The rest are children.

      15              Median weight, almost 22 kilos with

      16    the largest patient 92 kilos.  Sex

      17    distribution the same as you would expect for

      18    these diseases.  And 50/50 split on CMB
      19    serology in the patients.  No CMB positive

      20    units were transplanted.

      21              Two‑thirds of the patients had

      22    malignant conditions and similar to what Jean

                                                            124

       1    mentioned, these were all high‑risk patients

       2    either in relapse or in late remissions

       3    because of the nature of ‑‑ really phase one

       4    nature of this work and there were a couple

       5    of children with nerve blastoma as well.

       6              And then one‑third of the patients

       7    had non‑ malignant diseases and that included

       8    congenital marrow failure, fanconi, black

       9    fandimon, some in‑born errors in metabolism

      10    including osteopetrosis, crabase, hurlers,

      11    MLD and ALD and leshnihan and then a small

      12    group with immune deficiency which my center

      13    has an unusual culture that's usually a

      14    patient who failed T‑ depleted haplograft

      15    from a parent without any preparative regimen

      16    and then needed ablation to get a second

      17    transplant.

      18              This just gives you some
      19    demographics about the units.  Median volume

      20    was 84 mils and the range was 40 to 214.

      21    Looking at the banks that are collecting

      22    right now and also Dr. Rubenstein's bank, the

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       1    average collection is in a well‑greased

       2    banking system between 80 and 90 mils.  But

       3    you can get units as large as a couple

       4    hundred mils when the placenta is big.

       5              The average cell dose per kilo and

       6    this is nucleated cells dose, and this is the

       7    pre‑cryout count was 3.6 times ten to the 7th

       8    cells per kilo.  That's roughly a lot less

       9    than the traditional bone marrow transplant.

      10    Average CD‑34 cell dose per kilo was 7.6

      11    times ten to the 5th, and you can see there

      12    are wide ranges here.  Average CFUGM dose per

      13    kilo 1.3 times ten to the 4th.  And average

      14    CD‑3 dose as a measure of T‑ cell dosing was

      15    nine times ten to the 6th cells per kilo.  So

      16    although that's lower than what one would

      17    give with bone marrow, that is above the

      18    range where one would be protecting someone
      19    from GVHD.  That is a range where you would

      20    expect to see GVHD.

      21              The patients were prepared either

      22    with TBI and melflan and ATG which was give

                                                            126

       1    day minus three, minus two, and minus one.

       2    At Duke TBI cytoxan and ATG at Minnesota if

       3    they had a malignant condition and if they

       4    were over two years of age.  Patients who

       5    were under two at Duke got busulfan in place

       6    of TBI because of concerns about late

       7    toxicity and patients with genetic conditions

       8    pretty much got busulfan cytoxan ATG unless

       9    they had cardiomyopathy in which case they

      10    got ‑‑ we did a few busulfan melflan patients

      11    just to avoid exposure to cytoxan.

      12              I need to stress that this is

      13    labor‑ intensive, non‑managed care, friendly

      14    transplant.

      15              And it costs money.  The supportive

      16    care is really important.  I come from an

      17    institution where there was a big adult

      18    autologous program that was quote/unquote
      19    "outpatient."  In fact, the patient got chemo

      20    and was discharged on day zero so they could

      21    ceremoniously have their transplant in the

      22    clinic.  But you can't do that with this

                                                            127

       1    transplant.  These patients need much too

       2    much support and they really need a lot of

       3    parental therapy for the first month.  They

       4    all are supported with IVIG which we now

       5    treat for low levels ganciclovir

       6    pre‑transplants if they were CMV positive,

       7    acyclovir post‑transplant.  If they were any

       8    herpes viro serology positive the obvious

       9    transfusions and IV feeding, low‑dose

      10    amphoterous and for fungal prophylaxis, nerve

      11    stem hepafiltration.  At Duke everyone got

      12    G‑CSF from day zero just to standardize care.

      13    And at Minnesota no one got G‑CSF and I'll

      14    show you some data about that later.

      15              And we've now brought about eight

      16    patients through supporting them with

      17    irradiated G‑CSF mobilized granule cites that

      18    we harvested from their parents twice a week
      19    and divided into three doses each if they

      20    came to us infected.  And, again, in this

      21    skid population that's not an uncommon

      22    occurrence and you really can't always clear

                                                            128

       1    the infections.

       2              We've also now gotten three

       3    leukemic patients through with active

       4    aspergillus doing this.

       5              Just to highlight some differences

       6    between Duke and Minnesota.  I mentioned that

       7    at Duke we standardized a G‑CSF approach and

       8    that was as much because I didn't trust our

       9    group not to use it at some point and we

      10    wanted everybody to be as closely matched as

      11    we could.  At Minnesota they did not use it

      12    initially.  TBI was always given at Minnesota

      13    regardless of the disease or the age of the

      14    patient when it was a malignant condition.

      15    And at Duke if the patient was under two,

      16    they did not get TBI.  Of if they had had

      17    prior mediastinal radiation they didn't get

      18    TBI.
      19              At Duke we used high‑dose steroids

      20    for GVH prophylaxis and at Minnesota they

      21    used an intermediate dose.  And I'll come

      22    back to this, but we both used cyclosporin

                                                            129

       1    for nine months post‑transplant.

       2              At Duke we performed more haplo

       3    mismatched grafts than a the Minnesota and

       4    also the adult population came from Duke.

       5              And again I mentioned that in the

       6    leukemic population we used a melphalan‑based

       7    regimen while Minnesota used the

       8    cytoxan‑based regimen.

       9              Donor selection evolved over time

      10    which I think influences some of our results.

      11    At the beginning when we started to do this,

      12    we looked for the best matching unit.  And we

      13    knew we weren't going to get full matches,

      14    but we still took the closest matching unit

      15    regardless of any other considerations.  As

      16    we went along though, and this was really

      17    based on what we knew about bone marrow ‑‑ as

      18    we went along we started to prioritize
      19    allelic matching at DR beta one and we only

      20    do serologic matching for A and B at class

      21    one.

      22              Then as we started to see the data

                                                            130

       1    come out, then I'm going to show you we began

       2    to prioritize cell dose overmatch.  And that

       3    means that we'll insist that we reach a

       4    minimum cell dose and then look for DR beta

       5    one matching and then third look for class

       6    one matching.  And we will pick a larger four

       7    of six over a smaller five of six in order to

       8    meet this criteria.

       9              We don't look at HLAC for the other

      10    DR DPQ proteins or alleles.

      11              By those criteria the patients are

      12    pretty much a group of five of six or four of

      13    six matched grafts.  You can see 10 percent

      14    or six of six, and that's 6 percent or three

      15    of six.  And this is, again, serologic typing

      16    class I and molecular typing of DR beta one.

      17              We all pretty much believed that if

      18    we did molecular typing at class I we would
      19    have obviously a lot more mismatching.

      20              And now I'm going to show you some

      21    outcomes.  We defined engraftment as the

      22    first of three days to reach an ANC of 500.

                                                            131

       1    And graft failure as failure to reach an ANC

       2    of 500 by day 42.  And I already mentioned

       3    matching.

       4              Engraftment.  This looks at

       5    neutrophil engraftment; 87 percent of the

       6    patients engrafted by day 42 with a median

       7    day to ANC of 500 of 25 days.  You can see of

       8    all engrafting patients which was 93 percent

       9    the range was out to 59 days which

      10    functionally we think is really too long.  We

      11    take it if we get it, but that's not really

      12    what we're aiming for.

      13              When we looked at what impacted

      14    engraftment HLA disparity between the donor

      15    and recipient did not impact engraftment.

      16    These are the ‑‑ green is the two antigen and

      17    yellow is the one antigen and, of course,

      18    those are the biggest groups.  But the three
      19    and the zero antigen match did not come out

      20    as statistically different.

      21              G‑CSF in this not randomized, not

      22    controlled, but just as kind of simultaneous

                                                            132

       1    comparison did look like it influenced

       2    engraftment and there was a nine‑day

       3    difference in the median day to ANC of 500

       4    between the Duke Group and the Minnesota

       5    group.  And so without any randomized trial

       6    the Minnesota group has switched over to

       7    using G in everyone.

       8              We were concerned at Duke that if

       9    we withheld TBI because of the fact that

      10    these were mismatched grafts we might see

      11    more graft failure.  And this just shows you

      12    that we didn't ‑‑ this is a univariant

      13    analysis and it's a little bit misleading

      14    because the children in this group overall

      15    are younger, smaller, and got a higher cell

      16    dose.  But at least we could say that there

      17    was no negative effect of not giving TBI to

      18    that group.
      19              DR. ANDERSON:  If you took the

      20    pediatric age group out of that and just ‑‑

      21    what do you see?

      22              DR. KURTZBERG:  The same thing.  We

                                                            133

       1    have had ‑‑ we've done a number of adults.

       2    It's about 11 or 12 true adults over 18 and

       3    then another 15 kids who were between 12 and

       4    18 with bumel or busi and none of them have

       5    had graft failure.  So in fact our adult

       6    group which is led by Nelson Chow would

       7    prefer to leave the TBI out now for other

       8    reasons.  So we can't see any negative

       9    influence of withholding TBI.

      10              And in multi‑variant analysis the

      11    only thing that impacted neutrophil

      12    engraftment was cell dose.  And now this is

      13    shown here measured as CD‑34 cell dose.  I

      14    could show you similar data with mononuclear

      15    cell dose or nucleated cell dose or CFUGM

      16    dose.  And when you do the statistics they

      17    all correlate with each other.  So people

      18    like CD‑34 and I made this slide, but it's
      19    not the only thing that correlates.

      20              A CD‑34 dose less than three times

      21    ten to the 5th cells per kilo which is a log

      22    less than we would give with bone marrow or

                                                            134

       1    peripheral blood progenitor cells is

       2    associated with delayed engraftment and

       3    inferior engraftment over all.  And so that

       4    now when we select units we are deliberately

       5    avoiding getting this low.  In the other

       6    three groups, looking at three to six, seven

       7    to 16 or greater than 16 times ten to 5th per

       8    kilo we couldn't really see any difference in

       9    engraftment.

      10              Likewise for platelet engraftment

      11    the group getting less than three times ten

      12    to the fifth, 34 per kilo had very inferior

      13    platelet engraftment.  In fact, only half

      14    engrafted platelets at all.  So that this is

      15    raising a red flag as a surrogate for cell

      16    dose of where our limitations with this kind

      17    of product may be.

      18              Immune reconstitution, I know this
      19    is a busy slide, and I'm going to explain

      20    more on the next slide, but it just shows you

      21    kind of how many time points we have on each

      22    patient and where this is just PHA responses

                                                            135

       1    of lymphocytes and culture, every three

       2    months for the first year post‑transplant and

       3    then at varying time points after that.  And

       4    you can see that in the first three months

       5    more than half the patients are not having

       6    their lymphocytes proliferate and even the

       7    ones who do have so few lymphocytes that I

       8    don't think it matters.  Between three and

       9    six months about half the patients start to

      10    recover and it isn't until a year that the

      11    patients are consistently at normal ranges.

      12              Now cyclosporin has stopped around

      13    nine months, so that also may influence some

      14    of this recovery.  If you look at other

      15    parameters of immune reconstitution and these

      16    reflect studies done in Rebecca Buckley's lab

      17    at Duke through the pediatric immunology

      18    group, all patients were profoundly
      19    lymphopenic meaning lymphocytes counted less

      20    than 500 for the first six months and less

      21    than 800 until mostly ‑‑ almost out to 12

      22    months.  We can demonstrate normal and K cell

                                                            136

       1    function at three months.  T‑cell

       2    proliferation begins to recover at six months

       3    and is normal in everyone after 12 months.

       4    T‑cell proliferation N numbers increase

       5    between six and nine months and then settle

       6    out to normal ranges after that.  And we

       7    haven't seen any BV lymphomas in our two

       8    groups of patients, although I think there

       9    are one or two in the whole series of ‑‑

      10    collected in about 600 patients now.

      11              CD‑4 counts recover between nine

      12    and 12 months.  That means to over 200.  And

      13    we see a persistence of increased naive

      14    T‑cells, CD‑4 to 5 RA cells even out as long

      15    as three years in patients that we've been

      16    able to follow that long.

      17              Despite that though, there are

      18    normal responses to immunizations after one
      19    year.  And now in 90 kids who are out more

      20    than a year we've only had one case of

      21    pneumococcal sepsis.  Or we have had one case

      22    of pneumococcal sepsis reported to us, but

                                                            137

       1    the other kids are back to normal performance

       2    status, normal activity and not on any kind

       3    of prophylaxis.

       4              Acute Graft‑verus‑Host Disease

       5    moderate to severe grades two to four

       6    occurred in 37 percent of patients and the

       7    subset that were three to four is 14 percent.

       8    That was not influenced by HLA disparity.

       9    And that's also true, this is now a grade

      10    three to four subset for HLA disparity.  But

      11    we couldn't see an effective mismatching on

      12    the incidence of acute GVHD.

      13              And, in fact, in multi‑variant

      14    analysis the only thing that did impact on

      15    incidence of acute GVHD was CD3 dose.  And if

      16    it got to be above 1.6 times ten to the ‑‑

      17    sorry ‑‑ 1.6 times ten to the 7th cells per

      18    kilo, then there was a statistically
      19    significant increase in acute GVHD at the .03

      20    level.

      21              Interestingly and I think

      22    importantly, chronic GVHD has occurred at a

                                                            138

       1    very low rate.  This is held up.  This is a

       2    probability of 11 percent overall.  None of

       3    this has been extensive.  It's all been

       4    either skin rash or some poor weight gain

       5    which corrects with steroids and no one is on

       6    long‑term immunosuppression for chronic GVHD

       7    at this point.

       8              Relapse has a probability of

       9    occurring in 25 percent of patients and to me

      10    given the nature of the high‑risk criteria of

      11    the patients we transplanted, I think we are

      12    seeing a preserved graft versus leukemia

      13    effect, but obviously we need to look at that

      14    more carefully.  We do have one patient now

      15    who had a three of six antigen matching graft

      16    for very refractory CD7 positive immature

      17    leukemia who when it was in relapse at the

      18    time of transplant went into remission post‑
      19    transplant.  Relapse six months

      20    post‑transplant was taken off

      21    immunosuppression and is now a 100 percent

      22    donor again in the marrow and the blood and

                                                            139

       1    has no clinical evidence of leukemia.  So

       2    again, that suggests to me and that's a

       3    highly mismatched graft, but at least in that

       4    setting we did document a GVL effect.

       5              Interestingly and I don't know how

       6    to explain this, the patients getting G‑CSF

       7    have a lower probability of relapse than

       8    those not getting G‑CSF.  Now, you could

       9    argue well, remember I said, Duke gets G and

      10    Minnesota doesn't.  Duke gets melphalan and

      11    Minnesota doesn't.  But we went back and did

      12    those analyses and there was no effect of

      13    melphalan in this.

      14              Minnesota went back and did a small

      15    series of patients where they randomized

      16    between G and no G and also saw the same

      17    result where the G patients were relapsing at

      18    a lower frequency than the non‑G patients.
      19    But I don't know how to explain this.  G

      20    means that they continued out to 100 days on

      21    G‑CSF support and their white count was

      22    maintained at around 20,000.

                                                            140

       1              The overall event free survival of

       2    the whole group is 44 percent at two years.

       3    Things that did or did not impact survival I

       4    will go over now.  These are uni‑varied

       5    analyses and I'll show you multi‑varied at

       6    the end.

       7              HLA did not appear to impact

       8    survival.  The green is the two antigen

       9    mismatches.  The yellow is the one, the three

      10    and the zero on the bottom, again these are

      11    smaller groups and we may not have enough

      12    patients to reach statistical power for these

      13    two groups, but this is the data that we have

      14    so far.

      15              If you looked at whether a single

      16    class one antigen mismatch versus a single

      17    class two antigen mismatched impact survival

      18    the answer was no.  And if we looked at
      19    whether in the two antigen mismatched

      20    patients whether the mismatch was at two

      21    class one or one class one and one class two

      22    impacted survival the answer was also no.

                                                            141

       1    And the survival is the same in the group of

       2    three antigen mismatched patients as it is in

       3    the zero.

       4              I think you need to think about it

       5    for a minute though and realize that these

       6    are not haplo in the sense of Jean's haplos.

       7    These are people where we can pick and choose

       8    which antigen we match and mismatch and so we

       9    can have one class ‑‑ you know, two B‑loca

      10    mismatches and complete matching at ANDR.

      11    Vice versa we can have molecular mismatching

      12    at DR, but serologic mismatching at class

      13    one, it's not going in pairs of ABDR like you

      14    would if you were in the matched or related

      15    setting.

      16              Diagnosis in uni‑varied analysis

      17    did impact survival.  The kids with

      18    non‑malignant conditions had an improved
      19    survival over those with malignant

      20    conditions.

      21              And age impacted survival so that

      22    the group under two has about an 80 percent

                                                            142

       1    event‑free survival and the older groups are

       2    down around 40 percent.  There is not a

       3    difference in the greater than 18 and 2‑ to

       4    17‑year‑old group in our hands.  The kids

       5    under one have a 90 percent event‑free

       6    survival.

       7              But the thing in multi‑variant

       8    analysis that impacted survival was again

       9    cell dose here shown as CD‑ 34 and there was

      10    an 80 percent non‑relapse mortality in the

      11    group getting less than three times ten to

      12    the fifth per kilo.

      13              If you want to look at total

      14    nucleated cells this translated into 1.5

      15    times ten to the seventh total nucleated

      16    cells per kilo.

      17              The early non‑relapse mortality

      18    seems to be related to cell dose.  And in
      19    that group infections were the major reason

      20    for failure.  And it wasn't one kind of

      21    infection.  We had a number of patients,

      22    particularly on the adult side die of grand

                                                            143

       1    negative sepsis.  Some patients die of either

       2    adenovirus or CMV although the CMV deaths are

       3    at about 2 percent and the incidence of CMV

       4    disease is 8 percent overall.

       5              And then some patients dying of

       6    fungal infections and these are all patients

       7    who came with a history of fungal infections

       8    in their past life, leukemic life.  Why might

       9    that be?  One is ‑‑ these are just theories.

      10    One possibility is that we're recapitulating

      11    neonatal neutrophil maturation.  We know that

      12    neonatal neutrophils are not as efficient at

      13    killing as adult neutrophils.  "Adult"

      14    meaning taking an older baby.  And it's

      15    possible that we're seeing that process again

      16    and that could be overcome by cytokine or

      17    maybe by ex vivo expansion.

      18              I'm sure there's delayed immune
      19    reconstitution secondary to the HLA

      20    mismatching, but I'm encouraged by the fact

      21    that after a year there really appears to be

      22    full reconstitution.  And it's a question of

                                                            144

       1    supporting the patients through that early

       2    transplant period so that they can get to

       3    that point.  And that may also relate to

       4    transplantation of more naive T‑cells.

       5              Another thing just looking back at

       6    our own practice was that we found that

       7    comparing the patients who got intermediate

       8    or high‑dose methylpred with cyclosporin for

       9    GVH prophylaxis, there was no difference in

      10    the incidence or severity of acute GVHD.  But

      11    when we looked at the incidence of infection

      12    or non‑relapse mortality, the group getting

      13    the higher dose steroids had twice the

      14    non‑relapse mortality as the group getting

      15    the lower dose steroids.  And we now have cut

      16    back to the lower dose steroids because we

      17    don't need to push this to have an impact on

      18    GVHD.
      19              Another approach we're taking is ex

      20    vivo expansion and we have just finished a

      21    trial of 28 patients getting ex vivo expanded

      22    cells as a supplement on day 12

                                                            145

       1    post‑transplant.  And one of the obstacles to

       2    this study was that all the units that we had

       3    were frozen in one bag.  And so we couldn't

       4    compartmentalize or do any expansion

       5    pre‑transplant.  And so we took the unit on

       6    day zero and actually divided the patients

       7    into two subgroups of the fixed dose of

       8    unmanipulated cells that they received

       9    expanded whatever was remaining in conditions

      10    that were really derived for bone marrow, but

      11    included three ligand pixie and epo.

      12              The expansion was a 12‑day process

      13    and on the 12th day the cells were harvested

      14    and then infused without any other

      15    preparation.  We didn't change anything else

      16    about the kind of care the patients were

      17    receiving.

      18              This just shows you the lab data
      19    about what expanded under these conditions

      20    total cell count expanded about two and a

      21    half to threefold.  CFUGM expanded on average

      22    150 fold.  CD34 ‑‑ negative cells did not

                                                            146

       1    expand at all, 34‑38 positive cells did

       2    expand, but those were really just maturing

       3    myeloid precursors.

       4              And this does really represent a

       5    form of T‑ cell depletion because the T‑cells

       6    go away under these conditions.  There's

       7    hydrocortisone in the media and so that you

       8    take away part of the dose you would have

       9    given in the unmanipulated graft.

      10              We are also looking in the

      11    laboratory at other factors that can enhance

      12    expansion and this just shows you that if we

      13    take placenta and we expose the cells ‑‑ this

      14    is a control in blue, and then placenta in

      15    the well in pink, we can get more expansion

      16    with placenta and we are considering using

      17    irradiated placenta from the actual cord

      18    blood donor as a possible source of cytokine
      19    expansion.  We can get increased expansion

      20    with stem cell factor as well, but that

      21    requires corporate cooperation which is a

      22    bigger obstacle right now than some of the

                                                            147

       1    scientific ones.

       2              This shows you 100‑day survival in

       3    the group getting expanded cells compared to

       4    two groups getting those lower cell doses of

       5    unexpended cells, but no boost.  And these

       6    are historical controls.

       7              The reason I'm showing you survival

       8    is because we don't have any impact at all on

       9    engraftment.  The data on engraftment is the

      10    same for platelets and neutrophils and the

      11    proportion of patients engrafting is exactly

      12    the same.  But the 100‑day event‑free

      13    survival looks different.  And this is a nice

      14    picture, but I can also show you that if you

      15    look at just ‑‑ at cord blood transplant

      16    survival over the past four years, you can

      17    see that we've been increasing our success, I

      18    think, because we've learned how to do this
      19    better or we're selecting units differently.

      20    We have changed our GVH prophylaxis et

      21    cetera.  So when the issue of controls comes

      22    up, this is really important because you know

                                                            148

       1    the company was really happy with the first

       2    graft, and I'm not unhappy with it.  But I

       3    can be sure that it was because of ex vivo

       4    expansion or it was just because we're doing

       5    a lot of things hopefully better as we go

       6    along.

       7              So in summary what do we know about

       8    cord blood transplant right now?  We know

       9    that it increases donor availability, and at

      10    the 4 of 6 level we can find donors for 86

      11    percent of the patients who come to us who

      12    haven't found traditional donors in other

      13    settings taking away the haplorelated donor.

      14              We know that we see less acute and

      15    chronic GVHD than we would expect with mature

      16    adult cells that were better matched from

      17    either bone marrow or stem cells and we

      18    believe that the GVL effect is preserved.
      19    The obstacles we're still seeing are that

      20    there's delayed engraftment and if nothing

      21    else it makes it more expensive which makes

      22    the whole procedure more challenging in the

                                                            149

       1    current reimbursement environment.

       2              There's delayed immune

       3    reconstitution although it does occur and

       4    that leads to increased morbidity and

       5    mortality from early infections.

       6              I want to end by just mentioning a

       7    couple of things.  This little boy has

       8    thalassemia major and had a haplorelated cord

       9    blood from his sister's cord blood 100 days

      10    before this picture was taken.  And he's two

      11    years out now fully engrafted with donor

      12    cells.  And we've done four other children

      13    this way.  And I think the haplorelated cord

      14    blood setting may turn out to be valuable for

      15    kids with hemoglobinopathy, sickle cell ‑‑

      16    and some of the other rare genetic diseases.

      17    And that may be the one place where family

      18    banking or directed donor banking makes
      19    sense.

      20              And also just to say what's the

      21    state of the art in a pediatric transplant

      22    unit that does ‑‑ you know, we do about 90

                                                            150

       1    transplants a year.  I'll illustrate this

       2    kindred of kids from Alabama who all have

       3    fanconi.  They're all cousins and they have

       4    many relatives who are inbred.  This little

       5    boy is two years out from matched sibling

       6    transplant.  He's one year out from a matched

       7    transplant from his HLA identical mom.  She's

       8    three and a half years out from a three of

       9    six unrelated cord blood transplant and she

      10    is a few months out from a five of six

      11    related cord blood transplant from her aunt.

      12    And she had some acute GVH and that's why

      13    she's cushingoid, but she's six months past

      14    this picture and doing well.

