swelling
attack just three months after he lost his dad.
He was about eight years old. He
came to me one morning, showed me his swollen hand and said, "Mommy, I
think I have some of dad in me."
Norm would be extremely proud that
we are here today continuing to work to approve a C1 inhibitor replacement
therapy for my son. We can't bring my
husband back, but you have the power to save countless other lives. Thank you.
MR. JEHN: Diane Dorman.
MS. DORMAN: Thank you for the opportunity to speak to you
today about the importance of an FDA approved treatment for HAE. I am Diane Dorman, Vice President for Public
Policy for the National Organization for Rare Disorders. I have no known financial relationship with
LEV or its competitors nor does the consumer organization that advocated for
enactment of the Orphan Drug Act in 1983.
We continue to monitor implementation of the law especially encouraging
research and development of new treatments for rare orphan diseases.
Our most important mission is to ensure
that research on rare diseases is widespread and productive leading to
medicines, biologics, humanitarian devices and diagnostics that will help
patients with rare diseases. We support
the incentives in law that simulates companies to do orphan drug research. We want safe and effective products to get to
market as quickly as possible.
Treatment for HAE has been available
in Europe for more than 35 years, but there is no approved treatment yet in the
For those who are undiagnosed or
have an attack so debilitating that they cannot advocate for themselves, there
is likely to be an emergency room that will give them medications or even
surgery that will not even help them.
Experience tells NORD that the approval of an orphan product in the
We ask you to keep in mind that HAE
is a life-threatening disease and after 35 years patients cannot risk waiting
any longer. Several times in past years
hopes were destroyed when investigational biologics for HAE did not prove to be
effective and development was stopped.
We ask you now to review the data for Cinryze keeping in mind that there
are no other treatment options available in the American market. HAE patients are desperate for a safe and
effective treatment and like to remind you that many of patients with rare
diseases are willing to take on a far greater risk than those people who are
affected by diseases that affect much wider populations.
Thank you.
MR. JEHN: That is all of the speakers we have registered. Is there anybody else that wanted to make any
comments before we close the open public hearing?
(No verbal response.)
CHAIRMAN SIEGAL: Okay.
Thank you very much for all that helpful discussion.
OPEN COMMITTEE DISCUSSION
CHAIRMAN SIEGAL: And we will proceed to further open Committee
discussion if there is any. Are there
any further questions by the Committee?
DR. BALLOW: Yes, I have a question that's going to be
related to one of the questions that the FDA is going to ask us to vote upon and
that is about post marketing surveillance with regard to inhibitors or
antibodies and I'm a little confused.
But it looks like there's a lot of issues with regard to the assay for
inhibitors or antibodies against this particular protein.
And there's no sense asking the
company to do this kind of surveillance if the assays are not good. So could someone clarify whether the assay is
a good assay (1) and (2) do we actually have a lab that's reliable to do these
assays?
DR. ZURAW: This is Bruce Zuraw again. I'll try to answer that question. I think the assay is not a difficult assay,
but it's very sensitive to how it's set up and performed and when we set it up,
we spent a lot of time basically dealing with the nonspecific binding issue.
I note that it was in my lab when we
repeated the test that they were essentially all normal and this was a test
that had been licensed from my lab to the Scripts Reference Laboratory while it
was in existence and was commercially available until Scripts Research Institute
sold the reference lab and it was closed and then the test was lost.
I believe that there are problems
now with the -- The only one that I'm aware of that's commercially available
which is the National Jewish Laboratory.
If you talk to other people around the world who do this assay the
general experience is that heredity angioedema patients don't have
auto-antibodies against the C1 inhibitor protein.
I don't think it's a problem really
developing the assay. We noted, for
instance, that how we block the plates after coding is very important and also
the quality of the C1 inhibitor used to coat is very important. If it's degraded, we see increased background
readings that I think can cause a problem.
So it's hard for me to totally answer the question. I think it's not difficult.
The final thing that I would say is
National Jewish and perhaps in response to these problems has reevaluated their
reference standard and has in the last couple weeks, I believe, recalibrated
the assays such that their normal range now would include most of the values
that had been previously classified as abnormally high, not 100 percent of
them, but a good number of them and I think that they're trying at this point
-- They recognize the difficulty and they're trying to improve their assay.