      15              And I guess my point here is that I

      16    don't think there's one kind of transplant

      17    that we ought to be doing.  I think there are

      18    going to be settings where we will use a
      19    haplorelative and there will be other

      20    settings where we need to move faster and we

      21    might use cord blood.  There are a lot of

      22    unanswered questions and I think we need to

                                                            151

       1    collect the data in a way that we can

       2    interpret it and then make the best

       3    decisions.  And I'll stop there and see if

       4    people have questions.

       5              DR. VOSE:  Thank you, any questions

       6    or comments for Dr. Kurtzberg?  Please, can

       7    you also identify yourself.

       8              MS. RIM:  Ilana Rim from Genetics

       9    Institute.  I wanted to ask you a question

      10    related to both your presentation and Dr.

      11    Henslee‑Downey's which was clear from the

      12    confluence of them which is that your data

      13    showed a lot of variation with relapse on

      14    G‑CSF and your showed it with gamma delta

      15    cells and I wondered if either of you had

      16    data on the opposite experiment.  Whether you

      17    had looked at gamma delta cells and whether

      18    you had looked at time of engraftment.
      19              DR. HENSLEE‑DOWNEY:  I haven't, no.

      20              DR. KURTZBERG:  We have the data,

      21    but I don't have it analyzed.  We could look

      22    at it.

                                                            152

       1              MS. RIM:  I just wonder if it's a

       2    marker of the same event of early engraftment

       3    that is relevant for relapse?

       4              DR. KURTZBERG:  I will say though

       5    that in our own experience and I didn't have

       6    time to make slides, we've done 47 related

       7    haplo transplants, 17 of which were five of

       8    six and the others were four of six and three

       9    of six mismatches.  And our event‑free

      10    survival in that group for all is 43 percent.

      11    If you subset it out to the patients who were

      12    T‑cell depleted and who were not T‑cell

      13    depleted, the T‑cell depleted group has a

      14    survival of 35 percent and the not T‑cell

      15    depleted group has a survival of 53 percent.

      16    But if you take out the SBA or the soybean

      17    lectin in ER method of T‑ cell depletion and

      18    just look at the T10B9 or we used a chemical
      19    purge with the ‑‑ formycin which is a lesser

      20    purge in terms of logs of T‑cell removal.

      21    Those groups have 53 percent event‑free

      22    survival and are the same as the non‑T

                                                            153

       1    depletive five of six antigen matched group.

       2              And the only reason I share that is

       3    because it's one center that's doing two

       4    different kinds of alternative donors and

       5    realizing pretty much similar results.

       6              DR. O'FALLEN:  You described a very

       7    complicated consenting process, but I don't

       8    think you told us what percent of the mothers

       9    actually consent.

      10              DR. KURTZBERG:  It's about 95.  But

      11    I think I'm in a unique setting.  Not unique,

      12    but it's different than being in the middle

      13    of New York City which is kind of what I'm

      14    comparing it to because of Pablo's

      15    experience.  And we have a community that

      16    gets fairly consistent prenatal care and is

      17    very interested in participating in these

      18    kinds of studies.  And so our biggest refusal
      19    was one intensive care nursery nurse who

      20    decided that she didn't ‑‑ you know, she was

      21    our only obvious refusal in over ‑‑ I think

      22    we've consented about 700 women right now.

                                                            154

       1              DR. PAPADOPOULOS:  Joanne, could

       2    you please clarify your immuno constitution

       3    data?  Do you have a difference in the adults

       4    versus the children?

       5              DR. KURTZBERG:  I don't think so.

       6    And I'm being hesitant because I have more of

       7    the data on the kids.  The data I've seen on

       8    the adults is not different, but they haven't

       9    been as good about getting some of the time

      10    points.  But, no, the adults are lymphopenic

      11    and, you know, they have all the

      12    abnormalities that the kids have for the same

      13    time period and seem ‑‑

      14              DR. PAPADOPOULOS:  But do they

      15    recover at a later time point than the

      16    children?

      17              DR. KURTZBERG:  I don't think so.

      18    But I can't be as clear about the group that
      19    the adults in my group transplanted.  We've

      20    done some adults ourselves, and those adults

      21    I know exactly how they're doing and they're

      22    not different than the kids.  But there's may

                                                            155

       1    15 more that I have incomplete data on.

       2              There is, though ‑‑ there are at

       3    least three adults who had later bacterial

       4    sepsis than we've ever seen in the kids and

       5    this was between nine and 12 months

       6    post‑transplant.  And we haven't seen that in

       7    the kids.  So there may be something

       8    different in the adults that I can't

       9    quantitate for you now.

      10              DR. VOSE:  I think that does bring

      11    up an important point that we need to think

      12    when we're talking about study design is that

      13    you can't directly compare pediatric

      14    populations and adult populations, they may

      15    need to have different study designs.  So I

      16    think that's important when we think about

      17    that later.

      18              Any other questions or comments?
      19              Why don't we try again, Dr.

      20    O'Reilly?

      21              DR. O'REILLY:  I'm hoping that the

      22    slides get through.  What I would like to do

                                                            156

       1    is then discuss haplotype disparate grafts.

       2    I think it's important for the committee to

       3    recognize one thing that is different about

       4    this approach to T‑cell depletion and that is

       5    that the studies I'm talking about at the

       6    present time utilize T‑cell depletion alone.

       7              There is no post‑transplant

       8    prophylaxis against Graft‑verus‑Host Disease

       9    administered in any of these patients.  It's

      10    a critical variable in terms of this.  So

      11    this is what T‑cell depletion can do on its

      12    own.  And this is particularly germane to the

      13    study of the kids with severe combined immune

      14    deficiency.

      15              So I mentioned the fact that the ‑‑

      16    as you see in this particular group over 100

      17    of these 118 individuals are in fact in the

      18    context of two or three antigen disparate
      19    donor recipient pairing with transplants from

      20    the parent to a child.

      21              Now, this is a summary of these

      22    results and I'm going to go over this slide

                                                            157

       1    relatively carefully, but I have a lot of

       2    background data vis‑a‑vis immune

       3    reconstitution should the committee want it.

       4              Of that total patients there are

       5    118 patients of whom five died early of

       6    intercurrent infections and anti‑data to the

       7    transplant.  And remember this is a

       8    consecutive series since the initial

       9    transplant was done in 1980.  So it's every

      10    child with severe combined immune deficiency

      11    who has received a haplotype disparate graft

      12    at these two institutions.

      13              There are 96 of these patients who

      14    achieved durable engraftment.  The issue of

      15    engraftment not being achieved was

      16    principally a focus or an issue that we

      17    encountered early on when we thought that

      18    children with severe combined immune
      19    deficiency that is these are children who do

      20    not have functional T‑cells or B‑ cells would

      21    not be capable of resisting a graft.  And

      22    I'll talk about that in a bit.  But there are

                                                            158

       1    17 who failed to achieve engraftment.  Yet of

       2    these individuals who did engraft 72 achieved

       3    full reconstitution of T‑cell function, 20

       4    were partial at the time we analyzed these

       5    and there are 10 patients who are still early

       6    in recovery of immunologic function of the

       7    T‑cells.  The important point is that of the

       8    42 patients who achieved engraftment of donor

       9    B cells 35 of the 42 are full functional

      10    reconstitutions in terms of B cells, in terms

      11    of production of antibodies in all classes of

      12    immunoglobulins.

      13              In contrast, if we failed to

      14    engraft donor B cells only four of 64

      15    patients have achieved durable engraftment.

      16              Now, remember a large proportion of

      17    this population are recipients of severe ‑‑

      18    of these T‑ depleted transplants without any
      19    sign of reduction whatsoever.  Okay.

      20              So there is no sign of reductions.

      21    In the absence of sign of reductions

      22    routinely we will engraft T‑cells of donor

                                                            159

       1    origin and have full immunologic recovery of

       2    the T‑cell function, but we will not engraft

       3    donor B cells.  If on the other hand you

       4    myeloblate this individuals with even low

       5    doses of busulfan and cyclophosphamide you

       6    consistently engraft the T‑cells and the B

       7    cells of donor you will have either a split

       8    chimeric state in terms of the B cells or

       9    full donor chimerism and in all instances we

      10    see evidence of immunologic recovery.

      11              The other important point to be

      12    raised is that among these 118 patients and

      13    the 96 durably engrafted there are only seven

      14    patients developed any evidence of

      15    Graft‑verus‑Host Disease and as you see this

      16    included six patients with grade two disease.

      17    This is in the absence of any

      18    Graft‑verus‑Host Disease prophylaxis.  Each
      19    of these instances resolved with therapy.

      20              Of the patients who died and there

      21    were 40, the causes of death were principally

      22    infection.  Most of these antecedent to the

                                                            160

       1    transplant.  There were two patients who died

       2    of Graft‑verus‑Host Disease that had maternal

       3    fetal Graft‑verus‑Host Disease at the time

       4    they were initially admitted.  That is, they

       5    received an inter‑uterine infusion of cells

       6    they came in chimeric with maternal cells

       7    with overt Graft‑verus‑ Host Disease and went

       8    on to die of that complication.  But the

       9    overall long‑term disease‑free survival, the

      10    78 out of 118 patients or 66 percent.

      11              If you now ask the question how

      12    does a T‑cell depletion depleted graft

      13    actually grow up?  This is a transplant that

      14    is conferring to these individuals doses of

      15    T‑cells ranging between two and eight times

      16    ten to the fourth T‑cells per kilogram body

      17    weight.  What we observed in these patients

      18    long‑term is that these populations of
      19    T‑cells that grow up within the child

      20    actually grow from early progenitors.  We

      21    have had autopsies on those patients who have

      22    died and can demonstrate that the thymus

                                                            161

       1    wasn't brinell is now basically filled in

       2    with T‑cells.  These are of donor type

       3    T‑cells and you will see development of

       4    hassles corpuscles and you can also

       5    demonstrate as shown here in the study that

       6    was done by Neal Phomenberg some time ago if

       7    you compare the response of the mother who is

       8    haplotype disparate with the child, if this

       9    mother is challenged with paternal cells and

      10    this is the sensitizing determinants, you can

      11    see that mom's T‑ cells are clearly capable

      12    of killing the father at 68 percent

      13    cytotoxicity and killing the cells of the

      14    child.  This is a B cell line at 69 percent

      15    cytotoxicity and also kills the DR‑3

      16    homozygous population that bears the DR‑3

      17    conferred by the father at 69 percent.

      18              If you now look at this patient,
      19    this patient is now ‑‑ at this time he was

      20    about 18 months post‑ transplant, was full

      21    engrafted.  All of his T‑cells were of

      22    maternal origin and these maternal T‑cells

                                                            162

       1    are now challenged with the father in vitro

       2    and they are asked what did they do.  And

       3    they can still kill the father cells by

       4    virtue of the unshared haplotype but they

       5    have no reactivity whatsoever against the

       6    patient or against the homozygous line.

       7              When we have done limiting dilution

       8    analyses or when we have done mixing

       9    experiments to determine whether this is

      10    based on the suppressor cell, what we can say

      11    is that there is no effect of the mixing of

      12    the patients.  That is maternal T‑cells with

      13    the mom's own cells.  These engrafted

      14    populations exert no inhibitory effect on the

      15    cytotoxicity of the mother's cells either in

      16    the time of sensitization or in the time of

      17    their effector function.

      18              Thus, from what we are able to see
      19    in these patients who received these lectin

      20    separated T‑depleted grafts, the primary

      21    basis of the tolerance observed is actually a

      22    deletion of T‑cells capable of reacting

                                                            163

       1    against host.  And in further studies that

       2    we've now done looking at viruses ‑‑ and I

       3    don't have time to show this ‑‑ we can in

       4    fact show that the T‑cells that emerge that

       5    are of donor type have the capacity to engage

       6    virus infected cells in the context of the

       7    HLA that is unique to the host.  So they

       8    learn and they are capable of recognizing

       9    influenza, epstein bar virus, and other

      10    antigens in the context of both helper‑based

      11    T‑cell responses documented by proliferation

      12    as well as cytotoxic responses looking at

      13    CD‑8 reacted populations of cells.

      14              The long‑term disease‑free survival

      15    for this particular group on all patients is

      16    64 percent, but I think it's important also

      17    to recognize the fact that this reflects in

      18    part the early series from 1980 to
      19    approximately 1986 when we were doing a

      20    prospective study to try and analyze which

      21    patients would or would not engraft.  And

      22    suffice it to say that two coeruleus were

                                                            164

       1    associated with non‑engraftment of these T‑

       2    depleted transplants.  One was the presence

       3    of AD‑8 deficiency which precluded

       4    engraftment in a significant proportion.  But

       5    the major correlate in fact was the presence

       6    of natural killer cells.  Almost all of these

       7    patients who were NK deficient engrafted.

       8    The only ones who engrafted who still had NK

       9    activity are intriguingly individuals who

      10    presented with disseminated BCG ossis.

      11              And certain members of this team

      12    will be smiling because in fact when

      13    Gusipuovich initially described the phenomena

      14    of what is called F‑1 hybrid resistance which

      15    has been shown to be an NK mediated

      16    resistance against hematopoietic cells, the

      17    one way that you could overcome that

      18    resistance was to give BCG to the mouse or
      19    induce, for example, an RE blockade with

      20    carageen in it.  So it is an intriguing

      21    reiteration of history that in fact in the

      22    human condition this appears to be the case

                                                            165

       1    as well.

       2              If we now look at the patients who

       3    come to us early in life that is before they

       4    really obtain severe infections like GGVS or

       5    CMD, the long‑term survival since the start

       6    of the group is 81 percent and the long‑term

       7    disease‑free survival in patients who are

       8    older is about 56 percent reflecting, in

       9    fact, the problems with infections prior to

      10    the time they come to our shop.

      11              If we look at the different types

      12    of severe combined immune deficiency the vast

      13    majority of X‑ linked disease have not

      14    required cytoreduction before the transplant

      15    and 90 percent of them are long‑term

      16    survivors.  Autosomal recessive now is 78

      17    percent of these and these have now been

      18    looked at specifically at a genetic level.
      19    The ADA deficients are now approaching about

      20    60 percent and I think that result is a very,

      21    very positive one as well.

      22              But the most important thing yet ‑‑

                                                            166

       1              DR. ANDERSON:  Have you ever

       2    determined after this 15, 20 years why ADA ‑‑

       3    is so much different from other ‑‑

       4              DR. O'REILLY:  The basic data that

       5    we think is going on is basically what

       6    happens is the same thing that happens when

       7    you give peg ADA.  That is if you give an ADA

       8    positive graft that can confer enzymatic

       9    capacities on the host which would allow that

      10    individual to generate some T‑cells that may

      11    reject the graft.  And we think that that's

      12    the strongest feature of it.  However, it

      13    should also be noted that every one of the

      14    ADA deficients has been strongly NK positive.

      15    Every single one of them.

      16              Now, the other important point is

      17    that time also helps and once we actually

      18    became clear on what were the correlates of
      19    resistance, that is, patients with NK

      20    positive forms of SCID or kids with ADA

      21    deficient SCID would then automatically go to

      22    busulfan and cyclophosfide for the primary

                                                            167

       1    graft.  Whereas those who were NK negative

       2    and ADA normal could go to graft without

       3    cytoreduction.  And as you can see here,

       4    since 1986 through to the present, 39

       5    patients in our series, 82 percent of those

       6    patients are long‑term survivors.

       7              Now, the critical point to be

       8    raised here, and this is ‑‑ it could be

       9    particularly nice if we had a group of them

      10    here since many of these kids are now in

      11    college.  The key point is that they are

      12    immunologically intact in terms of their

      13    T‑cell function.  If they have not engrafted

      14    with B‑cells, their B‑cell function has been

      15    supplemented by immunoglobulin.  But

      16    increasingly what we are now doing is looking

      17    to secondary grafts to in fact induce the B‑

      18    cell function as well.  And this may require
      19    immunoglacian, or transoimmunoglacian with

      20    fluderapine in the secondary T‑depleted graft

      21    from the same donor.  But the vast majority

      22    of these patients they are basically living

                                                            168

       1    normal lives at home at the present time.

       2              So these results basically showed

       3    that one could engraft endurably reconstitute

       4    T‑cell immunity of the key point is that the

       5    donor T‑cells recognize antigens from the

       6    context of host‑unique HLA determinants.  The

       7    engraftment gives rise to consistent

       8    reconstitution of B‑cell immunity if you

       9    engraft donor B cells.

      10              The critical point is that the

      11    incidence of Graft‑verus‑Host Disease has

      12    been extremely low in the absence of any

      13    other drug prophylaxis and the high

      14    proportion of long‑term disease‑free

      15    survivors that we're recording here has also

      16    been iterated, for example at Duke, at LA

      17    Children's at San Francisco, at several

      18    centers throughout Europe, Australia, China,
      19    and Japan.  In ever instance in which they

      20    have used this approach to T‑cell depletion

      21    without any prophylaxis the same results has

      22    been observed.

                                                            169

       1              Now, when we've looked at this in

       2    the context of patients with leukemia the key

       3    point is, can you overcome Graft‑verus‑Host

       4    Disease?  And this slide is looking at a

       5    large series of individuals and they

       6    principally are looking at individuals who

       7    got no prophylaxis against rejection either

       8    pre‑ or post‑ transplant, because one of the

       9    key points that we have used to actually

      10    ensure engraftment was the introduction of

      11    antithymocyte globulin back in the early 80s.

      12    And this is the important point because these

      13    patients again received nothing except a

      14    lectin separated graft.

      15              And as you can see among these

      16    individuals who engrafted 121 patients had no

      17    TVH, five had grade one, and five had grade

      18    two.  The overall incidence of grade two
      19    Graft‑verus‑Host Disease then was 3.8

      20    percent.  This is a group of individuals

      21    ranging in the age from 18 to 53.  The median

      22    age of this group of patients is 40.  And

                                                            170

       1    there is no grade three and there is no grade

       2    four Graft‑verus‑Host Disease in this

       3    particular grouping.

       4              Looking at overall prophylaxis

       5    either giving ATG pre or post, again, the

       6    same features will out.  Thus, again, T‑cell

       7    depletion alone can in fact obviate the

       8    problem of Graft‑verus‑Host reactions.

       9              Now, when we initially tried these

      10    studies in the early 80s we also were

      11    interested in the unrelated and clearly what

      12    we were also able to show in this

      13    circumstance, again, was that the incidence

      14    of Graft‑ verus‑Host Disease is low.  If

      15    there's no genetic disparity documented

      16    between the donor recipient and the unrelated

      17    circumstance that you can see is a 7 percent

      18    grade two to four.  The only incidence where
      19    we have had a significant incidence has been

      20    in the context of a major class two disparity

      21    where it's about 25 percent of the patients

      22    have developed some evidence of

                                                            171

       1    Graft‑verus‑Host Disease.

       2              This is specifically an update on

       3    the early Kernan experience because I now ‑‑

       4    and I'd be happy to give this to you, but

       5    this is looking at 168 prospectively

       6    evaluated HLA matched recipients of lectin

       7    separated marrow transplants, again,

       8    administered without prophylaxis.  And what

       9    we have looked here at is the number of

      10    T‑cells demonstrated by limiting dilution

      11    analysis.  And what you can see is that the

      12    vast majority of these individuals received

      13    doses ranging between approximately ten to

      14    the fourth, and up to about eight times ten

      15    to the fourth T‑cells.

      16              These are the patients who

      17    developed any evidence of GVH.  There are two

      18    patients who developed grade two GVH and the
      19    rest of these patients had grade one

      20    Graft‑verus‑Host Disease.  Thus, when we

      21    initially published that, in fact, ten to the

      22    fifth clonable T‑ cells per kilogram body

                                                            172

       1    weight was an indicator of, as it were,

       2    threshold dosing for Graft‑verus‑Host

       3    Disease.  The fact is that that is held over

       4    time with the context of HLA‑matched sibling.

       5    It still holds as a very clear indicator of

       6    the risks in terms of quantification.

       7              Over here what we have is over 100

       8    individuals who have received unrelated

       9    marrow transplants studied by exactly the

      10    same type of analysis.  And, again, as would

      11    be expected the levels of T‑cells

      12    administered are pretty much the same.  But

      13    what you observe in this circumstance and

      14    this likely reflect that there are subtle

      15    molecular disparities between donor

      16    recipient.  You can see in a fraction of

      17    these individuals grade one, or as you see in

      18    black, grade two Graft‑verus‑Host Disease
      19    even at doses down to ten to the fourth

      20    T‑cells per kilogram.

      21              Most groups now as they're using

      22    this technique in mismatched marrow

                                                            173

       1    transplants are attempting to give less than

       2    five times ten to the fourth T‑cells and in

       3    general the issue of Graft‑verus‑ Host

       4    Disease has been relatively limited.  And,

       5    again, as I note here, this is grade two

       6    Graft‑verus‑Host Disease in this series.

       7              DR. MILLER:  Rick?

       8              DR. O'REILLY:  Yeah.

       9              DR. MILLER:  So far in your

      10    leukemia studies are you showing us

      11    matched‑sibling donor data for the relateds

      12    or are they a mixture of haplos and matched

      13    siblings?

      14              DR. O'REILLY:  No, right now what I

      15    want to just be sure of is that I get the

      16    biology of the circumstance.  This is looking

      17    at now ‑‑ these are related HLA‑matched donor

      18    recipients or related ‑‑ or unrelated donor
      19    or recipients who are up to one antigen

      20    disparity between donor recipient.

      21              This is the other key that is

      22    important and that is in the context of these

                                                            174

       1    patients, a chronic Graft‑verus‑Host Disease

       2    has also been low.  It's .8 percent in

       3    recipients of matched‑related grafts and as

       4    you can see 9 percent among the unrelated

       5    grafts that we have looked at.  That is again

       6    in the absence of drug prophylaxis.  So

       7    clearly T cell depletion can prevent both

       8    acute and chronic graft versus host

       9    reactions.

      10              When we initially applied this in

      11    the early 80s we expected to see significant

      12    benefits.  But actually in this prospective

      13    analysis we curtailed it because of the fact,

      14    in fact, there was no difference in

      15    T‑depleted and unmodified.

      16              The advantages in terms of getting

      17    rid of graft versus host disease were

      18    countermanded by a very significant incidence
      19    of graft failure.  But it's an important

      20    point for this particular group to understand

      21    that the issue of graft failure is now

      22    something of an historical issue rather than

                                                            175

       1    something that is present.  This was a major

       2    problem before and is becoming less of a

       3    problem as we go along.

       4              We did several studies and I can

       5    show this, but basically in HLA disparate

       6    grafts the predominant populations that we

       7    observed emerging at the time of graft

       8    rejection early after transplant were

       9    host‑type CD‑8 positive T cells that would

      10    exhibit selected reactivity usually directed

      11    against a single HLA class I determinant,

      12    usually HLA B.  And the discriminatory

      13    capacity of these cells in an unrelated

      14    circumstance could be such as to discriminate

      15    molecular microvariants of HLA B or HLA A

      16    that are single amino acid different.  Okay.

      17    So that discriminatory power is very clear.

      18              We have found in rare instances the
      19    emergence of CD‑4 cells that are selected for

      20    class two.  In the matched circumstance they

      21    are invariably CD‑8, they are HLA class one

      22    restricted populations of cells and the

                                                            176

       1    actual determinants that are expressed on the

       2    surface of the donor marrow cells that give

       3    rise to the emergence of these cells inducing

       4    rejection is still not very clear.  Although

       5    at least in one instance HY has been

       6    implicated.

       7              And this just shows you how we

       8    would do these types of analysis.  We would

       9    take blood from the peripheral blood of the

      10    individual and basically look at these

      11    populations of T cells.  And in this

      12    circumstance we have a donor who is unique

      13    determinants are A3, B7 and DR2 an what we do

      14    is to test these against either the donor

      15    populations which you can see can be killed

      16    by these host T cells in the circulation and

      17    then test them against a series of homozygous

      18    cells that share one or another of the
      19    alleles with the donor.  And in this

      20    particular instance we had a CD‑8 population

      21    of T cells of host origin that were

      22    selectively reactive against cells that bore

                                                            177

       1    the B7.  They were reactive against the B7

       2    determinant unique to the donor.

       3              Now, recognizing the T cells were a

       4    critical variable and this was basically

       5    where we were in around 1987‑88 we basically

       6    then went on to try to develop approaches

       7    which would allow us to overcome this.  And

       8    we explored initially more intensive

       9    preparatory cyto reduction but mostly the

      10    depletion of residual host T cells with

      11    antithymocyte globulin.  And in fact the

      12    protocols in this series of protocols with

      13    rigid stopping rules we determined that if we

      14    gave ATG between day five and day 19

      15    post‑grafting we could, in fact, obviate the

      16    problem of immune rejection.  And the

      17    subsequent alteration was to administer

      18    thiotepa in a an attempt to ensure a better
      19    overall engraftment.

      20              And this shows you then the risk of

      21    relapse in ‑‑ I'm sorry of graft failure in

      22    these individuals.  We did not see graft

                                                            178

       1    failures in the matched‑siblings in the

       2    context of younger kids, but only in the

       3    adult population.  But in this population, as

       4    you can see, with the TBI ‑‑ alone without

       5    ATG it was up to 23 percent in the patients

       6    at risk.  And as you can see, when we added

       7    the ATG in the early post‑grafting period we

       8    eliminated graft failures in this period

       9    between day 12 and day 25 to 50.  And what we

      10    found in this circumstance is that we had

      11    eliminated immune rejection.  We no longer

      12    saw the redevelopment of host T cells

      13    reactive against donor.

      14              In those patients who did have

      15    graft failure, what we found was that they

      16    remained full lymphoid chimeras of donor

      17    type, but that they had lost their

      18    hemapoietic grafts.
      19              In contrast, however, when we added

      20    thiotepa that basically has eliminated the

      21    issue of graft rejection to a very, very low

      22    level.  And this actually can be updated now

                                                            179

       1    to be even lower than that.  So thus what we

       2    have seen is by giving this combination of

       3    thiotepa coupled with ATG, we have been able

       4    to overcome the immune rejection, principally

       5    with ATG and with thiotepa then the incidence

       6    of late graft failure post transplant.

       7              The end result of that has been

       8    very salutary.  And this is a slide from a

       9    study that was published recently by Essie

      10    Papadopoulos and Jim Young in blood and she

      11    can detail it, but what we have found is now

      12    in this group of adults who were transplanted

      13    for AML in first remission within three

      14    months of achieving a first remission that

      15    the long‑term disease‑ free survival for this

      16    group is 78 percent despite the fact that

      17    median age for this group is 40.

      18              Now, thus in these particular adult
      19    crowd of individuals all of who engrafted and

      20    none of whom developed grade two

      21    Graft‑verus‑Host Disease the salutary effects

      22    of the T‑depleted graft can be seen.  And as

                                                            180

       1    you can see, the incidence of relapse remains

       2    entirely low.  That's another important point

       3    because what we have found, and this is

       4    looking at the long‑ term risk of relapse in

       5    patients with ALL or AML in first or second

       6    remission.  But since we started this whole

       7    program irrespective of the protocol used,

       8    this is a cumulative incidence of relapse in

       9    this group of individuals which is 25 percent

      10    and is not different from what one would see

      11    with a conventional marrow transplant.  Thus,

      12    in the acute leukemias T depletion has not

      13    been associated with an increment in relapse.

      14              In contrast, however, CML that has

      15    been a really striking problem.  However,

      16    there have been these recent studies

      17    initiated by coal which have shown that in

      18    fact one can administer T cells late in the
      19    post‑grafting period and can induce

      20    remissions.  And, in fact, in a dose

      21    escalation study we've actually been able to

      22    show that for patients recurring with

                                                            181

       1    molecular cytogenetic evidence of disease

       2    doses of ten to the seventh or less T cells

       3    will be able to induce them into durable

       4    molecular emissions without graft versus host

       5    reactions.

       6              One of the striking things that at

       7    least holds true in the matched siblings but

       8    we cannot say in the mismatched circumstance

       9    is that there is this striking alteration in

      10    terms of the risk of Graft‑ verus‑Host

      11    Disease per dose of T cells administered by

      12    the time post grafting.  And as you can see

      13    here, when we have administered T cells as

      14    treatment for example for EBV lymphomas

      15    between zero and six months does of ten to

      16    the fifth ‑‑ to five times ten to the sixth

      17    have been associated with a significant

      18    incidence of GVH.  Whereas if you give those
      19    better than two years out, as you can see,

      20    none of the 12 patients treated have

      21    developed GVH at all.

      22              Thus, there is a dose associated

                                                            182

       1    and a time associated risk of

       2    Graft‑verus‑Host Disease which we believe

       3    likely reflects the capacity of the host or

       4    the residual host antigen presenting cells to

       5    present to the donor cells a suitable target

       6    for the initiation of a Graft‑verus‑Host

       7    response.  And as a result of that, if you

       8    now combine the T‑depleted graft and then

       9    give DLI for evidence of molecular

      10    cytogenetic or clinical relapse the long‑term

      11    disease‑free survival for these patients

      12    transplanted within the first year of

      13    diagnosis is almost 71 percent and for those

      14    greater ‑‑ is still 47 percent.  Thus, these

      15    results are very, very similar to what are

      16    basically considered to be the best around in

      17    the context of a conventional graft, except

      18    there's no GVH.
      19              Now, when we tried to do this in

      20    mismatched circumstances this is a long and I

      21    would have to say sort of like on all‑souls

      22    day you get down on your knee and you do your

                                                            183

       1    litany of the saints.

       2              And what we tried to do then was to

       3    go through this whole thing, and

       4    unfortunately it was incredibly difficult.

       5    We set up an approach which basically was as

       6    follows.  We would change one ‑‑ make one

       7    alteration in the cytoreductive regimen.  We

       8    would have a strict stopping rule, because we

       9    did not want more than two to three

      10    rejections per group.  When we used the

      11    amount of rejection that you would anticipate

      12    seeing for a given level of genetic disparity

      13    if the graft was unmodified.  And based on

      14    that type of a ruling, we were able to do in

      15    very small groups of patients 25 at most a

      16    series of studies that were stepwise.  And,

      17    in fact, as you'll see in many of these they

      18    were even smaller because the limitation in
      19    terms of graft failure was really quite

      20    significant.  And yet, again, when we added

      21    antithymocyte globulin again the incidence of

      22    graft failure was significantly lower in this

                                                            184

       1    particular realm.  And when we got down here

       2    into using either ara‑C or thiotepa, the

       3    incidence of graft failure really would not

       4    be much different from what would be observed

       5    with an unmodified graft.

       6              Now, this is the last study that is

       7    the current one and I'll talk about and that

       8    is based on studies that were done by Frank

       9    Aversa who worked with us to learn the lectin

      10    separated technique and then went one huge

      11    jump further.  That is, he used the studies

      12    of Yier Reisner demonstrating that in fact

      13    you could enhance engraftment in

      14    histo‑incompatible mice by giving a higher

      15    dose of cells.  And so what they have used is

      16    CD34 position E‑negative peripheral blood

      17    stem cells.  And in our series now there are

      18    22 patients that I'll talk about.
      19              The critical point also to be

      20    raised though here is with the

      21    lectin‑separated marrow, among those who

      22    achieve durable engraftment as you can see

                                                            185

       1    the incidence of grade three Graft‑verus‑Host

       2    Disease is minimal in all of the series.

       3    Unfortunately, when we have used the CD34

       4    positive selection by separate followed by

       5    E‑negative we have a very appreciable

       6    incidence of Graft‑verus‑Host Disease that we

       7    had not anticipated.  Our approach though is

       8    different from the aversa approach in that

       9    the E‑step or the Rosetting step is done

      10    after the CB‑34 selection, whereas he is

      11    doing it before.  And that may have very

      12    significant differences in terms of the T

      13    cells there.

      14              Of the 27 patients that we have

      15    done ‑‑ I'm sorry, this is the 27 patients

      16    done by aversa, and as you can see

      17    engraftment has been very high; 25 of the 27

      18    patients have achieved it.  They've had a
      19    very, very low incidence of Graft‑verus‑Host

      20    Disease.

      21              In our group of patients, we again

      22    have looked at this in terms of the

                                                            186

       1    engraftment that has been observed and what

       2    we observe is that with the TBI thio side

       3    regimen using the lectin plus CD34 we have

       4    endurably engrafted 20 of 22 patients.  We

       5    have only two graft rejections.

       6              The patients that we have been

       7    doing this in have been consistently very bad

       8    cases in terms of they are late in disease

       9    and unfortunately that slide is missing here.

      10    But there are 22 patients thus far enrolled.

      11    We've had two that have had graft failures.

      12    As you can see the time to engraftment has

      13    been very short, as early as nine days to an

      14    ANC greater than 500.  But the important

      15    point here is that almost half of this group

      16    has in fact developed grade two to four

      17    Graft‑verus‑Host Disease.  In most instances

      18    this has been treatable, but in certain
      19    instances it has in fact led to lethal

      20    sequela.

      21              Eight of these patients are now

      22    long‑term survivors but, again, it's very,

                                                            187

       1    very short.  And this Kaplan Meyer has put up

       2    with great risk because the vast majority of

       3    these patients are in this period and these

       4    represent the earliest efforts at this.  So

       5    this is a very unstable curve at the present

       6    time.

       7              Still in all what this has shown us

       8    is that now we have a mechanism which allows

       9    us to achieve consistent engraftment.  What

      10    I've been a little bit distressed at is that

      11    we have mor GVH than we had anticipated.

      12              The other key thing that I wanted

      13    to give to the committee because it's

      14    important because I think we are now at the

      15    point where we have overcome engraftment.  We

      16    have techniques that potentially can overcome

      17    Graft‑verus‑Host Disease.  What are the

      18    central issues?  And the central issue remain
      19    infection, particularly among the adults.

      20              And this is looking at the

      21    proportion of patients with opportunistic

      22    infections looking at SBA‑ negative‑related

                                                            188

       1    grafts without ATG or with ATG, as you an

       2    see, there's a significant increment here.

       3    These are unmodified related marrow

       4    transplants and as you can see the T‑depleted

       5    graft is not associated with any increase in

       6    the incidence of infection over what we would

       7    see with an unmodified transplant.  But what

       8    you do see is a further increase in the

       9    patients who have received unrelated grafts.

      10    And this is seen both in adults and in kids.

      11    But as you can see, there's a striking

      12    difference in terms of the overall incidence

      13    of infection in children to adults.

      14              Now, why would that be?  Well,

      15    there are some elegant studies that have been

      16    done by Trudy Small where we have looked at

      17    these patients long‑term.  And the

      18    observation is that irrespective of the type
      19    of transplant administered, be it an

      20    autologous graft an HLA‑matched graft from a

      21    related donor, or an unrelated graft or now

      22    even a mismatched graft the children all seem

                                                            189

       1    to come back relatively rapidly within about

       2    three to six months.  Whereas the adult

       3    recipients tend to be more prolonged.

       4              Now, unfortunately, and you can see

       5    this not only in terms of recovery of T cells

       6    but also in terms of PHA responses, for

       7    example, individuals receiving lectin graft

       8    from an unrelated compared to a related

       9    they're exactly the same, and here you see

      10    the autologous.  There are three

      11    superimposable grafts.

      12              Now, why would the adult be a

      13    little longer?  Well, unfortunately this is

      14    an old study that we did years ago, but the

      15    fact of the matter is, once we get to 21

      16    we're on the down side.  We are on the dark

      17    side of it because in fact the thymus is

      18    really taking a deep swing.  And the fact of
      19    the matter is that here's our median age of

      20    our patients now transplanted for leukemia

      21    with T‑depleted grafts.  And thus the thymic

      22    environment may be significantly impaired,

                                                            190

       1    but there has to be something beyond that

       2    because this is looking now at the recovery

       3    of T cells following these related marrow

       4    transplants that are lectin separated in

       5    adults, median age 40, versus the unrelated.

       6    And there is a really striking difference in

       7    terms of the recovery of the number of T

       8    cells.  Here we're looking at CD3 positive

       9    cells.  You can look at this particularly

      10    among the CD4s and that is that the unrelated

      11    group takes a much longer period of time and

      12    the level of recovery appears to be

      13    significantly impaired.  And I would like to

      14    say, this is not the case, but this appears

      15    to be reiterated now in the haplotype

      16    disparate grafts as well.

      17              And you can also see this

      18    strikingly in terms of function, looking at
      19    related unmodified or lectin separated

      20    grafts.  They are here, and then you look at

      21    the unrelated graft they're much, much

      22    slower.  And so one of the concerns that we

                                                            191

       1    have and one of the reasons why I'm so

       2    interested in what Joanne is talking about is

       3    in fact we may have a major problem in terms

       4    of the capacity of the marrow progenitor

       5    population that is T‑ depleted now to

       6    actually migrate to the thymus or to develop

       7    within the thymus of the adult such as to

       8    allow for appropriate reconstitution of

       9    T‑cell populations.  And the disturbing

      10    feature about this particular slide, if I can

      11    get back there ‑‑ this one you have to think

      12    about because remember if you're doing an

      13    unrelated marrow transplant the marrow is all

      14    derived from a population of adults.

      15              It's T‑depleted and administered.

      16    So the graft can be considered to be at least

      17    in terms of time biologically the same.  Yet,

      18    in the young child the immune reconstitution
      19    will go up here.  And yet in the adult it

      20    takes really for a very long period of time.

      21              So what we are concerned about is

      22    that the environment of the adult may be

                                                            192

       1    considerably less plastic, less capable of

       2    basically allowing for appropriate

       3    reconstitution.  One of the issues now that

       4    we are back to which is exactly where we

       5    started in the mouse when we started with

       6    T‑depleted grafts when VonVormer and Sprint

       7    first did this is the same.

       8              That what we now really have to

       9    think about are what are the genetic

      10    restrictions that may limit the migration of

      11    these cells to thymus.  What are the kinds of

      12    alterations that could in fact limit the

      13    recovery of the immune function either in the

      14    context of the molecularly disparate

      15    unrelated donor recipient paring or

      16    potentially the haplotype disparate grafts as

      17    we're doing more and more of these for the

      18    future.
      19              I'll stop there.

      20              DR. VOSE:  Thank you.  Any

      21    questions or comments?

      22              DR. SALOMON:  In this last slide I

                                                            193

       1    just wanted to make sure I understood.  There

       2    is or there was not a difference in the

       3    median age of the related versus the

       4    unrelated patients?

       5              DR. O'REILLY:  Oh, I'm sorry, I'm

       6    sorry.

       7              DR. SALOMON:  You got me a little

       8    bit because initially you introduced this

       9    slide saying the mean age was 40.

      10              DR. O'REILLY:  It is.

      11              DR. SALOMON:  And then you're

      12    saying that the only difference was related

      13    versus unrelated.

      14              DR. O'REILLY:  No, no.

      15              DR. SALOMON:  And then later you

      16    kind of segued into a different state.

      17              DR. O'REILLY:  What I'm saying is

      18    that if you look at the reconstitution ‑‑ put
      19    that back on.

      20              The fourth from the last.

      21              DR. SALOMON:  This one here ‑‑ this

      22    is adults.  These are all adults.  This is

                                                            194

       1    looking at reconstitution in a matched adult

       2    who received a T‑ depleted transplant.  This

       3    is a quote/unquote matched‑ unrelated adult

       4    receiving a transplant.  Okay.

       5              And what we observe here ‑‑ shown

       6    here as well, is that the adult receiving the

       7    unrelated graft is very, very slow in

       8    comparison to the HLA‑matched adult.  Now, if

       9    you go back here, if you look at the child on

      10    the other hand, whether it's unrelated or

      11    otherwise, they all come back.  And this is

      12    particularly shown here.  That is that the

      13    SBA‑negative related is here, SBA‑unrelated

      14    is here, the autologous transplant is here.

      15    So what I'm saying is that adult marrow from

      16    unrelated donors administered to a child

      17    leads to abrupt immunologic reconstitution

      18    and that reconstitution cannot be
      19    distinguished from that which you would

      20    achieve of an autologous graft.  That same

      21    adult marrow put into an adult individual on

      22    the other hand ‑‑ I'm going the wrong way ‑‑

                                                            195

       1    ‑‑ gives you this.  And so it's not just that

       2    microenvironment of the adult is less able to

       3    reconstitute because this adult HLA‑ matched

       4    sibling also has a relatively atrophied

       5    thymus.  It goes beyond that.  And what I'm

       6    concerned about is that molecular disparities

       7    between donor and recipient may in fact

       8    affect initial traffic to the thymus or the

       9    maturation within the thymus.

      10              And this is kind of, you know, from

      11    a safe point, you know, someone asked me one

      12    time, what are you going to do, and I said,

      13    "I'm going to do research."  He says, "Ah,

      14    yes, it was my generation to search and yours

      15    to research."

      16              DR. O'REILLY:  The fact was that

      17    studies suggesting that in fact there were

      18    modulations of the migration of these early
      19    progenitor populations that could be in fact

      20    H‑2 modulated.  In other words that there

      21    were genetic differences in the mouse that

      22    H‑2 disparities could alter mobilization and

                                                            196

       1    movement was that back in the 1970s by OCSC

       2    ‑‑ and we unfortunately are going to have to

       3    revisit this.

       4              Alternatively what we have to do is

       5    to develop new approaches which would allow

       6    us to make a better thymic environment such

       7    as the possibility of a thymic graft or the

       8    use of certain kinds of cytokines like aisle

       9    seven or IGF one which can actually promote

      10    thymic cellularity.

      11              DR. VOSE:  Okay.  Any other

      12    questions, comments?  Jean?

      13              DR. HENSLEE‑DOWNEY:  Well, I'd just

      14    add the comment that I didn't show this data,

      15    but we do have data in the haploidentical

      16    transplant where our outcomes, whether they

      17    be GVHD or even survival have not really

      18    segregated based on the recipient age, but
      19    they have segregated based on donor age.  And

      20    furthermore in MDP they've looked at

      21    unrelated ‑‑ there are unrelated donors

      22    although they are all adults, but there is an

                                                            197

       1    impact on the age, the older age of an

       2    unrelated donor and worser outcomes with

       3    regard to GVHD and ‑‑

       4              DR. O'REILLY:  That has to be added

       5    because in real terms older donors, when

       6    you're talking about donors over the age of

       7    50, the reconstitution of hematopiesis is

       8    poor, the incidence of graft failure is poor

       9    as well.  You know, you're absolutely correct

      10    on that.  I don't mean in any way to say that

      11    it's all in the context of hosts.  I just

      12    think that there are environmental issues in

      13    the host that are ‑‑

      14              DR. HENSLEE‑DOWNEY:  But it's

      15    interesting and actually in designing these

      16    studies we do have to pay attention to donor

      17    age also.  I think it's an important

      18    parameter.  And in our center we are now
      19    actually sometimes going to a younger donor

      20    because in the haploidentical setting you

      21    often have many available donors and we might

      22    take a child who is even more mismatched

                                                            198

       1    rather than older donor who is less

       2    mismatched.

       3              DR. O'REILLY:  We too, I agree.

       4              AUDIENCE:  I'm a little mystified

       5    by why you don't see B cells in your SCIDS

       6    that were not cyto‑reduced.  If you're

       7    getting engraftment of multi‑lineage

       8    progenitor cells, so you're getting erythroid

       9    or myeloid engraftment it would suggest that

      10    you're not.

      11              DR. O'REILLY:  If you don't

      12    cytoreduce the patients they will get

      13    engrafted with T cells only.

      14              AUDIENCE:  Okay.  Okay.

      15              DR. O'REILLY:  You don't get the

      16    rest of the situation.  And even if you

      17    cytoreduce with busulfan and cyclophosphamide

      18    in not only SCIDs, but in any of the
      19    metabolic diseases oftentimes you are left

      20    predominantly with host hematopoiesis, donor

      21    T cells and then a mix after that.

      22              AUDIENCE:  Thanks.

                                                            199

       1              DR. VOSE:  Okay.  Other questions

       2    or comments?

       3              Okay.  Why don't we break for ‑‑

       4    yes ‑‑

       5              DR. SIEGEL:  For the record, there

       6    was a remark there or two earlier this

       7    morning about FDA jurisdiction that I wanted

       8    to clarify for the record.  It's not really

       9    the topic of these discussions, but as people

      10    read the transcript and view the video tapes,

      11    I wanted to make sure that we haven't

      12    increased confusion in a very confusing area.

      13    Dr. Litwin in noting the increasing number of

      14    IND we received also noted that we received

      15    largely INDs that involved growth factor

      16    devices or other regulated materials aside

      17    from the allogenic cells themselves, and that

      18    is correct.  However his remarks, and I don't
      19    remember his exact words, which should not be

      20    misconstrued to indicate that the agency

      21    position is that the cells themselves are not

      22    a regulated product indeed as Dr. Marti

                                                            200

       1    summarized in your handouts there was a

       2    Federal Register notice in January indicating

       3    that we consider unrelated allogeneic cells

       4    whether of peripheral blood or umbilical cord

       5    to be a private group that will come under

       6    FDA regulation and we were seeking input as

       7    to what standard should be applied or in lieu

       8    of that the possibility of implementing

       9    alternative regulatory approaches.  Those

      10    were discussed in a September meeting that

      11    was summarized and that's under discussion.

      12    But I did want to make sure that we weren't

      13    creating more confusion because those remarks

      14    do represent in fact the current approach to

      15    regulation in that area.

      16              DR. VOSE:  Okay.  Why don't we

      17    break for lunch and we'll come back for

      18    discussion at 1:30.
      19                   (Whereupon, at 12:30 p.m., a

      20                   luncheon recess was taken.)

      21

      22

                                                            201

       1          A F T E R N O O N   S E S S I O N

       2                                             (1:35 p.m.)

       3                COMMITTEE DISCUSSION

       4              DR. VOSE:  Why don't we just frame

       5    a discussion with respect to what the

       6    questions were from the FDA.  I think they

       7    pretty much go over the things that we need

       8    to discuss.  I think everyone has the

       9    questions.  It's on the second sheet of the

      10    agenda sheet.

      11              Question number one deals with kind

      12    of how to frame future studies with respect

      13    to looking at this issue and first of all it

      14    talks about basically wondering if it is

      15    possible or not possible to do a randomized

      16    trial with an unmanipulated graft in this

      17    situation.  And assuming that it's not

      18    possible which I think most people would say,
      19    to discuss the feasibility, advantages and

      20    disadvantages of an active controlled trial

      21    such as randomization to another

      22    investigational modality or randomization to

                                                            202

       1    arms that differ only by the amount of T‑cell

       2    depletion or comparison to historical or

       3    registry experience.

       4              Rich, do you want to start any

       5    discussion on any of those issues with

       6    respect to what do you think how could best

       7    frame a trial in this circumstance?

       8              DR. O'REILLY:  I think that we're,

       9    you know, getting close to a situation where

      10    at least two or three approaches now are

      11    showing very exciting results.  I mean,

      12    obviously I think clearly Jean has some very,

      13    very good stuff.  I think Franco has some

      14    good stuff.

      15              I think we're in the early stages

      16    of the protocol that we've had and we're

      17    making some adjustments.  But I am still

      18    impressed that, you know, we have some three
      19    edge and disparate circumstances without much

      20    in the way of GHV, and that I knew before.

      21    But I think the other issue that we were

      22    concerned about was engraftment, and now we

                                                            203

       1    can get engraftment.  So I think the

       2    possibility of doing it, you know, doing a

       3    trial in which you have one or another type

       4    of transplant could be done.

       5              One of the problems that I have

       6    right now in terms of formulating this though

       7    is ‑‑ you know, I'm sure it would seem like

       8    something of a cottage industry, but it

       9    really isn't that much so.  But there are

      10    some tremendous levels of sort of experience

      11    that go into the whole issue of cytoreduction

      12    regimen used.  And so all I would say is, you

      13    know, given the fact that we're kind of

      14    early, it may be worthwhile to consider it in

      15    the context of a whole package rather than

      16    one particular technique versus another.  And

      17    I don't know if that's going to be easy to

      18    really stomach.
      19              But you're asking this specifically

      20    in terms of what would be required for

      21    licensure of a product.

      22              DR. VOSE:  I think that's the FDA's

                                                            204

       1    question, yeah.

       2              DR. O'REILLY:  Yeah, I would say,

       3    again, you know, some kind of standard

       4    approach would be appropriate for at least

       5    for certain diseases you could do it that

       6    way.

       7              DR. VOSE:  So you're saying for

       8    comparison of two techniques?

       9              DR. O'REILLY:  Two ‑‑ yeah, two

      10    approaches to the haplotype disparate graft.

      11              DR. VOSE:  So comparing two

      12    experimental techniques, one versus the

      13    other?

      14              DR. O'REILLY:  Yeah, I think that

      15    that potentially could be done.  And I think

      16    to say we will ‑‑ the only other approach

      17    would be to ask a simpler question.  That is,

      18    you take a technique and you compare it, you
      19    know, current therapy and say, at this point

      20    we could potentially do a better job if we do

      21    these patients earlier in disease.  So let's

      22    say you take good risk cases quote/unquote

                                                            205

       1    who are in, for example, a second remission

       2    of acute leukemia or are relatively late in

       3    the chronic phase of CML and you're now going

       4    to compare them versus a chemotherapeutic

       5    approach which has a very low likelihood, but

       6    has some finite likelihood, you know, could

       7    you do that.  And that might also be at least

       8    something that could be reasonable one.