DR. MANNO: As a point of clarification, I think the
antibodies that we're talking about would be classified as
allo-antibodies. That is as a result of
exposure to the therapeutic protein. I
recognize that you said that these are heterozygotes, people who make protein,
but, of course, there are other examples of therapeutic proteins which result
in the production of a functional antibody which neutralizes not only the
pharma protein but the naturally occurring protein. And so we're wondering, I think, if there's a
functional antibody assay that's available.
DR. ZURAW: People have done functional assays and in
fact in the acquired C1 inhibitor deficiency patients, that's one of the types
of tests done to show, in fact, that that was a pathologic antibody. It's unfortunately a very laborious procedure
and I don't believe that there's any clinical lab that would do that. That would be very difficult to do.
The other thing I'd just comment on
is if you consider the European experience where patients really have been
treated multiple times over decades there's no evidence in the literature or in
speaking to the European investigators that the C1 inhibitor replacement
therapy gets less effective over time.
So certainly if we don't believe that there are neutralizing antibodies
which is different than proving that there aren't.
CHAIRMAN SIEGAL: Do we know anything about the sequence
heterogeneity of C1 esterase inhibitor actually from person to person?
DR. ZURAW: There is one common polymorphism which is
valine 458 to methionine polymorphism that has been considered to be a
potential source of inducing antibodies in people getting replacement
therapy. But the C1 inhibitor molecules
just recently in the last year have finally been crystallized and it's
interesting that this amino acid lies in the second Beta sheet which is buried
inside the molecule. It looks to me like
it's not exposed and unlikely to be immunogenic and again I don't think there's
been evidence in the European experience that it's caused a problem.
CHAIRMAN SIEGAL: So really there hasn't been any evidence for
allosensitization.
Question over there.
DR. FINNEGAN: One of the questions would be in the European
group what's the youngest child that they have had on it because the antibodies
in the hemophiliac group appear to be related to the young age at which they
are first exposed to significant doses.
MR. LEVI: I think I can answer that. We do not give prophylaxis to children under
the age of nine or ten years old because they don't need it. They're usually well off with only man
treatment or other types of treatment like we use tranexamic acid instead of
eicosaphentaenoic acid. And our youngest
child to be on regular prophylaxis is ten years old.
DR. FINNEGAN: And, Mr. Chairman, I would think that's
important to consider.
CHAIRMAN SIEGAL: Are there any other comments from the
Committee?
DR. GLYNN: Yes, I just had a clarification also kind of
related to what we just heard. So the
first question, we're being asked for approval.
But approval for what age group?
Pregnancy/no pregnancy? What
exactly is being asked and then that first question can then be clarified by
the FDA, I guess.
CHAIRMAN SIEGAL: Yes, we'll need clarification here.
DR. GOLDING: Well, the first question is asking for if the
data that's presented demonstrates safety and efficacy for prophylaxis and
whether that data could be used as a basis for approval for the prophylaxis
indication. As I said and I think the
sponsor said as well, the indication for on-demand or acute treatment isn't
being discussed today, hasn't been presented and that there are ongoing
discussions with the manufacturer to resolve issues about that different
indication.
DR. GLYNN: Yes. I
don't think you -- I guess my question was not clear. I'm asking for the prophylaxis of the
question you've asked, specifically if you're asking for approval over a
particular age like nine, ten as was just mentioned or if someone is pregnant
or not. It's not clear for me.
DR. GOLDING: Well, I'm not absolutely sure how to answer
that. But I think what we usually do in
the labeling is we make it clear what age groups were used in the treatment and
there's a big emphasis now in the FDA to include pediatric studies and
pediatric labeling. In this particular
case because of some of the issues that you've just heard about, I would expect
that there would be some special discussion about a possible waiver of using
pediatric use. But I think it should
state in the label that this hasn't been tested in, for example, children
younger than nine years of age.
DR. EPSTEIN: Let me just clarify that what's been alluded
to is the requirement for pediatric studies or waivers under the FDA Amendments
Act of September 2007. However, orphan
products are exempted from the provisions of that Act. That doesn't mean that we can't encourage
studies in younger age groups or might not want to. But there's not a formal requirement for the
orphan drug.