       9              DR. VOSE:  So for patients that do

      10    not have an HLA identical sibling, to compare

      11    that versus some standard chemotherapy which

      12    we know is not very beneficial.  And that's

      13    not a very fair comparison ‑‑ I don't know,

      14    it's hard to say what's fair.

      15              DR. O'REILLY:  Well, I think that

      16    that one may be bucked.  But, I mean, one of

      17    the questions that is coming up now, for

      18    example, in a good risk case, if you have an
      19    acute leukemia either first or second

      20    remission and you have a choice between

      21    continuing chemotherapy versus an unrelated

      22    marrow transplant, there are several groups

                                                            206

       1    that in the first remission would ‑‑ there

       2    are several groups that would think, you

       3    know, you shouldn't be doing unrelateds in

       4    the first year of remission and other groups

       5    that you should.  My own read of it is that's

       6    actually probably a decent and ethical

       7    question at the time.

       8              I don't think we're quite there

       9    with the haplotype circumstance yet to be

      10    able to ‑‑ although, you know, I ‑‑ well, you

      11    certainly are.

      12              DR. HENSLEE‑DOWNEY:  Yeah, I mean,

      13    I think that in an experience center you

      14    might get a little bit closer to that, but I

      15    think that it is a developing technology and

      16    that I don't think that you would open it up

      17    under those circumstances because you know

      18    you're going to have a learning curve in new
      19    centers necessarily.  That would be one

      20    caveat for that.

      21              DR. VOSE:  But I think any of these

      22    studies need to be done in experience centers

                                                            207

       1    because there's ‑‑ it's not only the

       2    transplant it's the after care.

       3              DR. HENSLEE‑DOWNEY:  Yes, without

       4    question.

       5              DR. O'REILLY:  But you have to have

       6    ‑‑ the other arm has to have a very clear,

       7    finite possibility.  Like, for example, a

       8    controlled trial of T‑depleted transplants

       9    from haplotype disparate donors for severe

      10    combined immune deficiency is inappropriate

      11    insofar as the disease is uniformly lethal.

      12    You go one versus another.

      13              DR. VOSE:  Right.

      14              DR. O'REILLY:  Or an unrelated

      15    transplant versus a T‑depleted haplotype

      16    disparate graft, I'd like to get that

      17    finished with and that's probably reasonable.

      18    That's not necessarily something that's going
      19    to be marketing kind of a thing.

      20              DR. HENSLEE‑DOWNEY:  With regards

      21    to the patient population, in large part

      22    that's controlled by the referring physician,

                                                            208

       1    you know, when you get right down to it.

       2              DR. KURTZBERG:  In managed cared.

       3              DR. HENSLEE‑DOWNEY:  Or managed

       4    care, this is true.

       5              DR. VOSE:  I think Dr. Miller had a

       6    comment.

       7              DR. MILLER:  But I think for the

       8    purpose of this discussion we are not so much

       9    talking about the utilization of

      10    transplantation, we're looking at ways of

      11    trying to determine the effectiveness of a

      12    technique, not the role of transplantation.

      13    And I think the question has to go back down

      14    to how are you going to compare a method

      15    versus something else if you don't have a

      16    standard.  And I guess one question I have,

      17    and I don't know if anybody has this data, if

      18    you're talking about potentially looking
      19    compared to ‑‑ if you say you can't do a

      20    randomized trial in haploidentical

      21    transplants because nobody quote does

      22    non‑T‑cell‑depleted haploidentical

                                                            209

       1    transplants.  Is there any comparable

       2    database that you could use for historical

       3    controls?  I don't think there is.

       4              DR. O'REILLY:  Is there a

       5    comparable database for three antigen

       6    disparate?

       7              DR. MILLER:  Right.

       8              DR. O'REILLY:  Yeah, there are some

       9    that have been done in Seattle, and there are

      10    certainly several in the literature.  And ‑‑

      11              DR. MILLER:  But they are years

      12    old.  They're not contemporary.  I mean, over

      13    the last ten years.

      14              DR. O'REILLY:  Yeah, but they're in

      15    the cyclosporin era.

      16              DR. MILLER:  And we do them

      17    regularly all the time.  And ‑‑

      18              DR. O'REILLY:  Not in three antigen
      19    ‑‑

      20              DR. VOSE:  No, no, three antigen

      21    non‑T‑ depleted?

      22              DR. MILLER:  Oh, not on modified.

                                                            210

       1              What they're looking at from here,

       2    my understanding is that you have to figure

       3    out ‑‑ if a sponsor is going to come and say,

       4    I have this T‑cell depletion technique, I

       5    want to get it approved.  In order to get it

       6    approved I have to prove equivalency, I

       7    think, and decreased Graft‑verus‑Host Disease

       8    against something.  And it's either a

       9    randomized trial which is the gold standard

      10    or in the case of the randomized trial cannot

      11    be done, well, controlled prospective trials

      12    against a reasonable controlled group.  And I

      13    guess the first question we have to ‑‑ is it

      14    possible to have a reasonable control group

      15    that's not modified.  And I think the answers

      16    are no.

      17              And then the second question is, I

      18    don't ‑‑ how can you ‑‑ the question you
      19    asked here, I mean, my feeling is that

      20    there's no reasonable, unmanipulated that's

      21    in the same generation that's going to be

      22    robust enough to be able to show a

                                                            211

       1    difference.

       2              The second thing is, are you able,

       3    are you allowed to compare to experimental

       4    arms when either ‑‑ to try and get one

       5    approved?

       6              DR. SIEGEL:  Well, I think that ‑‑

       7              DR. MILLER:  I mean, you asked us

       8    whether it happens, but ‑‑

       9              DR. SIEGEL:  My response is, how

      10    can we be asking that question.  The answer

      11    is that we do permit trials which compare to

      12    experimental therapies and we'll approve one

      13    on the basis of showing superiority to the

      14    other if we're comfortable with the

      15    presumption that the other is not harmful.

      16    I'm speaking now in broad terms, not

      17    specifically in engraftment.  So in treatment

      18    of any disease, if you have two therapies and
      19    two compared to experimental therapies and

      20    show one to be superior and we know the

      21    inferior one not to be harmful or can presume

      22    that, we will and can approve the superior

                                                            212

       1    one.

       2              Showing two experimental therapies

       3    to be equivalent has no bearing on

       4    establishment of efficacy.  Such a trial may

       5    establish efficacy, but it would only

       6    establish efficacy as a historical control

       7    trial in which you would ‑‑ showing they're

       8    equivalent tells you nothing about efficacy.

       9    If you're presuming efficacy on the basis of

      10    that trial, you're presuming efficacy on the

      11    basis of comparing the outcomes on either or

      12    both arm to the expected outcome without

      13    therapy.

      14              DR. O'REILLY:  Okay.  But that then

      15    ‑‑ that answers your question and that comes

      16    down to it.  And that is, what is the

      17    efficacy of a transplant versus current

      18    chemotherapy?  That is the appropriate
      19    approach.  It will not be necessarily

      20    satisfying but in very real terms either the

      21    FDA has to do it as a prospective trial

      22    comparing the two or has to look at it

                                                            213

       1    retrospectively and say, is this better than

       2    zero?  Okay.  Because that's what several

       3    chemotherapeutic regimens would be.

       4              DR. KURTZBERG:  If you got a group

       5    of experts together and defined essentially

       6    stopping rules and said, you know, if this,

       7    this, and this happened related to graft

       8    failure and GVH, et cetera, we would stop the

       9    trial.  You could also do some prediction of

      10    statistically seeing a 10 percent improvement

      11    or 20 percent improvement over what your

      12    historical controls have shown or what your

      13    ideal is.

      14              DR. VOSE:  But I think the problem

      15    is that it's a concern about what the

      16    historical control ideal is.  There's a wide

      17    range of what is seen, and in, you know,

      18    particular patient populations there may not
      19    be a very good historical control.  I think

      20    that's the point that Carole was talking

      21    about.  So it's hard to compare to something

      22    that you don't exactly know what the numbers

                                                            214

       1    are.  And a lot of times in this particular

       2    situation it's difficult for the FDA to use a

       3    historical control for those reasons.

       4              DR. KURTZBERG:  The pediatric

       5    oncology group has been trying for 18 months

       6    to get a trial going comparing

       7    transplantation to conventional chemotherapy

       8    for kids with ALL and second CR.  And it

       9    keeps going around and around the table and

      10    the problems are what kinds of transplants

      11    will be allowed and who has the expertise to

      12    do which kinds?  And haplos go in and haplos

      13    go out, and I mean, it's interesting, but

      14    they haven't even been able to get consensus

      15    to get even, you know, deciding on what kinds

      16    of transplants would be considered valuable.

      17              DR. VOSE:  Karen?

      18              DR. WEISS:  I just wanted to say,
      19    in prior discussions with this committee,

      20    we've talked before about the topic of

      21    whether or not you have to actually show that

      22    the ‑‑ I mean, ultimately what Dr. Henslee‑

                                                            215

       1    Downey said earlier, you really want to

       2    improve patient survival.  But certainly in

       3    the past, and even in our prior approval of

       4    things like growth factors for improving

       5    neutrophil recovery post, you know,

       6    transplantation we haven't really addressed

       7    the issue of whether transplantation, per se,

       8    is an appropriate therapy for a particular

       9    disease.  We just looked at within that

      10    transplant context is it doing something

      11    beneficial to the patient which, I guess,

      12    gets to the dilemma of whether in this kind

      13    of setting you want to look at a trial to

      14    really decide whether or not transplant

      15    itself s a better or therapeutic option than

      16    more conventional therapy or are we just

      17    trying to use some of these purging and other

      18    types of techniques to say in this particular
      19    context using this technique improves your

      20    incidence of acute and chronic GVHD and the

      21    relatively speaking shorter‑term outcomes.

      22    So, I mean, I've heard both things being

                                                            216

       1    discussed ‑‑

       2              DR. VOSE:  Compared to what though?

       3              DR. WEISS:  Well, that's where the

       4    ‑‑

       5              DR. VOSE:  That's the problem.

       6              DR. WEISS:  ‑‑ that's the

       7    fundamental problem which is why we've had

       8    such a dilemma with these kinds of studies.

       9              DR. VOSE:  Exactly.  So it's kind

      10    of a circular question.  I think that ‑‑

      11              DR. O'REILLY:  Can I ask a question

      12    of the FDA though, or in this regard?  In the

      13    context of a T‑ cell depleted marrow

      14    transplant, for example, for severe combined

      15    immune deficiency, there you have a disease

      16    that is uniformly lethal.  And back in 1980

      17    when we were talking about this, it was a

      18    uniformly lethal disease for which there was
      19    no approach except this kind of a

      20    circumstance.  Does efficacy depend upon a

      21    randomized trial?  I mean, I don't think that

      22    there's anyone around who would not recognize

                                                            217

       1    the efficacy of T‑depleted graft for severe

       2    combined immune deficiency and no one would

       3    consider it to be even remotely ethically

       4    appropriate not to administer a transplant to

       5    a kid with severe combined immune deficiency.

       6              So, I mean, I honestly ‑‑ I think

       7    the only appropriate control if we were going

       8    to ask a manufacturer to come up with a trial

       9    would be can he show us something better than

      10    current therapy lacking a transplant.

      11    Because otherwise these patients cannot be

      12    transplanted now unless you sort of sit

      13    around for an unrelated donor.  And it would

      14    seem to me that, you know, you are a little

      15    bit caught.  Either you do the randomized

      16    trial or at least you have to sort of accept

      17    potentially some type of a control statement

      18    of what chemotherapy can do.
      19              DR. VOSE:  But I guess from a

      20    manufacturer standpoint to do a trial just in

      21    SCID patients, I mean, would be very

      22    difficult to do that.

                                                            218

       1              DR. O'REILLY:  No, I used that as

       2    an example because I think a haplotype

       3    disparate graft in the context of an

       4    individual where we don't have an unrelated

       5    donor, and, you know, there's a large

       6    proportion of patients who don't have them

       7    who have an active disease, I think that this

       8    is clearly an approach which can potentially

       9    be cured.  And the real issue is what is the

      10    ‑‑ well, you've asked it, what is the

      11    standard against which you are going to

      12    compare that?

      13              DR. VOSE:  Right.

      14              DR. O'REILLY:  And how do you

      15    construct it?

      16              DR. VOSE:  That's right.

      17              DR. SIEGEL:  Was that a question to

      18    the FDA or not?
      19              DR. O'REILLY:  Yeah.  I think the

      20    question is, is the issue of efficacy in this

      21    kind of a circumstance always contingent upon

      22    an randomized trial.  And if it is so, then

                                                            219

       1    the other issue is, what will be the

       2    limitations or let us say stopping rules for

       3    such a trial?

       4              DR. SIEGEL:  And by a "randomized

       5    trial" you mean a randomized trial between a

       6    two‑cell depleted transplant regimen and a

       7    non‑transplant regimen?  Or I'm not sure what

       8    you're asking.

       9              DR. O'REILLY:  Yeah.

      10              DR. SIEGEL:  Okay.  Well, let me

      11    try to restate some things that probably need

      12    to be said.  First of all, there is no

      13    setting in which a randomized trial is

      14    absolutely essential for approval, but

      15    there's no setting in which a randomized

      16    trial doesn't generate better data than other

      17    approaches.

      18              I think that the issue you're
      19    getting ‑‑ the question you're getting at is

      20    the same one that Dr.  Weiss was trying to

      21    address which is, one could either compare a

      22    two‑cell depleted transplant to a non‑

                                                            220

       1    transplantation approach or to a different

       2    transplantation approach.  In that regard we

       3    have phased one issue which I'll reiterate.

       4    We've faced and brought before this committee

       5    in '94 ‑‑ I always say "this committee"

       6    although I recognize none of you were here.

       7              DR. VOSE:  I was here.

       8              DR. SIEGEL:  You were.

       9              DR. VOSE:  I was here.

      10              DR. SIEGEL:  The very question

      11    because it was being asked as noted regarding

      12    the CSFs or whatever studies were showing

      13    simply that CSFs promoted engraftment whether

      14    it was of marrow or peripheral blood or

      15    whatever depending on the year, and the

      16    patients were engrafting better, the patients

      17    were ‑‑ or in the case of high‑dose

      18    chemotherapy they were tolerating high‑dose
      19    chemotherapy.  It wasn't      who were

      20    tolerating it better, but the question kept

      21    arising that there had yet to be in many of

      22    the disease settings in which those were

                                                            221

       1    shown any clear cut evidence that there was

       2    an indication for myelolative therapy or

       3    high‑dose chemotherapy.

       4              The standard that this committee

       5    recommended and that we applied was ‑‑ and

       6    there was a tendency to do those trials for

       7    some agents that had relatively marginal

       8    effects there was a tendency to study them

       9    with ‑‑ not in the marrow setting, but in the

      10    chemotherapy setting with extremely out in

      11    left field, if you will, compared to

      12    mainstream medicine protocols because only

      13    what those highly oblative protocols could

      14    they show that adding their agent made a

      15    difference.

      16              This committee recommended that it

      17    should not matter ‑‑ it should not be the

      18    burden on the sponsor of a trial for a
      19    therapy that is supportive of a hematopoietic

      20    transplantation to demonstrate the benefits

      21    of transplantation, per se.  That, however,

      22    they should not use a regimentation whether

                                                            222

       1    that be transplantation or chemotherapy

       2    unless it is one that is ‑‑ and I won't have

       3    the exact words ‑‑ but is that is reasonably,

       4    widely accepted within the community as a

       5    reasonable approach to the treatment of the

       6    disease.

       7              So that's the standard that we

       8    apply now.  It doesn't have to be that it's

       9    accepted as the standard approach, but a

      10    reasonable approach to transplantation.  If

      11    you can then improve transplantation

      12    outcomes, you need not show the role of

      13    transplantation in the disease.

      14              So what we are facing in these

      15    diseases, however, is in some cases, cases

      16    where the role or transplantation is not yet

      17    established, in other cases where I guess

      18    it's more widely established.  But what we
      19    are anticipating looking at are specific

      20    manufacturer's products.  I have a monoclonal

      21    antibody or the manufacturer does, or a coded

      22    bead, or a device machine that's going to get

                                                            223

       1    rid of T cells and they want to claim that

       2    that contributes something.

       3              So I think the answer to your

       4    question is, you might be able to do a study

       5    compared to a non‑ transplantation regimen if

       6    you had ancillary data showing that the

       7    device contributed to the success of

       8    transplantation which may or may not have to

       9    be clinical trial data.  But you would

      10    certainly have to show that ‑‑ you would have

      11    to make the case that transplantation with

      12    the device did something that transplantation

      13    without the device did.  Or you could take

      14    the route of showing that transplantation

      15    with the device or the antibody or whatever,

      16    did something compared to some other mode of

      17    transplantation.

      18              Although while the cleanest one
      19    would be one that did not involve the device

      20    since that might involve no T‑cell depletion

      21    it might be hard to ‑‑ that may or may not be

      22    doable in some circumstances.

                                                            224

       1              So I don't know if I've just made

       2    everything a lot more confusing.

       3              DR. VOSE:  Thank you.

       4              DR. SIEGEL:  I am more confused

       5    than when I started.

       6              DR. VOSE:  Dr. Auchincloss?

       7              DR. AUCHINCLOSS:  But it's a good

       8    introduction for me to make the comment that

       9    I wanted to make which will echo what I think

      10    I've said before in these kinds of settings.

      11    Before we go further with these particular

      12    questions that you put to us, my suggestion

      13    would be to you that the questions are going

      14    to lead us into strange places and not

      15    effective ones because I actually believe

      16    your entire approach to the regulation of the

      17    products that are involved in bone marrow

      18    transplantation is wrong.
      19              Why?  Because the basic issue in

      20    bone marrow transplantation has remained the

      21    same since the beginning ‑‑ engraftment,

      22    avoidance of GVH, and anti‑ tumor effect.

                                                            225

       1              But what we have heard today and

       2    continue to hear is that the ways of getting

       3    the right combinations there are going to

       4    turn out to be multiple.  Indeed, hundreds,

       5    depending on all sorts of variables ‑‑ what

       6    kind of donor, what kind of recipient do you

       7    have available?  What disease you're

       8    treating?

       9              Now, the way you're setting up to

      10    regulate these products, a T‑cell depletion

      11    device suggests that you'll need to figure

      12    out in each of these variable cases whether

      13    there's some kind of clinical efficacy

      14    benefit to the patient in terms of the

      15    treatment of the disease.

      16              In my view, that creates an

      17    incredible amount of work for you because you

      18    have so many variables that you need to keep
      19    approving a device for.  But secondly, you

      20    are in fact holding up the development of the

      21    field by not making the devices in fact

      22    widely available.  That's my personal view.

                                                            226

       1              I think the approach should not be

       2    for what are in effect devices to look for a

       3    clinical efficacy outcome you should ask the

       4    question, does the device do what the device

       5    says it does?  And as I pointed out before,

       6    if you have a device that says it depletes T

       7    cells it's totally appropriate for the FDA to

       8    ensure the public that this device does in

       9    fact deplete T cells and indeed it probably

      10    is appropriate for the FDA to insist that

      11    there be evidence that it not only depletes T

      12    cells but that it leaves in tact some stem

      13    cells that are crucial for bone marrow

      14    transplantation to succeed.  But it doesn't

      15    get you into the business of deciding in

      16    which cases is T‑cell depleted bone marrow

      17    transplantation appropriate?

      18              The clinicians in the field will
      19    figure that kind of question out.  You tell

      20    them the device can do it.  And I think that

      21    can be applied to the monoclonal antibodies

      22    as well.  Where you can set standards for

                                                            227

       1    their safety, their efficacy in doing what

       2    the antibody says it will do and let the

       3    field determine the protocols that are

       4    appropriate for each patient.

       5              DR. VOSE:  Dr. Salomon?

       6              DR. SALOMON:  Yeah, I was trying to

       7    get my hand up to say something along those

       8    lines.  I think that the idea of using

       9    historical controls in this area is really

      10    flawed, and I really hope that that doesn't

      11    come forward.  Because we've been through it

      12    in solid organ transplantation and it's

      13    really evident that this field is like where

      14    we were about 20 years ago, and that was

      15    there were dramatic center effects first of

      16    all.  And the little agreement on these very,

      17    very complex regimens both in preparative

      18    regimens, the handling of the donor inoculum,
      19    and the post‑operative regimens.  So that

      20    it's just ‑‑ I think it's an overwhelming

      21    concept to even compare one center to another

      22    center at this point.  And I think you go

                                                            228

       1    down just really a wrong alley trying to do

       2    that.  So that's one point I would like to

       3    emphasize personally.

       4              The second one is, I'm sitting

       5    here, I just think, you know, this area is so

       6    incredibly important to the history of

       7    medicine the next decade, but it's just very

       8    early in the process and I think you're way

       9    ahead of yourself demanding prospective

      10    randomized trials.  I love prospective

      11    randomized trials, don't get me wrong, but I

      12    don't see where you can do prospective

      13    randomized trials.  I think what you ought to

      14    do is a little ‑‑ here is where I come to

      15    where Dr.  Auchincloss is talking, you have

      16    to parse this out.  I mean, there are very

      17    specific problems that this field faces,

      18    chronic GVHD, acute GVHD, recurrence of,
      19    disease‑free survival, take one of those, you

      20    don't have to do, you know, a big trial.

      21    Just set an example that this product or this

      22    manipulation has an effect on one single,

                                                            229

       1    even a relatively short‑term parameter.  It

       2    reduced acute GVHD.  Okay.  Fine.  Let it go

       3    forward.

       4              You know, the details may be on a

       5    randomized prospective trial at this point.

       6              DR. AUCHINCLOSS:  Just let me be

       7    clear that that's the opposite of what I

       8    said.

       9              DR. SALOMON:  No, I don't think it

      10    is necessarily the opposite of what you said,

      11    actually, but whatever.

      12              DR. SIEGEL:  I'm sorry, reduced a

      13    single parameter compared to what?  I missed

      14    that, not historical and not randomized ‑‑

      15              DR. SALOMON:  What Dr. Auchincloss

      16    ‑‑ what he is pointing out to me is that he

      17    was saying, don't even set an outcome

      18    parameter.  He's just saying if a T‑cell
      19    device is supposed to purify T cells let it

      20    purify T cells.  And I actually have no

      21    problem with that.

      22              I was going one step further.  I

                                                            230

       1    was saying, if you feel like you have to have

       2    an outcome parameter, so this is where I felt

       3    I was segueing from you, is if you feel like

       4    you have an outcome parameter, don't take on

       5    the whole ball of wax which is what you do

       6    with a randomized prospective trial, but pick

       7    a definable outcome parameter and insist on

       8    effect on at least one outcome parameter even

       9    though the ‑‑ even though you were going to

      10    admit and all the experts will admit that the

      11    design of these trials are going to get ‑‑

      12    you know, there could be complex effects on

      13    other outcome parameters ‑‑

      14              DR. SIEGEL:  But I'm not

      15    understanding ‑‑

      16              DR. VOSE:  Compared to what?

      17              DR. SIEGEL:  ‑‑ compared to whom?

      18              DR. VOSE:  Compared to what?
      19              DR. SIEGEL:  So you're suggesting

      20    we would do the trials, but only measure one

      21    parameter, not measure the others?

      22              DR. VOSE:  But compared to what?

                                                            231

       1    That's the problem.

       2              DR. SALOMON:  Well, in that case,

       3    you can design trials if there is ‑‑ if I say

       4    I want to improve just reduce the incidence

       5    of acute Graft‑verus‑Host Disease, there I

       6    think it won't be that hard to establish a

       7    control group for that because you're only

       8    making one parameter change.

       9              Adding product X on day two.

      10              DR. O'REILLY:  I would suggest that

      11    in answer to Carole's question, I think that

      12    it's not an exact view, but in this unique

      13    circumstance, it might be a worthwhile fit.

      14    And that is if you look at experience with

      15    two antigen disparate grafts, there is a

      16    pretty sizeable amount of data on two antigen

      17    disparate unmodified grafts, and there is a

      18    cadre of individuals who have at least
      19    survived, you could take those individuals as

      20    your comparative group and ask, does the

      21    T‑cell depletion technique reduce

      22    Graft‑verus‑Host Disease in a two‑ or

                                                            232

       1    three‑antigen disparate below what is

       2    currently present for two?

       3              My reasoning would be that if you

       4    reduce it below what a two does, you

       5    certainly can make the minimal jump to say

       6    that you also hold true for three.  In other

       7    words, I'm perfectly happy to take the

       8    technique that we use right now and would be

       9    happy to do it against a one‑antigen

      10    disparate unmodified marrow graft because of

      11    the fact that I think from the same point of

      12    GVH aspects we would be able to do it.

      13              But then again, the last thing, and

      14    there I agree with ‑‑ I think actually I

      15    agree with both of you in this regard.  Is

      16    that I do think that, you know, you really

      17    can state some standards, but you are going

      18    to have to make some differences.  I think we
      19    are early, we should be doing more phase twos

      20    with targeted endpoints at this particular

      21    point and then ultimately potentially going

      22    one against the other.

                                                            233

       1              The problem is the industries may

       2    not be such as to be able to tolerate that.

       3    So then, you know, go with ‑‑

       4              DR. VOSE:  I think Dr. Anderson has

       5    been waiting a long time.

       6              DR. ANDERSON:  She wants to

       7    contribute directly to this.

       8              DR. HENSLEE‑DOWNEY:  Well, actually

       9    I think that it has to be a melding of both

      10    of these two concepts that have come forward.

      11    Now, I do like the idea that if you're going

      12    to look at a device or a drug, particularly a

      13    monoclonal antibody that's targeted against a

      14    certain cell subset that you are actually

      15    able to demonstrate and that that should be a

      16    requirement that you do what you say that

      17    this product is going to do.

      18              But I think you have to apply it
      19    then on a clinical trial to ask more

      20    questions than just one simple endpoint.

      21    Because the endpoints, you can't really just

      22    pick up one endpoint and say that's all you

                                                            234

       1    would have to show.

       2              I think that you have to decide

       3    based on the published literature using any

       4    technique, and I think that's important too.

       5    I don't think that you can say I'm going to

       6    use this technique and I'm going to only

       7    compare it to something else that looks the

       8    same.  It has to be with regards to all

       9    approaches to doing haploidentical transplant

      10    that you would develop ‑‑ I guess the term

      11    was used "targeted endpoints" and that you

      12    would have ‑‑ and maybe that's the same as

      13    saying ‑‑ stopping rules.  And that becomes

      14    quite reasonable particularly in the context

      15    of what is seen using another alternative

      16    donor.

      17              I do think eventually that the

      18    interesting question may come forward as to
      19    whether there are certain diseases that are

      20    served best by one particular donor versus

      21    another; delay in transplant is going to be a

      22    driving force always.  But we have to show

                                                            235

       1    equivalency between the different donors for

       2    people to sort of get over the reluctance to

       3    look at all donor sources perhaps so that the

       4    patient then has access to their best chance

       5    for effective, curative treatment.

       6              I think already the field defines

       7    the patient who we feel really has no

       8    opportunity for successful outcome with

       9    non‑transplant therapy and that those are the

      10    patients that go forward into alternative

      11    donor transplants.  And although there are

      12    few exceptions in unrelated donor transplant

      13    that it has been really embraced though by

      14    the field and often viewed by some to be so

      15    similar to matched‑sibling donor transplant.

      16    And those who have really gone courageously

      17    along those lines so that they can treat

      18    patients that are in the very best situation
      19    with the very best matched donor have

      20    produced those kinds of excellent outcomes

      21    that would be comparable to a matched‑sibling

      22    donor.  And we're not going to ever be able

                                                            236

       1    to do that in haploidentical transplant, or

       2    in cord blood transplant until we can all

       3    have established the techniques that give us

       4    the confidence to take this technology to

       5    those patients.

       6              But, we can still, within those

       7    worst patients, if you will, we can still

       8    develop targeted endpoints that would be

       9    expected that would make it a reasonable

      10    approach to study further.  And I think that

      11    would be the responsibility of the FDA that

      12    they would not give approval to a technology

      13    even though it was shown to perhaps target

      14    what it was supposed to target and maybe

      15    reduce GVHD if in the long run it still had

      16    all these other problems associated with it.

      17    That's why I think you have to do targeted

      18    endpoints that cross all of the major
      19    problems ‑‑ engraftment, acute and chronic

      20    GVHD, immune reconstitution, and survival.

      21              DR. VOSE:  Dr. Kurtzberg?

      22              DR. KURTZBERG:  I think one of the

                                                            237

       1    problems is you can't study these devices in

       2    a vacuum.  And the people who are ‑‑ the four

       3    or five techniques that are active with

       4    T‑cell depletion all are linked to protocols

       5    that don't just involve whatever the T‑cell

       6    depletion method is, but involve, you know,

       7    the preparative regimen and the GVH

       8    prophylaxis and all that.  So if there's a

       9    device to be tested, then that company should

      10    partner with one of the places that's already

      11    doing haploidentical transplants with some

      12    method of T‑cell depletion and either add or

      13    substitute whatever this device is in that

      14    method.  And so you could identify or they

      15    can identify five or six centers that do this

      16    and have at least expertise in it and can do

      17    what both these guys showed in terms of

      18    comparing to their own historical data, or
      19    does this work, does this work, does this

      20    work.

      21              DR. VOSE:  But the problem is what

      22    they're already doing is already

                                                            238

       1    experimental.  So you add another

       2    experimental whatever on another experimental

       3    thing.

       4              DR. KURTZBERG:  But I mean,

       5    transplantation is experimental.

       6              DR. VOSE:  I know, but now I'm

       7    speaking for them, and not for me      we get

       8    caught in the middle.

       9              DR. O'REILLY:  But, you know, I

      10    think the big problem with the experimental

      11    usually has to do not so much with whether or

      12    not it is experimental or not, but whether or

      13    not you're going to be caught by industry.

      14    So, you know, from that standpoint we're in a

      15    kind of an interesting situation because we

      16    in fact can do these trials because, you

      17    know, lectins are not patentable and in fact

      18    we can do these kinds of studies, and that's
      19    exactly the approach that we're trying to do,

      20    is to take, for example, one approach and

      21    compare it with the lectin approach at the

      22    lab level and at the clinical level, and

                                                            239

       1    then, you know, using the same kind of

       2    cytoreductive regimen.

       3              I think we can do it.  I think, you

       4    know, Jean could do it now having gone

       5    through all the pain of developing

       6    cytoreductive regimens.  You know, this is

       7    where, you know, the mutual headaches are

       8    really horrific.  But then you can say, okay,

       9    we're going to try OKT3 depletion versus, for

      10    example, what we did with T10B9 or otherwise.

      11    And you actually can do them, you know, one

      12    against the other provided you don't get

      13    caught by the vested interest of the

      14    industries that are proposing one or the

      15    other partners.

      16              DR. VOSE:  Right.

      17              DR. O'REILLY:  And I'm just lucky,

      18    because I don't have a vested interest.
      19              DR. SIEGEL:  But, Dr. O'Reilly, I

      20    wonder if I could ask you a question and this

      21    regards some of the data you presented.

      22              DR. O'REILLY:  Okay.

                                                            240

       1              DR. SIEGEL:  You showed in recent

       2    studies, if I understood correctly, a higher

       3    ‑‑ when you moved from lectin and E‑rosetting

       4    to CD34 positive selection and E‑rosetting a

       5    higher incidence of GVHD, I'm not sure I

       6    caught whether ‑‑ is the numerical T‑cell

       7    depletion significantly different between

       8    those ‑‑

       9              DR. O'REILLY:  No.  Actually what

      10    we have done is to recognize that we made

      11    targeted dosings in the trial.  And we

      12    initially had a targeted dose that the dose

      13    of T cells to be administered in the combined

      14    graft would be not higher than ten to the

      15    fifth per kilogram.  What we've done is to

      16    reduce that now to five times ten to the

      17    fourth kilogram.  And all I can say is that

      18    with the lectin graft historically we would
      19    be out to ten to the fifth realm and we saw

      20    very little.  In this circumstance we are

      21    seeing more.

      22              And I'm now in a situation where I

                                                            241

       1    would have to say, it's not just the T

       2    depletion, unfortunately, it's going to be

       3    some type of T depletion.  And the concern, I

       4    think that all of us have is we're looking at

       5    peripheral blood stem cells is that the

       6    peripheral blood pool of T cells may have a

       7    different type of population.

       8              What I would also like to know and

       9    what we are trying to get squared off would

      10    be if we did lectin E on peripheral blood

      11    stem cells that's how Aversa did his early

      12    studies and he had little or no Graft‑verus‑

      13    Host Disease.  He's only recently moved to a

      14    separate E or an E separate.

      15              You know, that's one that we're

      16    going to actually compare laboratorywise and

      17    I want to compare it clinical.

      18              DR. VOSE:  I think that is a good
      19    point though, peripheral blood is different

      20    than bone marrow and you certainly cannot

      21    compare the two in any way, shape, or form.

      22              DR. HENSLEE‑DOWNEY:  Or you should

                                                            242

       1    compare the two in a randomized trial if you

       2    want to really answer the answer.

       3              DR. VOSE:  I was speaking about

       4    historical controls.

       5              DR. HENSLEE‑DOWNEY:  Right.

       6              DR. VOSE:  That you shouldn't

       7    compare the two in historical controls.

       8              DR. HENSLEE‑DOWNEY:  Right.  No,

       9    absolutely.

      10              DR. MILLER:  Can I say something?

      11    I have sort of a radical term difference.  I

      12    agree with what they talked about that a

      13    device should do what a device is supposed to

      14    do which in this setting is decrease T cells

      15    and show equivalent engraftment.  And so my

      16    question is why are we looking at it in

      17    haploidenticals to do ‑‑ to get a ‑‑ to tell

      18    people how to get a device approved?  Why not
      19    do it in places where you actually can

      20    randomize to get those early endpoints in

      21    good risk patients ‑‑ standard risk patients,

      22    not good, but older patients over the age of

                                                            243

       1    40, and then you can get those two endpoints.

       2    And then once you got ‑‑ just like with ‑‑

       3              DR. VOSE:  Are you talking about

       4    unrelated donors?

       5              DR. MILLER:  No, no, related

       6    donors.  All you want to show is we want to

       7    show that you get decreased T cells, you

       8    decrease acute Graft‑verus‑Host Disease and

       9    you don't safety, you don't impair

      10    engraftment.

      11              DR. VOSE:  And infection.

      12              DR. MILLER:  And increase

      13    infection.  And in that setting, I mean, you

      14    can look at that.  And just like for the cell

      15    pro column for ‑‑ that we approved for

      16    peripheral blood, we did it based on the fact

      17    that it showed efficacy, and that it did what

      18    it's supposed to do and it showed relative ‑‑
      19    we didn't come out and say that the biggest

      20    burden was on ‑‑ that we worried the most

      21    about purging tumor cells out of ‑‑ I don't

      22    think that was the answer why we purged it.

                                                            244

       1    Why we approved that device is because it did

       2    what it says it was going to do.

       3              And I think that if you're going to

       4    do it, yes, I agree that T‑cell depletion is

       5    most important in the haploidentical

       6    transplants, but to actually show that the

       7    device works you don't need to do it in that.

       8    Why not say, give us a small study in

       9    patients who you can randomize and get that

      10    data and then prospectively controlled

      11    studies that will tell the field ‑‑ I mean,

      12    the field will determine ‑‑ the experts of

      13    the field will determine how to use it after

      14    it gets out there in the patients that you

      15    cannot randomize.

      16              DR. SIEGEL:  Dr. Miller, just for

      17    clarification though, you're using some of

      18    the same language Dr. Auchincloss did
      19    regarding devices doing what they're supposed

      20    to do.  But if I understand ‑‑ although he

      21    was suggesting that if they deplete the T

      22    cells that's doing what they're supposed to

                                                            245

       1    do and engraft.  You're suggesting also

       2    though in such a study you could and also

       3    should look for decreasing Graft‑ verus‑Host

       4    Disease as well.

       5              DR. MILLER:  Yes.  Or just a

       6    safety.  I mean, you want to show safety and

       7    efficacy and you could say that the efficacy

       8    is decreasing two and a half logs of T cells,

       9    no different than decreasing two and a half

      10    logs of multiple myeloma cells which is what

      11    we had as a standard.  But then you have to

      12    somehow show safety.  And the safety in this

      13    is since you're working with a hematopoietic

      14    cell process, what we've said the safety

      15    issue was is that grafts are enabled to

      16    engraft.

      17              DR. SIEGEL:  There's an importance

      18    difference though between asking for a
      19    decrease of two and a half logs of T cells

      20    they're asking for a decrease in Graft‑

      21    verus‑Host Disease.

      22              The logic of the committee in the

                                                            246

       1    tumor was in part that it was several years

       2    of follow up to see whether tumor cell

       3    depletion mattered and that in fact the

       4    interactions with chemotherapy regimes are

       5    something that made that somewhat not

       6    practical.  Whereas if you're getting

       7    engraftment data and you're getting infection

       8    data, there's not that feasibility issue of

       9    getting Graft‑verus‑Host Disease data.

      10              DR. HENSLEE‑DOWNEY:  And, Carole, I

      11    would be concerned that if you test it in a

      12    matched‑sibling donor setting that doesn't

      13    mean that it's going to work in a

      14    haploidentical setting.  And a lot of people

      15    would come to the table and argue you don't

      16    need to demonstrate to anyone that you can

      17    develop a technology that will do T‑cell

      18    depletion in the matched‑sibling donor
      19    setting.  Because, you know, then you beg the

      20    whole question about whether T‑cell depletion

      21    should be done in the matched‑sibling donor.

      22    And that can be argued where it is being

                                                            247

       1    argued.  But showing that a device produces

       2    the T‑cell depletion that can result in

       3    successful engraftment with a matched‑sibling

       4    donor and control Graft‑verus‑Host Disease

       5    means nothing when you come to haploidentical

       6    transplant.

       7              I had no idea whether it will work.

       8              DR. MILLER:  But we're testing what

       9    a device what something does and then what

      10    they do ‑‑ is phase two studies after ‑‑

      11              DR. O'REILLY:  Carole, my read of

      12    it is that actually, you're correct.  I would

      13    just sort of two caveats.  One to you and one

      14    to you.  The one to you is that, yes, it

      15    should do what it's supposed to do.  But the

      16    first one to do that was, for example, Dr.

      17    Bocci ‑‑ in Genoa.  And he set back the

      18    T‑cell depletion world by about three or four
      19    years in Europe and in this country because

      20    he did T‑cell depletion using his particular

      21    garden variety monoclonal antibody generated

      22    in Genoa.  And it turned out that it did

                                                            248

       1    deplete some T cells.  The problem was that

       2    it did not in any way affect graft versus

       3    host disease and 11 out of the first 13

       4    patients that he transplanted relapsed with

       5    disease within six months.

       6              Now, he was relatively smart and he

       7    recognized that he hadn't picked out all T

       8    cells, he had actually probably picked out

       9    some sort of regulatory cells.  But from that

      10    time on that was the basis of the IBMTR

      11    saying that the instance of relapse in acute

      12    leukemias is higher in T‑cell depletion.  And

      13    that went on for years until enough data were

      14    accumulated to say all of a sudden, it is

      15    not.

      16              Now, Monmouth was the guy who

      17    recorded ‑‑ Monmouth is from that center and

      18    he just doesn't want to hear that, but that
      19    is it.  Their GVH was not altered.  So I

      20    would suggest that one, you have to have a

      21    biological parameter, so, so if you do the T‑

      22    depletion, you have to show that numerically.

                                                            249

       1    But I think you have to correlate it with the

       2    absence of GVH where the reduction in GVH

       3    because that's why you're doing T‑cell

       4    depletion in the first place.

       5              The second part, though is yours.

       6    Now, I concur now randomized trials has to be

       7    done, but Essie can tell you this, one of the

       8    things that's most discouraging about this is

       9    when we set up that kind of a trial

      10    specifically for a grant in 1994.  No matter

      11    what we do in offering that trial, discussing

      12    that trial, et cetera, patients come to

      13    Memorial because they wanted T‑depleted

      14    graft.  If they don't want a T‑ depleted

      15    graft, they're going to go somewhere else.

      16    But it has been almost unbelievably difficult

      17    to accrue patients in that randomized trial

      18    because it is in a, you know, for those who
      19    believe ‑‑ you know, for those who don't

      20    believe, no explanation is possible; and for

      21    those who believe, no explanation is

      22    necessary.

                                                            250

       1              I mean, it really comes down to

       2    that.  And we have been frustrated by that to

       3    the point where, you know, I proposed this in

       4    a program project grant and my group is

       5    saying, we can't do it.  And I say, but if we

       6    don't do it, you know, we uniquely must do

       7    it, if we don't do it it's a problem.  The

       8    fact is, accrual‑wise we may never be able to

       9    pull it off.

      10              DR. MILLER:  But a company, if they

      11    want to get their device approved they'll

      12    have the wherewithal to have enough centers

      13    to do that.  I mean, it's no different than a

      14    drug such as, you know, 4HC, that, you know,

      15    always you need to have something to compare

      16    it against, how do you ‑‑ you know, people

      17    who either believe or don't believe, well,

      18    you know, the bottom line is, we don't know
      19    the answer and so you've to show it.  And so

      20    that's why I'm saying, if there was a group

      21    that it could be done with, even though it's

      22    not that easy, why not do it in that group?

                                                            251

       1              DR. O'REILLY:  Well, yeah, I ‑‑

       2              DR. VOSE:  I think you can

       3    reasonably ‑‑

       4              DR. MILLER:  I think you can very

       5    easily randomize people who are matched

       6    siblings ‑‑

       7              DR. VOSE:  But I have to agree with

       8    Jean, I don't think that doing that trial in

       9    a matched sibling donor means anything to

      10    using it in a different situation.  Maybe a

      11    closer situation as unrelated donor that's

      12    fully matched would be a possibility.  I

      13    think that's a possibility, but I don't think

      14    the related would be good.

      15              DR. O'REILLY:  One of those trial

      16    is ongoing.

      17              DR. VOSE:  Right.  That actually

      18    was my other question.  What's going on with
      19    that it's an NHBL trial right?

      20              DR. O'REILLY:  It's accruing.  You

      21    know, in large numbers.  It's supposed to be

      22    finished in what, another 18 months?

                                                            252

       1              DR. PAPADOPOULOS:  It's behind in

       2    accrual.

       3              DR. VOSE:  So it's behind in

       4    accrual, but there are approximately 300 or

       5    so patients accrued out of 560, I think.

       6              DR. PAPADOPOULOS:  Right.

       7              DR. VOSE:  That's nothing ‑‑

       8              DR. KURTZBERG:  Well, I know they

       9    just cut it back because it was going to take

      10    too long to form something.

      11              DR. VOSE:  They may have cut back

      12    the total ‑‑

      13              DR. MILLER:  And that has two

      14    different types of T‑cell depletion right

      15    there elutriation and T10B9.

      16              DR. KURTZBERG:  But, again, those

      17    are packaged deals.

      18              DR. VOSE:  Right.
      19              DR. KURTZBERG:  The prep regimen

      20    for the conventional non‑T‑depleted arm is

      21    completely different than the T10B9 ‑‑

      22              DR. VOSE:  Right.

                                                            253

       1              DR. KURTZBERG:  ‑‑ which is

       2    completely different than the elutriation.

       3    And, in fact, there are two T10B9 prep

       4    regimens.

       5              DR. VOSE:  That's because none of

       6    us can agree on anything.   Dr. Anderson?

       7              DR. ANDERSON:  Yes, I keep

       8    relinquishing my spot because it's

       9    fascinating listening to everybody talk.

      10    Basically all the points I wanted to make

      11    have already been made.  So let me just make

      12    a brief summary.  What I had wanted to point

      13    out was basically what Hugh said, but from a

      14    slightly different perspective.  And the

      15    perspective is as a person who deals with

      16    bone marrow transplanters, but is not a bone

      17    marrow transplanter.

      18              In my experience from ten years
      19    ago, Rich, when you and I worked together to

      20    the present is every time you sit down with

      21    someone in bone marrow transplant and start

      22    to go over the real results of somebody's

                                                            254

       1    data, and you say, well, what about such and

       2    such, it's because they varied this, they

       3    varied ‑‑ there are 25 different variables

       4    and so it's just ‑‑ it's fuzzy.  This is very

       5    early in a very complex field.  And since all

       6    the points bearing on this have already been

       7    made, let me just emphasize in a slightly

       8    different way what you said, and that is what

       9    I would hope that the FDA takes as one of its

      10    primary criterion dealing with this, clearly

      11    the safety of the public, but basically what

      12    can the FDA do to help the investigators

      13    further the field?  That that should be the

      14    primary objective.  Clearly safety is ‑‑

      15    that's a non‑issue, we all agree with that.

      16              But there is the potential danger

      17    because this field is so complex, because

      18    each investigator does things their own way,
      19    and Rich has made the point I was going to

      20    make which is that how can you accrue a large

      21    number of patients in any kind of a

      22    randomized trial when people go to people

                                                            255

       1    because they do something and get away.  This

       2    is a field where you can't really do that.

       3    It's not like drugs where you can set up 20

       4    institutions and they all agree, this is the

       5    dose they're going to give, and if the age is

       6    this and the symptoms are that.

       7              So a plea to the FDA to think in

       8    large measure what position can the FDA take

       9    which helps the investigators answer the

      10    questions.

      11              DR. SIEGEL:  I certainly agree

      12    that's an important goal, but in some sense,

      13    implicit in your preamble is an answer I

      14    think different from the one you're implying.

      15              DR. ANDERSON:  Okay.

      16              DR. SIEGEL:  Because if I might

      17    rephrase what you just said to me ‑‑

      18              DR. ANDERSON:  Sure.  Okay.
      19              DR. SIEGEL:  ‑‑ is ‑‑ what I just

      20    heard you say at least, is that having talked

      21    to bone marrow transplanters over the years,

      22    there are so many variables in comparing any

                                                            256

       1    therapy that it's very difficult to make any

       2    conclusions regarding how to compare those

       3    therapies.  But then you're suggesting to

       4    advance the field we should, rather than move

       5    into a situation where were we have

       6    controlled clinical trials with a single

       7    variable, rather than suggesting that, you're

       8    suggesting that we should continue that way

       9    and ‑‑

      10              DR. ANDERSON:  No, no, I didn't.

      11    If that's the impression I gave I shouldn't

      12    have cut it so short.  No, no, it was simply

      13    to try to point out the situation that it is

      14    going to be much more difficult in this field

      15    than in many fields in order to do the best

      16    type of clinical trials and not to be rigid

      17    in terms of the approach.  That's all I meant

      18    to say.
      19              DR. KURTZBERG:  I also think it's

      20    too early to just say there's going to be one

      21    answer.  And each one of these methods has

      22    their own challenges and none of them are

                                                            257

       1    good enough to give up the other ones, and

       2    like Jean said, there may be certain diseases

       3    ‑‑ you know, CML may need more cells and cord

       4    blood may never work, but, you know, some

       5    other disease may be fine with fewer cells

       6    and may need more T cells and so T‑ cell

       7    depletion won't work.  And we're just not

       8    there.  So each method has its own

       9    challenges.  And if the devices can fit into

      10    addressing what those challenges are, then it

      11    makes sense to test some of those methods.

      12              DR. VOSE:  I think transplantation

      13    we all know is an art and a science.  And

      14    those little final points are things that we

      15    need to work out.  But you have to think

      16    about it from a manufacturer and from FDA's

      17    standpoint they're asking kind of different

      18    questions.
      19              DR. KURTZBERG:  Yeah, but the

      20    transplants have spent 20 years figuring out

      21    how to get where they got with a certain

      22    method, then it's not unreasonable to ‑‑ you

                                                            258

       1    know, you can't just drop a device in and all

       2    of a sudden assume that's going to solve

       3    everything and then work with everything.

       4              DR. VOSE:  No, I don't think

       5    anybody thinks that.

       6              DR. O'REILLY:  I would just ‑‑ you

       7    know, I don't feel that the transplanters

       8    also have to be particularly defensive

       9    because the actual result is a pretty good

      10    one to say the least.  And I think that

      11    certainly for diseases like CML, it's better

      12    than around.  But I think that what was

      13    stated before though is that the devices fit

      14    within, in fact, the package.  That a

      15    T‑depleted graft is more sensitive to host

      16    resistance than an unmodified graft.  That

      17    the critical facilitator cell that we can

      18    talk about is in fact an alloreactive T cell
      19    that's in the graft.  That was shown in the

      20    1970s by Bob Lowenberg where he just took

      21    early fetal liver cells and shot them in and

      22    if you even add a minuscule number of T cells

                                                            259

       1    from the thymus you massively potentiate the

       2    engraftment process.

       3              So removing T cells it was not

       4    surprising that you would have a problem of

       5    graft failure.  And the fact of the matter is

       6    with modifications in terms of how one does

       7    these, in fact, you can overcome that.

       8              So, therefore, I think it is going

       9    to be a package, it's going to be a package

      10    of cytoreduction plus a T‑depletion

      11    technique, but then at that point, you know,

      12    the way ‑‑ for example, the NHLBI trial was

      13    set up, that was set up with a reasonable

      14    mode.  Because what you're really asking is

      15    fundamentally, can a T‑cell depletion

      16    technique achieve engraftment, reduce

      17    Graft‑verus‑Host Disease and potentially as a

      18    result of that lead to a reduction in
      19    non‑leukemic mortality and potentially in

      20    improved long‑term survival.  That's what

      21    they're asking.