CHAIRMAN SIEGAL: I have a question for FDA. Implicit in this trial and included in it
were multiple infusions on an ad hoc basis as open label and it's clear that if
we approve this product for prophylaxis but not for acute treatment that we're
limiting to some extent the reimbursement that would be available to patients
and I just wonder why the distinction has been drawn and whether, in fact, the
previous use in this trial of drug for acute attacks wouldn't implicitly
improve, essentially lead to approval, for acute attacks.
DR. GOLDING: Well, as I said, there are some issues, some
unresolved issues, that we're working with the company to try and resolve in
terms of that indication and I mean the basis for that approval has to be based
again on safety and efficacy and we were working towards that. But we aren't there yet and I would not want
to prejudge what the outcome will be.
But that is where we are today with that.
DR. GLYNN: So can I ask a question about those
unresolved issues? I mean, are these
things that we should be concerned about?
Are they adverse events? Are
these issues impacting somehow what we are evaluating right now?
DR. GOLDING: Well, I think that's an important question
and a difficult question because on the one hand, we have these ongoing issues
that we're discussing with the company and they and we would consider them
proprietary at this time. You know, I
don't want to get into those types of issues.
But from the point of view of this presentation and this discussion, we
think that the prophylaxis trial should be considered as a standalone trial,
that the safety was monitored much more carefully during the prophylaxis trial
than during the acute trial because there were frequent visits to the doctor,
twice a week, to see the patients and we think that safety information is much
more compelling than what was seen during the acute treatment trial.
But we did review and present in the
issue summary, a summary of the acute treatment trial safety signals and we
don't think that the safety in the acute treatment trial shows any signals that
will make us concerned about approving it for the prophylaxis.
DR. APTER: I still share confusion though because the
prophylactic trial was riddled with acute treatment and the public just spoke
about the importance of acute treatment.
DR. GOLDING: So we recognize the importance of acute
treatment as well. But you know when you
look at the data for acute treatment as regulators, we have to have data that's
sufficient to provide information for safety and efficacy. If the acute treatment at the moment is in a
stage where we're discussing those issues particularly related to efficacy that
we haven't yet come to a conclusion about it.
So you could imagine from just a
theoretical point of view without getting into the details of what the issues
are that if you're treating somebody to prevent a disease as opposed to
treating someone who already has the disease and has the extravasation of fluid
and other complications of the disease, it might be a different scenario than
preventing the disease. So you could
imagine, I don't say this is the case, you could imagine where treatment would
be highly effective in preventing but not very effective in treating an actual
attack.
I'm not saying this is the
case. But what I'm saying is there are
issues that we need to resolve with the company before we can come to a clear
cut conclusion about the safety and efficacy for the acute treatment.
CHAIRMAN SIEGAL: Mark.
DR. BALLOW: I would like to open up the discussion about
one of the other questions the FDA wants to ask and that is dose in between
males and females. My gut feeling is and
the sponsor will have to tell me differently that there seems to be a
preponderance of females, perhaps they're being more symptomatic than males,
though the males can go on androgen therapy.
But these studies might be very
difficult to do because of the limited number of patients. You could see there were only 24 patients
enrolled in this prophylaxis study. So I
can't even imagine perhaps doing a dosing study of males versus females. But do we have any further information from
the sponsor for dosing, for example, in
My other impression is that like any
other area of medicine patients will probably seek their own dose. Just like in asthma, for example, they'll go
down on their dose of inhaled steroids to fit their symptomology. So I imagine patients will do that same on using
this medication prophylactically.
They'll seek a dose that helps them stay out of trouble at whatever the
minimum might be.
So it's difficult to answer the
question for the FDA unless we get a little bit more insight about the
availability of male subjects and (2) maybe there's some other data in the
European experience which suggests we do or do not need to do this part of the
study.
DR. SZYMANSKI: A couple of things. I think this reminds me of hemophilia in the
preprophylaxis era and hearing from patients, you know, their state way beyond
the treatment centers and all behooves that at least such a treatment be
started at home because that's what we do in hemophilia. You prevent complications.