      22              Now, the second thing I would say

                                                            260

       1    from the FDA point which could be helped ‑‑

       2    could help us enormously in the field and

       3    also could help the real aspect of what

       4    happens with the industrial folks is that we

       5    as investigators look at a particular

       6    procedure, or a particular device and we say,

       7    all right, let's say I take it in the lab and

       8    I look at it, and I say, God, this device

       9    does a really good job.  It allows me to

      10    concentrate progenitor cells and removes T

      11    cells and as far as I can see it removes

      12    alloreactive T cells.  I want to go at it.

      13              And the manufacturer says, well,

      14    we'd love to give you these devices, but the

      15    problem is we're going to go out of business

      16    because our burn rate is so high.  Okay.  And

      17    we as institutions say, well, we would love

      18    to just go ahead with this and not worry
      19    about that, but we have no mechanism to pay.

      20              Now, one of the things the FDA has

      21    done for several devices, and I think if they

      22    could make that almost as a sort of a general

                                                            261

       1    approach is that if you have preclinical

       2    evidences that in fact these things do what

       3    they say they do on a reproducible level and

       4    they want to now go into clinical trials.  At

       5    least the clinical trials can be done in a

       6    cost‑recovery mode.  If that could be done

       7    initially rather than sort of somewhere down

       8    the line, that's going to be a huge boost to

       9    these kinds of trials.

      10              The second aspect of it is if you

      11    don't have the package recognizing the

      12    biology of these different types of

      13    transplants, okay, you can probably get, you

      14    know, quite literally, randomized trials

      15    done.  But they would have to be in a context

      16    of a package of a cytoreductive regimen plus.

      17              DR. HENSLEE‑DOWNEY:  Although I

      18    think it's hard to talk about cost recovery
      19    in an era of capitation because you may be

      20    shifting costs and therefore you might still

      21    be able to say you can recover the costs, but

      22    you can't directly recover ‑‑

                                                            262

       1              DR. VOSE:  You can't bill the

       2    patient for that current thing that's in the

       3    package, and so basically you're still ‑‑

       4              DR. HENSLEE‑DOWNEY:  No ‑‑

       5              DR. O'REILLY:  No, no, but they

       6    can.  If they allow you to bill the patient

       7    for cost ‑‑

       8              DR. VOSE:  But ‑‑

       9              DR. O'REILLY:  ‑‑ recovery ‑‑

      10              DR. VOSE:  ‑‑ most of them you

      11    can't bill the patient.

      12              DR. KURTZBERG:  But even if you do

      13    bill the patient, if you're getting $100,000

      14    and it's ‑‑

      15              DR. VOSE:  Right.

      16              DR. KURTZBERG:  ‑‑ and it only can

      17    go so many places whether you bill or not.

      18              DR. VOSE:  Right.  If it's just a
      19    package deal, a package transplant ‑‑

      20              DR. SIEGEL:  I should point out

      21    cost recovery is covered by our laws and our

      22    regulations and is as with many of the things

                                                            263

       1    we do somewhat subject to what our policy and

       2    scientific judgment is and somewhat dictated

       3    by what the laws of the country are which we

       4    must uphold.  But it applies different ‑‑

       5    your comment mentioned devices and it does

       6    apply differently for devices.  There's much

       7    more leeway to the Agency in allowing cost

       8    recovery for a device early in its

       9    development in an experimental stage than

      10    would be for if we're talking about, say, a

      11    growth factor or an antibody that is not part

      12    of a device, but is being sold as a drug for

      13    example.

      14              Although in those cases cost

      15    recovery is possible.  It requires additional

      16    showings as you implied in terms of clinical

      17    utility in addition to financial hardship

      18    issues.
      19              DR. KURTZBERG:  But that's going to

      20    be a Catch 22 because if you've got a

      21    capitated rate and your hospital is already

      22    unhappy with what you're doing and you put in

                                                            264

       1    something that's more money, it's going to

       2    take out of their ‑‑ it's coming out of the

       3    same pot, it's not going to be popular.

       4              DR. VOSE:  No, it's not going to

       5    work.

       6              DR. SIEGEL:  Right.  Well, in that

       7    regard, you know, one could argue, although

       8    this isn't where we're going, but a lower FDA

       9    requirement for approval may not further the

      10    field by ‑‑

      11              DR. SALOMON:  The thing you have to

      12    remember in this capitation argument is that

      13    you have to look at then long‑term outcomes.

      14    In other words, if I have a patient with

      15    leukemia and I cure the leukemia and then I

      16    get a relapse or I get a bad GVHD it costs me

      17    more per patient to manage that than if I've

      18    reduced the costs.  So, yeah, it might cost
      19    me $10,000 more because of my device or drug,

      20    but if I reduce the complications in one in

      21    other vocal points, I significantly reduce

      22    the overall cost.  So that's the thing you've

                                                            265

       1    got to keep in mind.

       2              DR. KURTZBERG:  But if you're a

       3    transplant referral center and all your

       4    hospital is looking at is their piece of the

       5    pie, they don't care what happens to that

       6    patient a year later, because it's not going

       7    to be coming out of their pocket ‑‑

       8              DR. SALOMON:  But a lot of the

       9    money is ‑‑

      10              DR. KURTZBERG:  I'm not saying

      11    that's right, but that's what is happening.

      12              DR. SALOMON:  I understand, but a

      13    lot of the money now is coming from managed

      14    care organizations who have a stake in the

      15    patient from the beginning to the end.  Your

      16    hospital may be in the middle of it, but ‑‑

      17              DR. VOSE:  Most of the large

      18    transplant centers that's not how it happens
      19    anymore.  The patients come there and they

      20    get $100,000 to do a transplant and after the

      21    patient goes away, that's it.

      22              DR. AUCHINCLOSS:  Jay, I think that

                                                            266

       1    was clever.  The notion that the FDA is

       2    involved in it has actually hastened the

       3    field by insisting on companies performing

       4    trials as cover, but I don't believe it.

       5              DR. SIEGEL:  Pardon?

       6              DR. AUCHINCLOSS:  But I don't

       7    believe it.

       8              DR. SIEGEL:  What did you say?

       9              DR. AUCHINCLOSS:  The notion that

      10    you're involvement was actually going to

      11    hasten the performance of trials and

      12    introduction of all of these by somehow

      13    forcing the companies to perform them and

      14    provide the equipment for free et cetera is

      15    cute, I like it, but I don't actually believe

      16    it.

      17              I mean, but that wasn't going to be

      18    main ‑‑
      19              DR. SIEGEL:  Well, I don't know if

      20    it's true here or not, but a good number of

      21    important clinical trial are funded by

      22    pharmaceutical companies.

                                                            267

       1              DR. AUCHINCLOSS:  There's no

       2    question about it.

       3              DR. SIEGEL:  A significant number

       4    of them are funded because they're necessary

       5    to meet regulatory requirements ‑‑

       6              DR. AUCHINCLOSS:  And that's true

       7    too.

       8              DR. SIEGEL:  ‑‑ and one can ‑‑ one

       9    needs to look carefully when one suggests

      10    lowering regulatory requirements at the

      11    possibility that if trials ‑‑ if the

      12    pharmaceutical companies or the device

      13    manufacturers are not required to do the

      14    trial in order to market and promote a device

      15    the trial may be less likely to get done

      16    rather than more likely to get done, and, you

      17    know, I don't know that we should argue that

      18    issue here, but I wouldn't dismiss it out of
      19    hand.

      20              DR. AUCHINCLOSS:  I certainly agree

      21    with you and we've had that discussion

      22    previously about some of the other products,

                                                            268

       1    as you know.  Which things should we use your

       2    leverage for, et cetera?  I mean, the point

       3    is potentially valid.

       4              But let me get back ‑‑ I did want

       5    to make one clarification that I think I've

       6    been sort of ‑‑ my comments have been used to

       7    sort of suggest that I don't believe in

       8    clinical trials.  I mean, that is not the

       9    point that I'm making.

      10              I want you to do lots of trials,

      11    thousands of trials, you've got lots of

      12    things to figure out.  The issue is not,

      13    should we have clinical trials, the issue is,

      14    what trials are appreciate to get product

      15    approval?  And that's quite different.

      16              And I actually think that the

      17    T‑cell depletion device example is perfect at

      18    demonstrating how you can misuse product
      19    approval and get the wrong clinical trial for

      20    exactly the reason that Jean suggested.  If I

      21    wanted to design a trial that showed T‑cell

      22    depletion caused less GVH, I know I could do

                                                            269

       1    it.  It would probably be one antigen match

       2    and it would be a non‑cancer situation.  I'd

       3    work out the variables where I know I could

       4    show a reduction in Graft‑verus‑ Host

       5    Disease.  And once I had the product

       6    approved, I'd have the product approved.  But

       7    the results of that study would be completely

       8    meaningless for where you really need T‑cell

       9    depletion which, of course, is in the haplo

      10    transplant.

      11              DR. SALOMON:  Yeah, but that was

      12    your point.  Your point was that if it

      13    worked, and it did it, and you proved it in

      14    your trial, which is my point, pick a parsed

      15    outcome and then establish it, then let the

      16    field ‑‑ the experts in the field segue it

      17    into other trials and be responsible for the

      18    results.
      19              DR. AUCHINCLOSS:  The second part

      20    of what you said is my point.  Let the

      21    experts in the field figure it out.  But let

      22    me just keep my point ‑‑ my point is my

                                                            270

       1    point.  My point is the device should be

       2    licensed on the basis of it doing what the

       3    says the does.

       4              DR. VOSE:  But it needs to do it in

       5    a situation where it makes some relevance or

       6    ‑‑

       7              DR. SALOMON:  I disagree with you

       8    ‑‑ I'm sorry.  I can take ‑‑ I can go into

       9    the lab and separate T cells in 200 bone

      10    marrow preparations and show that the device

      11    does what it does.  And that's all you're

      12    expecting for approval, then I don't buy it.

      13              DR. VOSE:  No, I think that's

      14    wrong.  And you need to show some benefit for

      15    what you're doing or it's meaningless.  I'm

      16    sorry.  It has to have some benefit.

      17              DR. MILLER:  You need to show some

      18    benefit, but not the maximal benefit.
      19              DR. VOSE:  Well, no, I'm not ‑‑

      20              DR. MILLER:  I mean, you can show

      21    in a group of patients you can show that

      22    there's a benefit that can be measured

                                                            271

       1    compared to control, but it's not in the same

       2    league as the number and the benefit that you

       3    expect in the patients that are at the

       4    highest risk.

       5              But you're going to be in HLA

       6    identical, or one anti mismatch or some good

       7    group, you're going to be able to show that

       8    there was a basis for really taking it in to

       9    what patient population you are really

      10    concerned about with this device as compared

      11    to OKT3 which is what you're using now.  Just

      12    similar things in the good risk patients and

      13    now you can take it and then do to phase II

      14    study or, you know, the study that you want

      15    to do in your patients, with the only

      16    stopping rules and the very, very high risk

      17    patients, but at least you know are very good

      18    data on what it does to T cells, CFUGM, CD34
      19    cells and early evidence of, you know, other

      20    immune functions even in those patient

      21    populations.

      22              Yes, it's going to be different

                                                            272

       1    than your patients, but it still is going to

       2    be able to help you build on it, and you're

       3    going to be able to compare it to something

       4    else.  These patients are very complicated.

       5    The preparative regimens are very

       6    complicated.  So in the absence of doing

       7    something where you're comparing one to

       8    another we'll never every know what these

       9    devices do.

      10              DR. HENSLEE‑DOWNEY:  I guess my

      11    concern is that it's a huge issue that might

      12    be handled as a silent nuance.  And so that

      13    the unsuspected or unexpected population are

      14    told, yes, look how beautifully this worked.

      15    I mean, I've seen this too many times and no

      16    one is telling them the caveats underneath

      17    that.  And so patients sort of blindly go

      18    into a trial believing that this is what
      19    they're going to get.  And yet you change the

      20    stem cell source.  It's a huge difference.

      21              DR. MILLER:  Right now you're doing

      22    it with OKT3 where you don't even have any of

                                                            273

       1    that data on what it does compared to a

       2    randomized control group, so you're making

       3    that leap of faith one step better to the

       4    patient saying, okay, I have no data what

       5    this does in vitro, but you're a very

       6    high‑risk patient, I'm going to use it.  And

       7    so why not do something you actually have the

       8    data on before you do the high‑risk patients.

       9              DR. VOSE:  Well, you have to do it

      10    in a patient population that has at least

      11    some of the same problems that we're talking

      12    about.

      13              DR. MILLER:  Well, GVHD ‑‑ you

      14    know, you can get stage four with GVHD in a

      15    sibling ‑‑

      16              DR. O'REILLY:  But, Carole ‑‑

      17              DR. VOSE:  But it's different.  I

      18    mean, the percentage is much different, and
      19    the engraftment is much different.

      20              DR. HENSLEE‑DOWNEY:  And the

      21    management.

      22              DR. VOSE:  Management is much

                                                            274

       1    different.  Yeah.

       2              DR. O'REILLY:  But I would also

       3    note, it is not so much of an art to, you

       4    know, the devices we're talking about, for

       5    example, anything that's entered into

       6    clinical trials at our shop.  The in vitro

       7    data has been, you know, really put through a

       8    lot before we even introduce it.  My readout

       9    when we did those comparative trials was that

      10    I ‑‑ you know, did I think that lectin

      11    agglutination and E‑rosette depletion in 1980

      12    was going to last very long in that time?

      13    No, I didn't because the thought, you know,

      14    there's going to be much more sophisticated

      15    programs.  At that time we didn't even have

      16    monochromals against T cells.  But the

      17    problem ‑‑ the issue was that it was very

      18    effective in terms of T‑cell depletion and we
      19    could show it.  All we basically said was,

      20    we'll take anything that can give us

      21    comparable levels of T‑cell depletion and we

      22    could consider testing it because that

                                                            275

       1    technique has been tested in animals, in

       2    primates.  We did all of that before we ever

       3    did the first SCID kid.  And I think that we

       4    do have, you know, in this sort of a stepwise

       5    approach where you have several standard

       6    approaches based on in vitro in pre‑clinical

       7    studies that we developed that other groups

       8    have developed in concert with industry

       9    before they're introduced.  So it's not that

      10    OKT3 doesn't, but it does.  You know, T10B9

      11    does.  There's a lot of studies that will

      12    show that these kinds of agents will in fact

      13    deplete T cells and we do ongoing studies of

      14    those even before we introduce them.

      15              I think the issue though ‑‑ I'm

      16    switching on this score though ‑‑ is that

      17    some aspect of a biological parameter I think

      18    both you guys are saying the same thing, and
      19    there I do disagree with you. I think that

      20    you want something that will deplete, yes,

      21    but you want to have something where the

      22    depletion is correlated with a true reduction

                                                            276

       1    in GVH.

       2              My real problem is that I've seen

       3    people who deplete quote/unquote T cells.

       4    But, in fact, do not in any way deplete

       5    Graft‑verus‑Host Disease.  And I don't think

       6    that's T‑cell depletion, or I don't think

       7    it's allo T‑cell depletion as opposed ‑‑ and

       8    I do think that that's a reasonable thing we

       9    have to ‑‑

      10              DR. VOSE:  I don't think it's

      11    necessary to show an improvement in overall

      12    survival, for example, but I do think you

      13    need to show an improvement in

      14    Graft‑verus‑Host Disease that that will ‑‑

      15              DR. O'REILLY:  But you would not ‑‑

      16              DR. VOSE:  ‑‑ at least be a better

      17    quality of life for the patient, you know,

      18    something like that.
      19              DR. O'REILLY:  But all I would

      20    really say is that I think one of the areas

      21    that we can use as a marker that I think is

      22    really useful would be a reduction in

                                                            277

       1    transplant‑associated mortality.

       2              DR. VOSE:  Sure.

       3              DR. O'REILLY:  So, namely GVH

       4    that's your target.  But if at the same time

       5    as when we started, you know, you come up

       6    with a high level of graft failure that's not

       7    helpful.  So you want, you know, an

       8    acceptable level of graft failure or graft

       9    failure no greater than unmodified grafts

      10    coupled with a reduction in GVH and your

      11    expectation would be that that would be

      12    associated with a reduction in

      13    transplant‑related mortality.  It would not

      14    be something for disease, but I would suggest

      15    that for several of these diseases adding in

      16    the issue of relapse gets pretty dicey.

      17              DR. VOSE:  Right.  That's what I'm

      18    saying.  I don't think you need to size or
      19    power a study to say that they have to have

      20    an improvement in overall survival.  An

      21    equivalency of that would be adequate, I

      22    think.  Jean.

                                                            278

       1              DR. HENSLEE‑DOWNEY:  I think

       2    another way to look at it is if you are a

       3    company trying to produce a monoclonal

       4    antibody or some molecule that's going to

       5    help transplanters deal with

       6    histoincompatibility or whether you're using

       7    some cell sorter device to do T‑ cell

       8    depletion or whatever.  The driving force is

       9    haploidentical transplant.  Because if a

      10    company is going to invest a large amount of

      11    money into trying to produce something that

      12    they can put on the market, it's because it's

      13    going to be used a lot, and that's the only

      14    reason.  So if you do this for a matched

      15    sibling donor, you'll never even recoup your

      16    R&D costs.  You have to do it because now

      17    you're going to really create new

      18    opportunities to do transplants.  And with
      19    haploidentical transplants, that's the beauty

      20    that really everybody has a donor and they

      21    immediately have a donor.  So now you've

      22    created complete universal access to

                                                            279

       1    allogeneic transplant.

       2              Now, that would drive you to expend

       3    money to develop that technology.

       4              DR. VOSE:  But I think the question

       5    is, can you do a study that's not necessarily

       6    in haplos and then perhaps in ‑‑

       7              DR. HENSLEE‑DOWNEY:  No, because if

       8    it doesn't have any meaning ‑‑

       9              DR. VOSE:  No, I'm saying ‑‑

      10              DR. HENSLEE‑DOWNEY:  ‑‑ I mean,

      11    that's what you would ‑‑ you have to develop

      12    ‑‑

      13              DR. VOSE:  ‑‑ for us to use that

      14    device for that antibody than to further

      15    modify it and to do it in appropriate trials

      16    once it's been looked at in perhaps a less

      17    high‑risk population.  I'm not saying for it

      18    to be generalized approved.
      19              DR. O'REILLY:  Yeah, I would

      20    honestly say from the standpoint of the issue

      21    of GVH.  You know, certainly we've done it

      22    without prophylaxis, so I can say that.  I

                                                            280

       1    mean, we saw a dramatic reduction in GVH in

       2    the haplotype disparates, that's actually how

       3    we started.  But the fact of the matter is,

       4    in the leukemic circumstance we went back to

       5    the drawing boards for matches.  There was no

       6    doubt it reduced GVH, and then we got over

       7    the issue of rejection.  Once we go over

       8    that, the principles learned there could be

       9    then applied to the broader realm.

      10              I don't know that we couldn't do a

      11    stepwise one to two antigen disparate graft,

      12    for example, that's where you're at as well;

      13    right?  One two antigen disparate, you know,

      14    you prefer not to do a three even in the

      15    absence of the historical.  I don't think

      16    it's completely apples and oranges.  I think

      17    you can make it stepwise.

      18              DR. MILLER:  But we still have real
      19    problems in allogeneic sibling donor

      20    transplants, especially if people want to go

      21    to peripheral blood stem cells.  I mean,

      22    you're looking at a much greater incidence of

                                                            281

       1    acute ‑‑ I mean, of chronic Graft‑verus‑Host

       2    Disease and no decrease.  So, I mean, there's

       3    a patient population where you ‑‑ you know,

       4    where the standard has a pretty high

       5    incidence of chronic Graft‑verus‑Host Disease

       6    and a reasonable incidence of acute Graft‑

       7    verus‑Host Disease that we don't think ‑‑ you

       8    know, that a lot of people are uncomfortable

       9    ‑‑ may be uncomfortable starting to use

      10    peripheral blood progenitors because we don't

      11    know if it's going to increase the up front

      12    mortality.  That's a place where why not do

      13    the study in that patient population.

      14    There's a question to be asked as we don't

      15    think we have all the answers.

      16              The second thing that makes me

      17    think of why we can't look at this T‑cell

      18    depletion in those patients is the data that
      19    you showed, Rick, looking at your data as the

      20    78 or 80 percent in the first remission ‑‑

      21    that's T‑cell depletion showing very, very

      22    good data, I mean, in a single institution.

                                                            282

       1    But it would be nice even in the good risks

       2    to get that type of data.  And the only way

       3    you're ever going to prove and have these

       4    devices available is by showing that it

       5    works.  And I think if you really want to

       6    answer the question, do these questions work

       7    in a randomized trial, you get the transplant

       8    and say, okay, we'll do the trial, maybe we

       9    don't ‑‑ you know, I believe in T‑ cell

      10    depletion, or I don't believe in T‑cell

      11    depletion, but the only way you're ever

      12    actually going to get the device out there so

      13    that you could ‑‑ if you wanted to keep using

      14    T10B9, well, you can't now, because you can't

      15    get it.  You'd really probably like to be

      16    back to doing it.

      17              If you're told the only way you can

      18    get T10B9 with which you've got great data is
      19    to do this trial, you would probably do the

      20    trial.  Right?

      21              DR. HENSLEE‑DOWNEY:  I'm just

      22    saying that the real home run though would be

                                                            283

       1    to do the trial in haploidentical transplant.

       2              DR. MILLER:  There's no control.

       3    But how?  How can we do that?  There's no

       4    control.

       5              DR. HENSLEE‑DOWNEY:  But then you

       6    don't have to have ‑‑

       7              DR. VOSE:  But folks, I think we're

       8    missing the ‑‑

       9              DR. HENSLEE‑DOWNEY:  ‑‑ the

      10    randomized.

      11              DR. VOSE:  But there's no adequate

      12    historical control.

      13              DR. PAPADOPOULOS:  But, Julie, I

      14    mean, we're talking about haplos as though

      15    they can be done and they're done easily and

      16    we just ‑‑

      17              DR. VOSE:  No.  No.

      18              DR. PAPADOPOULOS:  ‑‑ compare two
      19    approaches and see if one is better than the

      20    other.  The fact that they're being done at

      21    all, mind you, by a relatively small number

      22    of centers compared to regular allo bone

                                                            284

       1    marrow, or peripheral blood stem cells from a

       2    matched sibs or unrelated, it's short of a

       3    miracle, basically, the fact that you can do

       4    this against such HLA barriers.  And we're

       5    still way down low on the learning curve.

       6    There's a lot of room for improvement in

       7    these kinds of transplants.  See, I agree

       8    with Jean, I think the place where a sponsor

       9    could market this type of a device, and agent

      10    to reduce Graft‑verus‑Host Disease would be

      11    in the haploidentical transplants.

      12              I think randomized trials comparing

      13    conventional to T‑cell depleted is much more

      14    of a scientific question for the scientific

      15    community and I'm not sure sponsors are

      16    really going to want to get into that because

      17    there is such a bias in the transplant

      18    community for one versus the other.
      19              DR. O'REILLY:  In the matched.

      20              DR. PAPADOPOULOS:  In the matched

      21    setting that it would be a very difficult

      22    trial to perform.

                                                            285

       1              DR. SALOMON:  I think the thing to

       2    remember is this is ‑‑ in agreeing with

       3    Essie, it's just like where we were at in

       4    heart transplantation in 1980, right at the

       5    time of the introduction of cyclosporin,

       6    one‑year graft survivals were in the 20 to 35

       7    percent range.  Most of the centers had

       8    decided they wouldn't do them, and all of a

       9    sudden you introduce this drug and it went to

      10    70, 80 percent within about three years.

      11              You couldn't do a randomized

      12    prospective trial of that and certainly no

      13    one in his right mind would suggest that the

      14    FDA impeded it or in the future should not

      15    learn from how they handled it and impede

      16    something like this.  So I think that's the

      17    point, you know, picking a parameter.  That

      18    was what I was trying to say earlier.  The
      19    parameter there was, let the patients

      20    survive.

      21              DR. MILLER:  You're just proving my

      22    point.  You got the data on the heart

                                                            286

       1    transplant by looking at cyclosporin in

       2    kidney transplants, an easier thing where you

       3    got to do randomized trials and then the

       4    scientists or clinicians in heart transplants

       5    took it the next step and said, okay, this is

       6    a really awful disease, let's go ahead and

       7    use cyclosporin here.  But the data to say

       8    that it's safe and effective was done for the

       9    easier transplants.  So ‑‑

      10              DR. SALOMON:  I think you have to

      11    recognize there's a transition here and

      12    there's a time when you demand these really

      13    rigid wonderful randomize prospective trials

      14    and no one is going to sit here at the table

      15    and not tell you how great they are.  But

      16    there's also a time when you've got to relax

      17    and you've got to just allow an outcome

      18    parameter like the patient survived, or the
      19    patient didn't get GVH, or the patient didn't

      20    relapse.  The patient engrafted better.