And also I think -- a couple of
questions I had. One thing I think is
surveillance should be there not only for after the treatment is given but even
before. I think there is a need to know
who these patients are, I know there is an estimated incidence in prevalence
but I think we really need to know that question. What are the complications? What is the prevalence of this complication?
The question I had was when do you
begin this prophylactic treatment. I
mean, that's a hard debated point in hemophilia. You know, do you do it first joint bleed or
the first intercranial bleed or when do you do that? And I think depending on the age, you know,
why shouldn't it be a child? I mean, you
would let a child go through all these painful episodes before beginning
prophylaxis? I think a child should have
every right to be prophylaxed. You know,
if anyone wants to comment on that, I'd like to hear that.
DR. BUSSE: I actually want to comment on when you begin
prophylactic treatment. As I alluded to
before, we don't really have hard fast guidelines such as we do for some of
other chronic diseases such as asthma.
But really it's a discussion between the patient and the physician and
one of the most important considerations is to ask the patient how their
disease affects the quality of life. So
any patient whose quality of life is severely impacted, even moderately
impacted, should be a candidate for prophylactic therapy.
There are other considerations. One is if the patient has had a laryngeal
attack and that's not even to say if a patient has never had a laryngeal attack
is not going to have one in the future.
So it's an option that should be made to all patients who have HAE
because we don't know if they're going to have a laryngeal attack.
There are patients who have moderate
or severe attacks that require a lot of health care utilization such as
hospitalizations, emergency room visits, ICU stays. Those patients are clearly candidates. Also patients who don't live near a hospital
for whom getting into a car and driving two hours when they have an abdominal
attack, going over bumps in the road, is very painful or even in that two hour
period they can progress to have a laryngeal attack. Those patients are also strong candidates.
As I mentioned before, we give
patients narcotics for abdominal pain and it's really hard probably not to
become dependent on these narcotics. So
in order to prevent dependence on narcotics it's also an important
consideration. So it's a whole, you
know, lots of considerations to take into account when you're discussing this
with patients.
And in regards to the children, a
lot of times children don't have severe enough attacks until they hit
puberty. However, I think prophylaxis
should be made to any child for whom the disease is having severe impact in
missing school, painful, you know, not leading a normal life. So that's why there were fewer kids in the
prophylactic arm because they probably have fewer attacks until they hit
puberty.
CHAIRMAN SIEGAL: Are there any other questions or further
discussion? Yes.
DR. GOLDING: Just to comment on what Dr. Ballow's
question, the intent of the follow-up question that the FDA has was not really
to compare dosing for males and females, but the intent was to look into more
detail in dosing in general and the idea was that when we looked at the
histogram that I presented that the response was more general, and that there
were patients that had modest or intermediate responses and the question is
whether the dosage, the single dosage trial, has led to a conclusion that that
is the correct dosage for everyone and the follow-up studies that we were envisioning
where studies to make sure that that is the optimal dose either for males or
females but not necessarily comparing males versus females.
DR. ZIMRIN: And I think -- go ahead.
DR. GLYNN: I'm sorry.
So I was wondering if we could also change that question 1A, I guess, to
also include age. I mean, it would be
nice to know if a right dose is being used not only by gender but by age and
that's just a question.
DR. ZIMRIN: My question is concerning the variability of
the doses, the lack of a relationship between the dose and the level or between
the level and the symptoms. Wouldn't it
actually be very difficult to conduct a dosing trial? It seems to me that that would be problematic
especially given the relative rarity of the disease.
DR. GLYNN: I don't know if we have a question being
asked is for a natural trial. I
understand it more like Dr. Kulkarni did like a surveillance of what happens
after marketing.
DR. ZIMRIN: Can we get some clarification on that? What does that refer to?
CHAIRMAN
SIEGAL: This is a question for FDA.
DR. EPSTEIN: I think what FDA is putting in front of the
Committee is that the studies left some gaps in our understanding that was it
was predominantly a female cohort and so what would an approval imply for
males. There were uninterpretable
antibody response data and so we're left not knowing if that is or isn't a
significant finding. And this was a
short-term study. You had two periods of
12 weeks and, of course, not every patient completed all 12 weeks.
So what we're really asking perhaps
question two is an essay question. You
know, what do you feel are the gaps in the data that FDA ought to address post
marketing? We're not really putting on
the table a specific design and maybe we need your help to define the correct
questions. But we're just highlighting
that there are gaps in at least these three areas and I think it's been also
made clear from the discussion that appropriate age for prophylaxis is as well
as dosing by age is another gap.
CHAIRMAN SIEGAL: All right.
Mark, you had another question or comment.
DR. BALLOW: No, I mean I think all of us appreciate
those, there's some gaps. But I think
it's going to be very difficult to do that kind of a study because of the
limitations in the number of patients, because of the variability and
correlation of symptoms with the level of inhibitor, et cetera. So I think it would be very difficult to do
that.
CHAIRMAN SIEGAL: Dr. Borish.
DR. BORISH: I don't know if there are too many issues sitting
out here about safety concerns and I just did want to comment that I think the
only reason we're debating whether there were few too many colds or sinus
episodes associated with this drug is because the manufacturer and the FDA when
they designed the study mercifully allowed patients in the placebo to have C1 inhibitor available
to them as a rescue treatment and I'm really brought back to reality by the
public remarks and had these patients not had access to C1 inhibitor, then I
think we could easily be debating whether a few colds is, a few theoretical
colds that nobody really believes this drug causes, is a reasonable price to
pay for the prevented deaths or severe episodes with trachs and everything we
just heard about in the placebo group.
And I, for one, am very satisfied with the safety data from the study.
CHAIRMAN SIEGAL: If there is no further discussion, there
evidently is. Dr. Kulkarni.
DR. KULKARNI: I just wanted to answer Dr. Ballow. I think there is a precedent currently in hemophilia
where there is FDA, CDC and industry involved in a post marketing surveillance
as a public/private partnership. It is
difficult. We understand that, but it's
not impossible. So it is possible to do
that.
CHAIRMAN SIEGAL: Dr. Fleming perhaps will have the last word.
DR. FLEMING: I was just going to comment that issues were
raised about what question two was intending and what we might be able to
do. My understanding of this is that
with 22 patients in the pivotal study, 90 days follow-up, what the FDA has
indicated is there are certain issues that aren't fully clarified. But are the data in question one sufficient
to vote for approval with the idea then that in question two that there could
be studies done and to be defined by the Committee that could be post marketing
active surveillance, passive surveillance, randomized trials to get at longer
term safety issues, rare safety events, longer term efficacy issues, maximizing
dose with respect to children and generalizing efficacy with respect to African
Americans, males, etc. That's my
understanding of what we're being asked to consider.
CHAIRMAN SIEGAL: I think that's everybody's understanding and
I would just like to comment that it seems to me it would be very difficult to
say no to the query in question two.
Well, I think perhaps we're ready to
vote unless there is some objection. So
let's proceed with the first question.
MR. JEHN: Okay.
On the first question, the vote is and again just a reminder, we're
going to vote simultaneously with the raise of the arms and keep your arms up
until I call your name. All right. Dr. Borish.
This is for yeas.
(Roll call vote unanimous.)
It's unanimous yeas.
CHAIRMAN SIEGAL: Let's proceed to question two. Is there any discussion about question two
before we vote?
(No verbal response.)
Then let's proceed to vote unless,
of course, Dr. Fleming has a question.
DR. FLEMING: I was just confused. Is question two a vote or is it more
providing advice as to what the nature of the follow-up study should be?
CHAIRMAN SIEGAL: Yes, I think that's the latter. Anybody have any discussion to that point?
DR. BALLOW: Well, first of all, I think we should break
two down into subcategories. Don't you
agree?
CHAIRMAN SIEGAL: That would be all right.
DR. DI BISCEGLIE: I'd suggest that -- I mean, there's a yes/no
vote to be had and then there's (b) and the substantial discussion already of
some of the issues that might need to be addressed in follow-up studies.
DR. EPSTEIN: I think we don't need up and down votes. We're really just looking for the insights
from the Committee where attention should go assuming we -- If we follow the
Committee's advice with an approval.
CHAIRMAN SIEGAL: All right. So we don't need to vote on
this then.
DR. EPSTEIN: No. So
we have heard a discussion of these issues and I think if there are further
comments on these issues or other issues in areas where the trials may have
left gaps in understanding that are pertinent clinically we'd just like to hear
that.