      21              DR. SIEGEL:  I understand that.

      22    Obviously different standards apply for

                                                            287

       1    different types.  What I don't understand is

       2    this notion of one parameter.  We've seen ‑‑

       3              DR. VOSE:  There is no one

       4    parameter.

       5              DR. SIEGEL:  We've seen really

       6    extensive excellent T cells depleting in the

       7    IND phase programs where you see no

       8    Graft‑verus‑Host Disease but a tremendous

       9    problem with engraftment rate.

      10              DR. O'REILLY:  But that's gone.  I

      11    mean, that's really old.  I think that's

      12    really become old.  I mean, when Jean's

      13    talking about these haplotype disparate

      14    grafts, or when I'm talking about the

      15    haplotype disparate grafts.  If you gave an

      16    unmodified marrow transplant from a two

      17    antigen disparate individual, your risk if

      18    graft rejection right now is in excess of 15
      19    ‑‑ 12 to 15 percent.  That's the Seattle

      20    series, and there have been several series to

      21    show it.

      22              So if we're talking about something

                                                            288

       1    in the 10 percent or 10 to 15 percent, we are

       2    not talking about an increased incidence of

       3    rejection.  What I would say is, we're now

       4    with that TBI thyoteposide with ATG or ara‑C

       5    or ATG, the fact of the matter is we are now

       6    at a point where the issue of graft failure

       7    following T‑ depleted transplants should be

       8    moot because it's really largely over.

       9              The GVH issue remains because not

      10    all T‑cell depletions are equivalent either

      11    in removing Graft‑ verus‑Host Disease or how

      12    they deal with, for example, whatever

      13    contributes to leukemia resistance.  And I

      14    still think that there are big issues in the

      15    haplotype disparate grafts that we ‑‑ you

      16    know, there are other fine tunings that are

      17    going to make for long‑term survival, not the

      18    least of which is, you know, how do you
      19    choose or what kind of disparity do you have

      20    to get around some of these infectious

      21    problems.

      22              DR. SIEGEL:  But what you are

                                                            289

       1    suggesting, if I understand it, is that the

       2    issue of graft failure.  We can establish the

       3    safety vis‑a‑vis graft failure ‑‑

       4              DR. O'REILLY:  We can establish ‑‑

       5              DR. SIEGEL:  ‑‑ on the basis of a

       6    historical expectation we know what range of

       7    graft success we can now expect.  And if a

       8    new product falls in that range, we can be

       9    relatively comfortable.

      10              DR. O'REILLY:  Yeah.  We're getting

      11    not completely ‑‑ and I recognize you're

      12    hearing this from a guy who has really been a

      13    stomper, you know, in terms of aggressively

      14    trying to avoid some of the issues of the

      15    definition of the stem cells because I

      16    fundamentally agree with certain people such

      17    as Fred Rosen, Harvard, who says, "I've never

      18    seen one."
      19              I don't know what a stem cell is.

      20    But what ‑‑

      21              DR. SIEGEL:  There must be some in

      22    that bag there.

                                                            290

       1              DR. VOSE:  They're in there

       2    somewhere.

       3              DR. O'REILLY:  But I do think that

       4    you take the cord blood, the T‑depleted

       5    transplants, all these ones, you're getting

       6    some fairly reasonable sort of universes in

       7    terms of inadequate dose on the one hand and

       8    then for after the adequate dose you're

       9    talking about what is the kind of

      10    cytoreduction that's required to get one of

      11    these grafts in.  You can take those kinds of

      12    things and put those together.  And from

      13    there you can move and test the device or a

      14    technique.  I really think we're getting

      15    there.  And we're close.  There may be some

      16    mild modifications, but I think we're pretty

      17    close there.

      18              DR. VOSE:  How about this as a
      19    possible suggestion.  If we want to test it

      20    in a randomized fashion to consider testing

      21    it in the matched unrelated setting and then

      22    to do it with a package deal of phase II

                                                            291

       1    trials in the haplo setting so that you show

       2    efficacy in both types of settings, but you

       3    only have the randomized trial in one type of

       4    setting.  What do people think of that?

       5              DR. HENSLEE‑DOWNEY:  Can you say

       6    that again?

       7              DR. VOSE:  Well, if you're going to

       8    test a device or an antibody or whatever

       9    you're going to test to test that in a

      10    randomized fashion in a matched unrelated

      11    setting.  But in order to broaden the

      12    possible applications to test it in a phase

      13    II setting in the haplo setting to compare it

      14    to the historical controls that you're

      15    talking about.

      16              DR. HENSLEE‑DOWNEY:  Right.

      17              DR. VOSE:  So that they would bring

      18    it as a package to the FDA as sort of a type
      19    of a thing.

      20              DR. SALOMON:  The only minor

      21    problem with that though is, if you have a ‑‑

      22              DR. HENSLEE‑DOWNEY:  With targeted

                                                            292

       1    endpoints.

       2              DR. SALOMON:  ‑‑ if you have a 15

       3    percent incidence of GVH in the matched,

       4    right, sibling matched transplants.

       5              DR. VOSE:  No, I'm talking about

       6    matched unrelated donors.

       7              DR. SALOMON:  Or take matched

       8    unrelated, it's still 15 percent.

       9              DR. VOSE:  Much higher.

      10              DR. HENSLEE‑DOWNEY:  No, no, no,

      11    much higher.

      12              DR. O'REILLY:  75 percent.

      13              DR. VOSE:  Much higher, 75 percent.

      14              DR. SALOMON:  That will be fine.

      15    If you start with 15 percent you reduce it to

      16    10 percent ‑‑

      17              DR. VOSE:  No, no, no, no, no.

      18    We're talking 75 percent.
      19              DR. KURTZBERG:  But I mean, the

      20    T‑depletion trial ought to be an example of

      21    how hard it is to do a randomized trial.  I

      22    mean, they keep adding centers just to be

                                                            293

       1    able to get to some marginal ‑‑

       2              DR. HENSLEE‑DOWNEY:  But on the

       3    other hand, you should still be able to

       4    achieve with whatever technology you use,

       5    outcomes similar to published outcomes.  I

       6    mean, that's a part of creating those

       7    endpoints.

       8              DR. MILLER:  But also the T‑cell

       9    depleted trial is power to look at overall ‑‑

      10              DR. VOSE:  Overall survival.

      11              DR. MILLER:  ‑‑ and what we are

      12    saying is whatever trial they do, power to

      13    look at more short‑ term outcomes than to

      14    look at the safety efficacy of the device.

      15    I'm a little concerned about doing ‑‑

      16    transfers because, you know, then you're

      17    changing two things.  Because in that

      18    setting, if you don't T cell deplete, you're
      19    going to have to give additional immuno

      20    suppressants.  So it's not going to be ‑‑ the

      21    best trial would be cyclosporin or FK506

      22    alone versus cyclosporin FK506 with T‑cell

                                                            294

       1    depletion.

       2              Well, if you don't T cell deplete,

       3    you've got to do something else in the

       4    unrelated transplant.

       5              DR. HENSLEE‑DOWNEY:  Actually the

       6    unrelated trial ‑‑

       7              DR. VOSE:  Not everybody does that.

       8              DR. HENSLEE‑DOWNEY:  ‑‑

       9    immunosuppression with the T cells ‑‑

      10              DR. MILLER:  Again, with that

      11    unrelated trial you're not testing the

      12    device, you're testing methodology.  You're

      13    testing, quote, "T‑cell depletion versus

      14    non‑T‑cell" look at the whole outcome.  What

      15    a sponsor needs to do is test the device, so

      16    you really should change just one parameter

      17    and that's going to be difficult to do in the

      18    unrelated setting.  Like this, you know,
      19    getting back to the cell pro trial which was

      20    easy to do for myeloma, they changed one

      21    thing.  It was peripheral blood progenitor

      22    cells, you looked at the ‑‑ you know, one bag

                                                            295

       1    versus the other bag at the end whether or

       2    not how many ‑‑ you know, how many myeloma

       3    cells were there.  You didn't have to change

       4    anything else whereas with the unrelateds

       5    you'd have to change two things.  You would

       6    have to add the immunosuppression to one, and

       7    T‑cell deplete the other which makes it ‑‑

       8              DR. KURTZBERG:  No, I mean, you

       9    would just ‑‑ I don't think so.  I think you

      10    ‑‑

      11              DR. VOSE:  No, I think you could

      12    just do it with having the same depletion,

      13    just adding the depletion.  I think you could

      14    design something to do that.

      15              DR. O'REILLY:  But you would have

      16    differences in cytoreduction regimens.

      17              DR. MILLER:  Right.  You would have

      18    to have some of the other differences.
      19              DR. KURTZBERG:  That's why I'm

      20    saying, test it in the context of an

      21    already‑established ‑‑ whether it's Jean or

      22    Rich, or Milwaukee or ‑‑ I mean, there are

                                                            296

       1    places in this country that do this, and

       2    there aren't that many.  And that's where you

       3    ought to test.

       4              DR. VOSE:  I'm not saying not to do

       5    that.

       6              DR. KURTZBERG:  What?

       7              DR. VOSE:  I'm not saying not to do

       8    that.

       9              DR. KURTZBERG:  I mean, because

      10    otherwise you're going to get people who

      11    don't do it ‑‑

      12              DR. VOSE:  No, you should not ‑‑

      13              DR. KURTZBERG:  ‑‑ starting out

      14    with new technical ‑‑

      15              DR. VOSE:  ‑‑ you shouldn't do it

      16    in places that don't do it, no.

      17              DR. SIEGEL:  If I could clarify,

      18    you made a comment about short‑term versus
      19    long‑term outcomes.  Which are you referring

      20    to as the ‑‑ I know the long‑ term are the

      21    longer ones, but ‑‑

      22              DR. MILLER:  I mean, I think T‑cell

                                                            297

       1    depletion will affect the short ‑‑ the

       2    incidence of acute Graft‑ verus‑Host Disease

       3    in the 100 day mortality and look at

       4    engraftment.  And I think, again, that's what

       5    we're looking at.  We're trying to show that

       6    it reduces acute Graft‑verus‑Host Disease and

       7    allows engraftment.

       8              DR. SIEGEL:  But I guess I would

       9    wonder, and this is what I was wondering is

      10    short or long term, in the past the advice we

      11    have received is even in therapy is that

      12    which did not raise as much concern about

      13    immunologic defects such as CSFs, we've been

      14    advised that the trial should carry out data

      15    at least to the 9 to 12 month range to look

      16    at infection rates and immunological

      17    reconstitution.  I wasn't sure if you were

      18    thinking of that in the short term or the
      19    long term or ‑‑

      20              DR. MILLER:  Well, I think that the

      21    primary endpoint should be you should

      22    probably follow the patients out one year.  I

                                                            298

       1    don't think that in this, you know, that

       2    relapse is, per se, for these trials the

       3    number one endpoint or disease free survival.

       4    Because now there's post‑transplant ‑‑

       5    post‑relapse or immunotherapy or different

       6    things you can do.  And so what you are

       7    actually looking for this device is to see

       8    whether or not you could decrease acute

       9    Graft‑verus‑ Host Disease that will allow

      10    engraftment.  So I think those are what you

      11    should test and then do secondary endpoints

      12    for infections or secondary EBB but a short

      13    term, and not test the long‑term outcome.

      14    Because those are the types of questions

      15    you're going to ask out of ‑‑ you know, more

      16    center‑directed protocols that are designed

      17    to look at that.  Not at the device

      18    specifically.
      19              DR. VOSE:  I think it is important

      20    to follow the patients for maybe a year for

      21    EBB, you know, for lymphoproliferative

      22    disorders and infections, but I think what

                                                            299

       1    we're saying is you don't have to say five‑

       2    year disease‑free survival.  Yeah, something

       3    like that.

       4              DR. O'REILLY:  I also think in this

       5    regard I think as far as I understood it, the

       6    role of the FDA is to protect the public.

       7    That's what they're supposed to be doing.

       8              And, in real terms, for example, in

       9    cytokines, you know, if you're looking at

      10    this as the retrospective scope, you could

      11    look at it in two ways.  One would be, you

      12    know, do the cytokines do what they're

      13    supposed to do in terms of simulating a cell?

      14    You take GCSF or GMCSF, do they simulate the

      15    cell?  The fact is they do.  Can they, as a

      16    result of that, potentially reduce

      17    infections?  The answer there was yes.

      18              Now, based on that, fortunately
      19    those guys got licensed.  But if it were the

      20    issue, does it alter the disease, the fact of

      21    the matter is, these cytokines are supportive

      22    care.  They don't necessarily alter the

                                                            300

       1    outcome of the disease.  Would it be

       2    appropriate for ‑‑ there were several in the

       3    FDA who actually raised this that that's what

       4    they should do.  In other words, you should

       5    give GCSF and the only basis for its being

       6    approved would be that it improved long‑term

       7    survival.  And I think somebody argued

       8    successfully, hey, that's not ‑‑ test it.

       9              My own read of it is, if it's not

      10    really useful in the long run, the

      11    marketplace will tell it pretty quickly, and

      12    it just will be abandoned.  However, in the

      13    process you now have agents that in several

      14    circumstances are of extreme use.

      15              DR. SIEGEL:  No, I think that's a

      16    ‑‑ actually the one part I don't know is

      17    correct is what positions may have been taken

      18    many years ago in the agency, but with the
      19    support of this committee, our position with

      20    the CSFs and consistently has been that those

      21    therapies which are adjunctive to

      22    hematopoietic transplantation need ‑‑ which

                                                            301

       1    includes some of the ones we're talking about

       2    here, including a few cell depletion ‑‑ need

       3    to assess their impact on hematopoietic

       4    transplantation.  And the issue of their

       5    impact on the underlying disease, actually

       6    the advice of this committee in the past has

       7    been ‑‑ and the one that we continue to

       8    promulgate is that if in studying the impact

       9    on transplantation one powers a study out of

      10    it to do that, say 100 to 150 patients, one

      11    must capture ‑‑ one should capture the

      12    outcome of disease of recurrence relapse

      13    rates on those patients as well.  But one

      14    need not power the study to exclude a given

      15    size of adverse effect except potentially in

      16    exceptional cases where specific concerns

      17    might rise like this committee originally

      18    mentioned concerns about the abilities of
      19    GCSF to stimulate myeloid leukemias and that

      20    approval didn't occur until there was

      21    specific evidence excluding the possibility

      22    of a large effect in that regard ‑‑ or a

                                                            302

       1    substantial effect.

       2              But I think that does capture where

       3    we're going and I think that is, unless we

       4    hear otherwise, and I haven't heard otherwise

       5    what we're looking for here.  The realm of

       6    things including immunological reconstitution

       7    engraftment, you know, infections, and

       8    Graft‑verus‑Host Disease, but not tumor

       9    outcomes.  There have, in the past, however,

      10    been concerns expressed from this committee

      11    about the impact on Graft‑verus‑Host Disease

      12    leukemia effect in particular, I guess, in

      13    the allogeneic setting.

      14              And is what we're hearing that ‑‑

      15    what are we hearing ‑‑ let me not guess, but

      16    let me ask about that.  What would it take

      17    theoretically to make sure that you weren't

      18    adversely impacting that and what is it
      19    reasonable that ‑‑ because, you know ‑‑

      20              DR. HENSLEE‑DOWNEY:  The most

      21    important thing ‑‑

      22              DR. SIEGEL:  ‑‑ what sort of data

                                                            303

       1    are you going to want see when you see these

       2    products to make sure that you're not ‑‑

       3              DR. HENSLEE‑DOWNEY:  The most

       4    important thing would be a consistent patient

       5    population.  Because the disease and the

       6    status of the disease is going to be more

       7    powerful, particularly probably in the use of

       8    alternative donors than perhaps T‑cell

       9    depletion will be.

      10              So you'll have to study the exact

      11    same patients if you wanted to ask it in a

      12    randomized trial.

      13              DR. KURTZBERG:  And when you're

      14    first testing your device, you're not going

      15    to look at your easiest patients to study

      16    that, you're going to look at your poorest

      17    patients.  And essentially get a negative

      18    answer with that group.
      19              DR. HENSLEE‑DOWNEY:  So I think

      20    that's probably an unrealistic goal to expect

      21    to answer those questions in these trials

      22    that would be really looking at developing

                                                            304

       1    technology that could facilitate

       2    transplantation.

       3              DR. SIEGEL:  It would follow then

       4    that if the trial were done in a less

       5    homogeneous population where you couldn't

       6    assess that, although those questions would

       7    be outstanding, you're saying that if that

       8    trial demonstrated a reasonable impact on

       9    engraftment parameters that that ought to

      10    suffice if nothing jumped out in terms of an

      11    adverse problem.

      12              DR. VOSE:  But that's sort of if

      13    you did have a lot of different patient

      14    populations in a trial like that, they need

      15    to be balanced for those, I think is what

      16    Jean is saying, so that you're not, you know,

      17    putting all the bad patients in the T‑cell

      18    depleted arm, for example, that wouldn't be
      19    appropriate.

      20              And the other issue ‑‑

      21              DR. HENSLEE‑DOWNEY:  Well, you even

      22    have patients you can just ask the question.

                                                            305

       1              DR. VOSE:  Right.

       2              DR. HENSLEE‑DOWNEY:  And one of the

       3    ways you can do that is you can look at even

       4    the data in matched sibling donors.  If

       5    you're relapse rate is not outside of the

       6    sort of range that you would expect relapse

       7    to occur in the matched sibling donor

       8    setting, then you don't need to really raise

       9    your eyebrows because that's a feature of the

      10    underlying disease.

      11              DR. VOSE:  One other issue I just

      12    wanted to bring up too that we didn't really

      13    discuss was that I think any trial like this

      14    needs to have a quality of life component as

      15    one of the important endpoints, too.

      16              You're smiling, Jay.

      17              DR. SIEGEL:  Oh, we've been in the

      18    midst of ‑‑ in totally unrelated situations
      19    and diseases there's a great deal of

      20    controversy at the present time as exactly

      21    what quality of life means and how you

      22    establish a ‑‑

                                                            306

       1              DR. VOSE:  Speaking from my own

       2    from my own viewpoint and from these guys,

       3    I'm sure they'll tell you that the quality of

       4    life of some of these patients that have bad

       5    Graft‑ verus‑Host Disease is awful.  And so I

       6    think, you know, that is an important

       7    endpoint in this kind of patient population.

       8              DR. KURTZBERG:  But you're looking

       9    at a much later endpoint.  I mean, I think ‑‑

      10              DR. VOSE:  That's chronic.

      11              DR. KURTZBERG:  ‑‑ if you want to

      12    get devices into the marketplace so they can

      13    really be worked out and tested, then you

      14    want to look at short‑term endpoints, acute

      15    GVH engraftment and 100‑day infection rate.

      16              DR. VOSE:  Right.  But even acute

      17    GVH, I mean, there's quality of life issues

      18    with that as well.
      19              DR. KURTZBERG:  Yeah, but I don't

      20    know that you have to do special measurements

      21    because you can measure bilirubin and stool

      22    volume and rash for a lot less money and get

                                                            307

       1    the same information.

       2              DR. VOSE:  I think it's important

       3    personally.

       4              DR. KURTZBERG:  I think later when

       5    you do, you know, the phase II kind of trials

       6    and phase III trials you measure that.  But

       7    that's not where this would be.

       8              DR. VOSE:  Well, we're talking

       9    about a phase III trial.  We're talking about

      10    a randomized trial.  So that would be.

      11              DR. O'REILLY:  Well, you know, I

      12    think one of the issues that's going to come

      13    up would be if you ‑‑ if you assume that

      14    there was equivalency, and I don't think that

      15    that's going to be the case ‑‑

      16              DR. VOSE:  Equivalency of?

      17              DR. O'REILLY:  Let's say T‑depleted

      18    versus unmodified would be ‑‑ in the haplos
      19    they're not going to be equivalent, I mean,

      20    that's not an issue.  But, I mean, even in

      21    the matched sibling, if they were equivalent,

      22    then the quality of life circumstance you

                                                            308

       1    would really need to develop the kinds of

       2    useful parameters of quality of life that

       3    everybody can agree to.  That has been the

       4    real bugaboo and I think that that's what

       5    you're saying.  They're very loose,

       6    unfortunately, that's the problem.  They've

       7    been cited in several papers, but they become

       8    very loose.

       9              My own read of it is though that in

      10    terms of issues like acute GVH and other

      11    things, if T‑depleted grafts are going to be

      12    good in the long term, and I think they are,

      13    and certainly in certain diseases they are

      14    sort of almost like a treatment of choice,

      15    then, you know, I think that in very real

      16    terms they should be able to do it and not

      17    just on that.

      18              DR. SIEGEL:  I guess in part this
      19    question is ‑‑ we've been having a very

      20    useful discussion that moved all around the

      21    actual formal questions we wrote which is

      22    fine.  In part we're getting to some of the

                                                            309

       1    issues in number three which is less whether

       2    you have an integrated measure of quality of

       3    life, but how you do integrate different

       4    outcomes.  If it's anticipated in a certain

       5    setting that the patients on the treatment

       6    arm may have less Graft‑verus‑Host Disease

       7    and say more infections, or a worsened

       8    outcome in terms of engraftment rates where

       9    we faced this situation before and it's often

      10    very difficult to figure out how to integrate

      11    that.  I'm not sure there's a way to answer

      12    those questions prospectively.  Sometimes you

      13    almost have to, you know, look at it and then

      14    we come back to you and you say, well, why

      15    did they design the trial that way ‑‑ or done

      16    a different trial.

      17              But I wonder what ‑‑ are there

      18    specific comments on how to look at all of
      19    these parameters?  It's easy if one thing is

      20    better like Graft‑verus‑Host and everything

      21    is the same or better or equivalent within

      22    height statistical bounds.  But any

                                                            310

       1    particular thoughts about the tradeoffs that

       2    are appropriate or reasonable in these

       3    settings?

       4              DR. AUCHINCLOSS:  Well, I think in

       5    that context I guess I'd sort of like to go

       6    back to this graft versus leukemia effect

       7    which I got the sense everybody was sort of

       8    pooh‑poohing.  To me it was ‑‑

       9              DR. O'REILLY:  No, no, I mean,

      10    certainly from my standpoint, no.  The allo

      11    effect is very real.  If you look at the

      12    instance of relapse following a congeneic

      13    twin graft in AML and first remission, at 60

      14    percent, that's what it is.

      15              DR. AUCHINCLOSS:  I mean, that to

      16    me would be the critical issue in a T‑cell

      17    depleted graft is what is going to happen ‑‑

      18              DR. O'REILLY:  And all that has
      19    come out of where we're at is ‑‑ and all

      20    we're saying is that it goes beyond the allo

      21    effect of GVH because the incidence of

      22    relapse remains extremely low in the acute

                                                            311

       1    leukemias.  In CML, on the other hand ‑‑

       2              DR. AUCHINCLOSS:  That you can

       3    separate the two?

       4              DR. O'REILLY:  Yes.  I understand

       5    that and I believe that's true.  But it's

       6    something that you need to actually ‑‑ I

       7    think it's the most important variable in

       8    this mix of what you're trying to determine

       9    out of ‑‑

      10              DR. AUCHINCLOSS:  I agree with

      11    that.

      12              DR. KURTZBERG:  I'm concerned that

      13    the infrastructure isn't in place to answer

      14    all these questions.  I don't think they're

      15    bad questions, but this is years ahead of

      16    where the field is.

      17              DR. O'REILLY:  I understand that.

      18              DR. KURTZBERG:  And if this is what
      19    the requirements are going to be and they're

      20    noble, then how are they going to be funded?

      21              DR. HENSLEE‑DOWNEY:  How do you get

      22    the right patients?

                                                            312

       1              DR. O'REILLY:  See, one of the

       2    things I'm also ‑‑ part two of the questions

       3    to be asked was, you know, the issues of

       4    covariates.  I'm also really interested in

       5    what the feeling of the group would be now

       6    vis‑a‑vis the kinds of patients that we do.