CHAIRMAN SIEGAL: I'd like to know whether there is a national
registry for this disease.
DR. KALFUS: The HAE Association is very interested in
developing a registry and we've committed to working with them and helping them
so that every patient can be enrolled and asked to participate in registry as
well as every training clinician who is taking care of these patients.
CHAIRMAN SIEGAL: And that might be a mechanism for
surveillance. Question?
MS. BAKER: Well, I would encourage, I would recommend,
surveillance of long-term complications, both physical, social, emotional, cost
of care, much like what we are doing in hemophilia.
DR. SZYMANSKI: As the Director of Blood Disorders, I can
tell you that some of these are Congressional mandates for us to have an
ongoing surveillance for prevention of complications and also this is for all
bleeding and clotting disorders. So
something, I think, a surveillance registry is as good as the information you
put in and if it's voluntary, only those patients who have access to computers
and things like that would put in the data.
So you get a little bit of a skewed idea, but if you want to have a
surveillance of all patients, mild, moderate, severe, whatever it is, then I
think a surveillance system would definitely be far superior and over life span
of these patients. That would be my
comment.
DR. GLYNN: And I agree completely with that. I think an active surveillance system would
be great.
DR. FLEMING: The principal evidence that we've used in
unanimously agreeing to approve has been based in the 22 patients studied over
90 days. I'd encourage the FDA to work
with the sponsor to provide greater clarification about the nature of the
benefit-to-risk profile. Some of this we
could even do even in the pre-marketing setting by probing the data to document
as we've again heard in the open public hearing that reinforce the comments
from Dr. Frank.
The greatest significance here is to
reduce the risk of these most serious events with the sequelae that we've heard
a lot about. What can the current data
tell us about that in terms of efficacy, clarifying the severity of the adverse
events that have been seen to date. But then
in the post-marketing setting, there are important additional insights to be
gained to maximize benefit-to-risk for patients. So having combinations of active
surveillance, passive surveillance and
possibly randomized trials to understand more clearly what are the longer term
safety issues, what are the longer term efficacy issues, what are the rare
events.
The safety data to date seem
encouraging but 22 patients basically are enough to rule out events that would
occur more than 15 percent of the time.
So if there are serious events, the sample sizes still are inadequate to
reliably detect those. So doing
surveillance and possibly randomized trials to understand the rare events, the
longer term safety and efficacy events and issues regarding optimal dosing for
children and expanded insight about efficacy in the under represented
population, African Americans and males, would all be important to benefit the
patient population.
Obviously, the most direct way and
straightforward way is passive surveillance or active surveillance. There might be opportunities to get better insight
from randomized trials. Surveillance is
great if you're detecting huge effects.
If you're looking at detecting relative risks for events that would
occur tenfold as often or more, you can get that in surveillance.
For things that are having, you're
not going to be able to get it in surveillance.
So if doses could reduce the risk of serious events by a factor of two,
but in fact, may induce rare serious events by a factor of two, that's going to
be hard to sort out just by surveillance.
So if it were possible to do a randomized trial by dose in much larger
numbers of patients post marketing, everybody is being treated looking at
whether or not there is a difference over the longer term in benefit and risk,
that would be important insight.
One possibility may not be possible
here, but in some settings one other possible source of randomized trials would
be for patients that have been on therapy for a considerable period of time but
are having substantial attacks.
Randomizing them to best supportive care against continued management
gives another source or another possible opportunity for randomized
assessments.
DR. KULKARNI: I think another plea I have is that since
this is a rare disease one of the things that we could do is harmonize the data
between Europe and other countries and the
MS. BAKER: I would also encourage the exploration of
medically supervised home infusion whereby the family members and/or the
patients themselves can learn how to infuse their medicine. This is rapid treatment and linking that to
reduced complications. That's something
that we've seen in hemophilia for many, many years and that we collect data on
nationally.
CHAIRMAN SIEGAL: And perhaps a study of subcutaneous
administration would be indicated. Are
there any other questions or thoughts?
(No verbal response.)
If not, Dr. Szymanski.
DR. SZYMANSKI: Well, this is sort of not relating to the
latest issues but I would like to ask if anybody knows if there is differences
in gene frequency in various populations of African American, different
European population or Asian, et cetera.