       7    Because one of the biggest covariates that we

       8    have is the stage of disease.  And right up

       9    to now the haplotype disparate grafts are in

      10    a position where at least you're saying you

      11    got a lot less GVH than you would expect in

      12    the unmodified grafts.  The incidence of

      13    engraftment is certainly within the realm of

      14    what you would get with in a modified graft,

      15    but the results in different groups basically

      16    reflect the risk categories that we're

      17    talking about.  And the fact of the matter is

      18    if we gave an unmodified graft now to the
      19    high‑risk cases that Jean does or I do,

      20    long‑term disease‑free survival is 10 to 12

      21    percent if it's that.  So is that our

      22    equivalence rate, or do we basically say

                                                            313

       1    perhaps what we really should be doing is

       2    really looking at this in, you know, earlier

       3    disease.  When in real terms we can ‑‑ and

       4    that was one of the questions that was raised

       5    before.  And I think that that's a really

       6    important one.

       7              There are downsides to it, but

       8    there are also some big upsides in terms of

       9    being able to see a meaningful result.  That

      10    it's not quite so tarnished by the vagaries

      11    of the patient's disease or the prior therapy

      12    which so oftentimes mixes things up.

      13              DR. VOSE:  That's why I think you

      14    should do the little bit better population in

      15    the matched unrelated setting and then for

      16    the phase II trial that you guys, you know,

      17    are talking about in doing to do that with

      18    the poor‑risk population and then if they
      19    come with both of those types of populations

      20    into a separate type of trials, then that

      21    looks a little bit at both of those issues.

      22    It's a difficult question, I don't know.

                                                            314

       1              Sure.  Please identify yourself.

       2              AUDIENCE:  Mike ‑‑ Nexell.  One of

       3    the things that we're seeing with the

       4    technology as it improves is the ability to

       5    deplete T cells to the point where folks are

       6    adding back to the graft ‑‑ graft

       7    engineering.  And I didn't want to leave

       8    today without throwing that out for

       9    discussion since what people add back to the

      10    graft is going to be independent of my

      11    ability to deplete T cells.  And I think it

      12    gets back to the system depletes T cells then

      13    people are going to engineer graft for the

      14    graft failure issues or the GVL.  And I think

      15    that's got to ‑‑ we're going to be faced with

      16    that in trying to run a trial in unrelated

      17    donor setting where they're going to be

      18    concerned about that.
      19              DR. SIEGEL:  Actually that opens up

      20    sort of an aspect of ‑‑ I think it was in one

      21    of our questions, the first question

      22    regarding differing in the amount of T cell

                                                            315

       1    depletion.  One design that's been discussed,

       2    I wonder how the committee would react to

       3    this, would be using the same device, either

       4    using it more or less intensively or with

       5    various add back to do a controlled trial

       6    where you gave a graft with different amounts

       7    of T‑cell depletion both being within the

       8    realm of what's considered acceptable,

       9    potentially acceptable for whatever disease

      10    and a degree of matching your treating, but

      11    then through that comparison being able to

      12    show that substantial difference in the

      13    amount of T‑ cell depletion had significant

      14    impacts on Graft‑verus‑ Host Disease and/or

      15    other parameters in such a way that one might

      16    be able to conclude in combination with

      17    comparison to historical expectations that

      18    one or both regimens was a particularly
      19    useful regimen.

      20              DR. AUCHINCLOSS:  I read that

      21    portion and I found it very interesting

      22    because it seemed to me the logic of it was

                                                            316

       1    to start with the assumption that the device

       2    works and then see if you can find some

       3    number at which the device doesn't work.  And

       4    I wasn't sure that that's an appropriate way

       5    to run a trial.

       6              DR. HENSLEE‑DOWNEY:  I have a

       7    concern too.  And that is reading what you've

       8    provided to us is that there's sort of an

       9    assumption that already we know that we

      10    should go to the peripheral blood compartment

      11    to obtain haploidentical cells.  And I don't

      12    think in any way we're there.  And perhaps

      13    before you can ask any of those questions,

      14    that might be a very good question to ask.

      15    To what extent is the marrow and the

      16    peripheral blood different and how does it

      17    demonstrate that in a haploidentical

      18    recipient?  We don't have those answers at
      19    all.

      20              DR. MILLER:  But that's the

      21    responsibility of the transplant community

      22    not the FDA or the sponsors to show whether

                                                            317

       1    peripheral blood or bone marrow is better.

       2              And I agree, I have a hard time

       3    with the ‑‑ you know, with the assumption of

       4    trying to find a different level of T cells.

       5    Because the only way that it will work is

       6    that if the one ‑‑ to show that you can get

       7    the drug approved if the one is better than

       8    the other.  And you're never going to get

       9    anybody ‑‑ I mean, if the one is clearly

      10    better than the other, can you then

      11    extrapolate to zero?  I think that's really

      12    pretty dicey.

      13              DR. WEISS:  There are a lot of

      14    study designs though were you an just do dose

      15    response.  And we had it all the time in

      16    conventional drugs where you have maybe

      17    slightly better efficacy results at the

      18    expense of a little more toxicity and dose
      19    rate designs ‑‑ I mean, Dr. O'Fallen has been

      20    very quiet.  And, you know, there are ‑‑ the

      21    comparisons are maybe not as great sometimes

      22    between those and actually more conventionals

                                                            318

       1    do have a, you know, control arm, a high dose

       2    and a low dose for instance is much more

       3    conventional ‑‑ to see.  But you can do

       4    things with several ‑‑ you know, at least one

       5    or more different doses and doing some

       6    comparisons on looking at dose responses.

       7    And it isn't always one works and one

       8    doesn't, and it always, you know, deluding

       9    ourselves that we're giving something when

      10    really we're actually giving somebody

      11    basically nothing.  It's really the idea that

      12    you're having a range of responses.

      13              DR. MILLER:  I think the more

      14    interesting thing would potentially be

      15    something like they're doing potentially had

      16    donor in their sequential studies at Sloan

      17    Kettering, just do the first step and then

      18    compare the first step with one plus two.
      19    And then if you feel you had reasonable data

      20    with the one step, adding the second step to

      21    see if it's better than add T‑cell depletion

      22    with equivalent engraftment.  And that may be

                                                            319

       1    like ‑‑

       2              DR. O'REILLY:  Yeah, that may ‑‑

       3              DR. MILLER:  Could you do that, do

       4    you think?

       5              DR. O'REILLY:  ‑‑ that's

       6    potentially possible.  I mean, one of the

       7    issues that has come up with us with regard

       8    to the doses is that in terms of the assay

       9    systems we have now for looking at, for

      10    example, doses of T cells in the matches we

      11    got a fairly clean circumstance, but what I'm

      12    disturbed by is that in the haplotype

      13    disparate or unrelated it's not.  They're

      14    all, you know, those who do and don't get GVH

      15    are in the same universe.  And until we

      16    really have a much cleaner view of what is

      17    the actual alloreactive cell, we're a little

      18    caught, you know, several groups have also
      19    looked at, for example, HTLPs and CTLs

      20    precursors, and assays in an attempt to

      21    quantitate these and to then correlate that

      22    with Graft‑verus‑Host Disease.  And thus far

                                                            320

       1    they've gotten again kind of mixed grill

       2    results unfortunately.

       3              In the unrelated circumstance

       4    Carolyn Keeber has been with us and is the

       5    co‑author of the LDA studies looking at the

       6    mixed T cells when she tried to look at this

       7    for host‑specific CTLs or host‑specific HTLPs

       8    thus far the clear correlations have not been

       9    there.  So I think a dose response approach

      10    can be used.  We're using it late after the

      11    transplant and I think that that really has

      12    offered us some real options because late

      13    after transplant the potential to induce GVH

      14    is considerably different from the time up

      15    transplant.  And that has opened up some real

      16    possibilities.  Whether that's going to be

      17    possible in the mismatched graft, my own bet

      18    is it will not because it just takes a few
      19    alloreactive T cells to do the job.

      20              I would like though, you know, this

      21    issue that was raised before with regard to

      22    the issue of a T‑ depleted transplant, and

                                                            321

       1    what do you do to it is going to be sort of

       2    thought about.  And I think it is a real

       3    problem because in the one ‑‑ what we're

       4    caught by is you've got a huge number of

       5    industrial groups now that have different

       6    techniques that potentially can produce good

       7    T‑cell depletion that want to get into

       8    clinical trials and people want to actually

       9    get to do the trials.  But the next step is

      10    not just the T‑cell depletion, the step is

      11    going to be T‑cell depletion for example plus

      12    genetically modified effector cells that are

      13    in fact overt alloreactive T cells that could

      14    be used to actually induce a control GVH

      15    response where you can eliminate those cells

      16    but those cells could allow you to get grafts

      17    in.

      18              And that's going to ‑‑ I think that
      19    the options now are extraordinary and the

      20    query that we have to get to is exactly what

      21    Hugh said and Carole is saying is we have to

      22    get some sort of a system that allows us at

                                                            322

       1    least to have a biological readout which will

       2    at least give some kind of a ‑‑ you know,

       3    even something like a tentative approval.  I

       4    don't know, at least to the point where, you

       5    know, someone can sell them and someone can

       6    actually pay for them.  I mean, like a center

       7    doing trial could actually because I can't do

       8    this on philanthropy.

       9              DR. VOSE:  It is a problem because

      10    we're always trying to be one step ahead and

      11    the approval is always kind of ten steps

      12    behind.  So, I mean, it's a problem.  I

      13    agree.

      14              MR. VANEPPS:  Dennis VanEpps from

      15    Nexell as well.  I just wanted to reiterate

      16    some things that Mike had mentioned here from

      17    the company side.  I think we're in the

      18    position now where we ‑‑ in much of the
      19    recent data that we have that we have a

      20    device that will virtually eliminate the

      21    majority if not all ‑‑ close to all the T

      22    cells.  The problem is that what I heard here

                                                            323

       1    is that we're trying to get to the point

       2    where we can manipulate the T cells

       3    population.

       4              Now, it's much more difficult to

       5    try to make a device manipulate the exact

       6    number of T cells that you want to have

       7    harvested in the final product.  And

       8    ultimately what happens is, just as you had

       9    mentioned here, Rick, that you're going to be

      10    adding bad T cells at some point.  And you

      11    can control the number of T cells that go

      12    back in.  That really becomes a T cells

      13    therapy, I think, outside of the device.

      14              And I get back to the issue of the

      15    device is designed to remove the T cells that

      16    allows you now to do the T cells therapy.

      17    And so, if that's the purpose of the device

      18    and the cells will you allow then to do an
      19    efficient transplant and get reasonable

      20    engraftment comparable to what's done now,

      21    then I think the rest of everything that goes

      22    beyond that, then the T cell therapy is

                                                            324

       1    really a totally separate issue and really is

       2    the future of all the studies that will go on

       3    beyond having the device approved.  Obviously

       4    a biased opinion on my part, but that's ‑‑

       5              DR. MILLER:  How are the cell

       6    therapeutic machines regulated?  I mean, why

       7    is T‑cell depletion devices, if they're

       8    actually used, just to separate out these

       9    cells different from like the code spectra or

      10    something like that and who ‑‑ which we also

      11    take the cells out and sort of manipulate

      12    them back.  Is this considered different

      13    because we're ‑‑ it's sort of part of a

      14    process as compared to just getting us a

      15    population of cells?

      16              DR. SIEGEL:  I can't tell you

      17    specifically about the device to which you're

      18    referring other than I would be very
      19    surprised if it's not an FDA‑regulated

      20    device.  It could be regulated ‑‑ yeah, some

      21    devices are regulated in the Office of Blood

      22    some in the office you're with which is the

                                                            325

       1    Office of Therapeutics because of their ‑‑ of

       2    where they're used and how they're used and

       3    some in the center for devices.  They're all

       4    regulated, however, under the same laws

       5    pertinent to the regulation of devices.

       6              DR. MILLER:  So I think we're a

       7    committee that's used to looking at ‑‑ or

       8    physicians or groups that are very much more

       9    used to looking at drugs which is much easier

      10    and that's why I was sort of wondering

      11    whether that committee ‑‑ how they deal with

      12    that like the sponsor is saying, you know,

      13    this device we give you a product, what you

      14    do with the product is then your decision.

      15    Tell me how good ‑‑

      16              DR. SIEGEL:  Yeah.

      17              DR. MILLER:  And that's, I guess,

      18    what the hematologic products do, they say,
      19    okay, how well can you collect out the

      20    platelets.  What you do with the platelets

      21    after that is up to you.

      22              DR. SIEGEL:  That's actually not

                                                            326

       1    correct.  Platelets are also an FDA‑approved

       2    product.  They have to meet performance

       3    standards and ‑‑

       4              DR. MILLER:  But for qualitative.

       5    You don't go in and see ‑‑ you don't have to

       6    give them back a ‑‑ so the patient doesn't

       7    bleed.  You don't have to show that you have

       8    a product that has the ‑‑

       9              DR. SIEGEL:  If you were to make a

      10    new preservative solution for platelets a new

      11    way to store platelets, a new way to freeze

      12    them or whatever, the requirements on those

      13    platelets would involve parameters to

      14    establish that you still had an effective and

      15    safe product whether that efficacy would be

      16    determined by in vitro or by in vivo studies,

      17    by bleeding rates or petechia or aggregation

      18    rates, I can't tell you and it probably
      19    varies depending on the issue.  But they are

      20    a valuation for efficacy as well as for

      21    safety.

      22              And devices in general are ‑‑

                                                            327

       1    although there is some difference in

       2    classifications of devices there are certain

       3    types of what are considered low‑risk devices

       4    setting intravenous tubing which may not

       5    require the same sorts of clinical trials as

       6    certain types of ‑‑ like I say, cardiac

       7    bypass pump might.

       8              I think your point is well taken

       9    that this committee, as compared to other

      10    committees, just as these regulators at this

      11    table as compared to some other regulators

      12    have less familiarity with the regulation of

      13    devices than with the regulation of drugs and

      14    biologics and that does raise complex area

      15    issues.

      16              I can assure you that we are in

      17    constant and regular contact with our

      18    colleagues who regulate devices on a regular
      19    basis.  I personally meet on a monthly basis

      20    with my counterpart office director in the

      21    Center for Devices so that you hear

      22    interpreted through me, you know, when I'm

                                                            328

       1    talking with you about what are the standards

       2    ‑‑ what a device does or doesn't have to

       3    show.  We hope that we are applying those

       4    standards and those laws in a level and equal

       5    way.  It's a constant issue and requires

       6    attention.  And I think we recognize that

       7    it's difficult for this committee to, you

       8    know, even for issues that don't come up as

       9    often, say, as accelerated approval if we

      10    deal with the drugs committee to understand

      11    the legal ramifications for that and how to

      12    apply it can be difficult.  It gets more

      13    difficult with devices, on the other hand,

      14    most of the device panels don't have anything

      15    like the expertise in transplantation that

      16    one finds in this committee.  So we get our

      17    advice where we can.

      18              DR. VOSE:  Are there other
      19    questions that we haven't talked about that

      20    you would like to discuss?  I mean, in the

      21    other two questions we kind of discussed in

      22    ‑‑

                                                            329

       1              DR. HENSLEE‑DOWNEY:  One of the

       2    questions that you did write down, number

       3    two, had to do with whether you did try to

       4    conduct a trial or oversee a trial that used

       5    the IBMTR experience as a historical control.

       6    And you asked about what kind of covariate

       7    would be important.  And I did write down a

       8    list of ‑‑ that I would be glad to share with

       9    you if you would like me to.

      10              DR. VOSE:  Well, do you think it's

      11    appropriate to do IBMTR as a control for ‑‑

      12    for what?

      13              DR. HENSLEE‑DOWNEY:  That's another

      14    question.

      15              DR. VOSE:  Well, no, why worry

      16    about the covariate ‑‑

      17              DR. HENSLEE‑DOWNEY:  Ask this

      18    question and I responded to the ‑‑
      19              DR. VOSE:  There's no sense

      20    worrying about the covariates if you don't

      21    think that's adequate control.

      22              DR. HENSLEE‑DOWNEY:  That's true

                                                            330

       1    too.  And I think that the list of covariates

       2    is long enough that it is going to be very

       3    hard to go in and find those matching in the

       4    IBMTR historical bank so that it's probably

       5    unrealistic, I think I could answer it that

       6    way.

       7              DR. SIEGEL:  Are you suggesting

       8    then that it would be preferable to do

       9    randomized‑control trials in all of these

      10    indications and settings?

      11              DR. HENSLEE‑DOWNEY:  No.  Actually

      12    I thought it would be preferable ‑‑

      13              DR. SIEGEL:  Well, don't bother,

      14    because there's no way we'll ever know.  I'm

      15    sorry.  I don't want to put words in your

      16    mouth, but if we're not going to have an

      17    internal randomized control group ‑‑ external

      18    control group.  And you're saying that the
      19    IMBTR is not a suitable one.

      20              DR. HENSLEE‑DOWNEY:  It's going to

      21    be a very difficult one, very difficult one

      22    to get the right ‑‑ to be able to match the

                                                            331

       1    right covariate so that it's a meaningful

       2    historical control group.

       3              DR. SIEGEL:  Yeah.

       4              DR. HENSLEE‑DOWNEY:  I mean, you

       5    could make an effort at it, but it's going to

       6    be hard.

       7              DR. MILLER:  I mean, that's why I

       8    asked the question at the very beginning.  Do

       9    we have a control group that ‑‑ you know,

      10    does anybody have a comparable control group

      11    because if we ‑‑ I think I feel very

      12    comfortable with the fact that we have a

      13    control group that you have confidence in

      14    that you compare then you don't need a

      15    randomized trial.  But you have to have

      16    something.  And I asked a question that came

      17    around from the very beginning is that there

      18    wasn't that ‑‑
      19              DR. SIEGEL:  Well, it sound to me,

      20    from what I've heard from many of you,

      21    including the presentations, is that we saw

      22    this in some when we ‑‑ I think coming from

                                                            332

       1    your institute Dr. ‑‑ talked about

       2    mobilization that what has commonly been done

       3    as a control group is the most recent prior

       4    series in the same institution which maybe

       5    has the same conditioning, variable ‑‑

       6              DR. HENSLEE‑DOWNEY:  Right.

       7    Exactly.

       8              DR. SIEGEL:  ‑‑ but you change one

       9    factor at a time.

      10              DR. HENSLEE‑DOWNEY:  And I think

      11    that potentially could be done.

      12              DR. VOSE:  You know, I think that

      13    the problem ‑‑

      14              DR. HENSLEE‑DOWNEY:  Because

      15    there's less changes.  I mean, even though

      16    there might be a new great infectious disease

      17    drug that might come along and save a few

      18    more patients in the new series.  But still
      19    the changes happen very slowly in reality.

      20              DR. VOSE:  The problem with ‑‑

      21              DR. SIEGEL:  ‑‑ are better

      22    controlled than in external ‑‑

                                                            333

       1              DR. VOSE:  Yeah, the problem with

       2    the IBMTR is that most of the data is old

       3    data and it is from multiple different

       4    institutions and the data is not as well

       5    collected as a single or two centers for

       6    example.  So I think that suggestion of doing

       7    the immediately prior, you know, historical

       8    control at an institution ‑‑

       9              DR. O'REILLY:  You know, you could

      10    however do a little bit a preempting here

      11    because I do think at some time down the line

      12    in the not too distant future the trial will

      13    be, for example, the haplotype two or three

      14    antigen disparate graft versus the unrelated

      15    graft.  Okay.

      16              DR. HENSLEE‑DOWNEY:  That's what I

      17    ‑‑

      18              DR. O'REILLY:  And my own read of
      19    it is that the NMDP database is a pretty

      20    tight database at the present time.

      21    Certainly the National Heart Lung and Blood

      22    trial is a very, very ‑‑

                                                            334

       1              DR. VOSE:  That trial is good.  I'm

       2    not sure that the NMDP is quite as good.

       3              DR. O'REILLY:  Okay.  But I agree

       4    with that.  But even in that group that might

       5    at least give you some kind of background

       6    data these are the effects of age, disease,

       7    stage of disease in terms of long‑term

       8    results.

       9              DR. MILLER:  Actually, that is a

      10    potential control group.  You could

      11    potentially use the ‑‑ I didn't think about

      12    that.  You couldn't potentially use the

      13    methyltracsate cyclosporin on that randomized

      14    trial as the largest group of patients with

      15    ‑‑ or unrelated transplants collected in a

      16    similar way to use if you want to compare

      17    unrelateds with a T‑cell depletion one T‑cell

      18    depletion method, I guess.
      19              DR. O'REILLY:  Yeah, it's not going

      20    to give you the absolute clean thing, but it

      21    would certainly give the FDA at least some

      22    sense of security that in fact insofar as

                                                            335

       1    historically, for example, the incidence of

       2    grade II to IV GVH in a matched unrelated

       3    donor recipient pairing is roughly equivalent

       4    to what you have with a two antigen disparate

       5    within the family.  Now, that may shift as we

       6    get into better attuned typing.  But still in

       7    all, if you had something close to

       8    equivalents or somewhere in that, or you were

       9    looking favorable in comparison to that

      10    circumstance, you would probably be able to

      11    feel relatively secure that certainly the

      12    public was being well served.

      13              And that's a reasonable one.

      14              DR. O'FALLEN:  I'm finally going to

      15    weigh in then.  I thought we had someone made

      16    a position statement earlier that the

      17    historical controls were really out of the

      18    question because we were faced with an
      19    environment here in which things are changing

      20    so rapidly and I was awed by the three

      21    presentations to exactly that same position.

      22    So if we're going to start saying positive

                                                            336

       1    things about historical controls, I have to

       2    wake up here and weigh in.

       3              I think they are just fraught with

       4    all sorts of problems.  The idea of doing

       5    these little stage‑wise studies, that's just

       6    wonderful.  And you're doing the best job you

       7    can do of having not quite concurrent

       8    controls by doing that.  But if you're going

       9    to mount a moderately large study with the

      10    kind of framework of a clinical trial, but

      11    trying to use historical controls, I don't

      12    think that that's got a chance.

      13              DR. O'REILLY:  My only point on

      14    that though is, I think it does give you a

      15    framework and it would provide you with a

      16    reasonable approach to the construction of

      17    stopping rules within trials.

      18              DR. O'FALLEN:  Oh, that's a
      19    completely different thing.  I agree with it

      20    completely.  Of course we should use every

      21    piece of information we possibly can and even

      22    to going to the point of having the ‑‑ I

                                                            337

       1    think someone suggested earlier, a panel of

       2    experts get together and decide what targets

       3    we ought to be having for what could be

       4    equivalently a phase II kind of study to see

       5    if we can even approach those targets.  It's

       6    not a complete replacement for a randomized

       7    clinical trial, but at least it's a real

       8    organized systematic way of taking advantage

       9    of all the data that you can to come up with

      10    some targets.  But it isn't letting someone

      11    choose their favorite historical control

      12    group or their favorite registry group to

      13    decide what their own favorite target is.

      14    It's quite a different picture.

      15              DR. VOSE:  Chris, the NMDP database

      16    is the same as the IBMTR database for those

      17    particular patients.  They share information

      18    so ‑‑ it's the same thing.
      19              Other issues or questions that we

      20    didn't talk about, anybody wants to talk

      21    about?

      22              DR. SIEGEL:  There's one ‑‑ I do

                                                            338

       1    think you raised ‑‑ in fact, I understand Pat

       2    has come up in some discussions with sponsors

       3    which would be a developmental program in

       4    which perhaps in some settings in which

       5    T‑cell depletion is considered more optional,

       6    for example, I guess matched or nearly

       7    matched unrelated, there be control trials

       8    with the possibility of extending

       9    observations with ‑‑ through externally

      10    controlled trials in some settings in which

      11    it would be difficult there or impossible to

      12    do a non‑T‑cell depletion.  Is there a

      13    general feeling in which case although if in

      14    fact in the second ‑‑ the latter case it was

      15    impossible to get data other than

      16    historically controlled you would have in

      17    support of that the control in the other

      18    setting which would lend some, I guess,
      19    intellectual credence to any conclusions you

      20    might make about impact of Graft‑verus‑Host

      21    Disease; is that a correct understanding of

      22    what was proposed?  And is that a type of

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       1    package that people might ‑‑ that this

       2    committee ‑‑ after all, what we're talking

       3    about ultimately, you're going to see the

       4    results of these trials and we recognize that

       5    perfect trials undoable and there's always

       6    parts of the data that come in that we're

       7    going to be unhappy with.  Is that a type of

       8    package there's thought would be a ‑‑

       9              DR. VOSE:  I think that's about the

      10    best you're going to be able to do under

      11    these circumstances.

      12              DR. SIEGEL:  I'm not suggesting

      13    that there's only one way to do that or that

      14    we would make that a requirement.

      15              DR. VOSE:  And then you could use,

      16    you know, the most recent cohort from other

      17    institutions to compare to ‑‑ in a loose way

      18    to the phase II haplo portion of that.
      19              No more questions?  Comments?

      20    Okay.  Thanks to everybody for coming.

      21                   (Whereupon, at 3:30 p.m., the

      22                   PROCEEDINGS were adjourned.)

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