Thank you.
DR.
FRANK: We know that the disease appears
in all populations, but no one has done that kind of study. I mean, we don't even know what the frequency
is in the American population.
DR. GLYNN: I think that's why you need a surveillance
system.
DR. KULKARNI: Complete gene sequencing in a public health
laboratory.
CHAIRMAN SIEGAL: All right.
I'd like if there are no objections to bring this session to a close so
that we can get back here by 1:30 p.m. at the latest to resume. Thank you all for coming.
MR. JEHN: Again, the EVMs are -- The exemplary voting
members are excused. Thank you. Off the record.
(Whereupon, at 12:43 p.m., the
above-entitled matter recessed to reconvene at 1:36 p.m. the same day.)
CHAIRMAN SIEGAL: Good afternoon. Let's come to order.
We are a much smaller group now, and
so we are going to be much more comfortable.
And now we're going to address Topic 3, Review of the Research Programs
in the Laboratory of Hepatitis and Related Emerging Agents, Division of
Emerging and Transfusion Transmitted Diseases, OBRR, CBER.
And this is a site visit that Mark
Ballow, I think, chaired. And is Mark
here, actually?
PARTICIPANT: He'll be here.
CHAIRMAN SIEGAL: All right.
So I guess we should wait for Mark.
PARTICIPANT: It's okay.
CHAIRMAN SIEGAL: You want to go
ahead? All right. Then let's ‑‑ Don suggests that
we proceed.
So we're going to first hear from
Dr. Carolyn Wilson, Acting Associate Director for Research, CBER, on an
overview of CBER research.
Dr. Wilson?
DR. WILSON: Thank you.
So what I'd like to do for you today is to briefly give you an
introduction to CBER, how our philosophical approach is with regards to the use
of research in order to fulfill our regulatory mission, and how we manage our
research programs, and finally, to finish with giving you an idea of how
important the site visit process is in terms of how we manage our research, to
make sure that we are in line with our identified priorities to fulfill our
regulatory mission.
So our mission is to ensure the
safety, purity, potency and effectiveness of biological products, including, of
course, relevant to this Committee, blood and blood products, as well as other
biologics, for prevention, diagnosis, and treatment of human disease, conditions,
or injury.
The vision for CBER is to protect
and improve public and individual health in the U.S., and where feasible
globally, to facilitate development, approval, and access to safe and effective
products and promising new technologies, and to continue to strength CBER as a
preeminent regulatory organization for biologics, and in all cases, to try to
implement the use of innovative technology in order to advance the public
health.
As you can see ‑‑ and
many of you may have seen this many times before, so I apologize if it's
overdone ‑‑ but it does give you a good sense for the range of
products that are regulated by CBER, and it also gives you a sense for how
critical many of our products are to the public health.
Of course, the ones you're most
familiar with are those involved with blood and blood products. But of course, vaccines has a huge impact,
and then we have a number of novel emerging technologies in the area of
xenotransplantation, and somatic cell and gene therapies.
Our approach to regulation is that,
of course, under the umbrella of the laws promulgated by Congress ‑‑
the Food Drug and Cosmetic Act, and the Public Health Service Acts, combined
with regulations, there are a number of factors that we use to implement these
regulations, including external discussion with advisory committees like
yourselves, active research within CBER, review of data submitted to the IND,
and internal CBER discussion, as well, and with all of that, hopefully derive
rational policy and decisions.
But the important point here is that
we feel that, in order to get to this point, active research is a critical
component to support those decisions. So
at FDA, we multi-task. In other words,
the researchers at CBER are fully integrated into the regulatory process,
typically spending about 50 percent of their time doing review, and the other
50 percent running their labs.
And because of that, each research
scientist or research regulator is actively involved in review of INDs, BLAs,
devices, development of policy and guidance documents, meeting with sponsors on
a regular basis, participating in advisory committees, participating in
pre-license and biennial inspections, looking at adverse drug reactions and
risk assessment, and of course, the other component is to actually do research
relevant to product evaluation in order to develop and evaluate scientific
tools and knowledge.
And then, finally, our scientists
also are actively involved in outreach by going to scientific meetings, and
communicating with stakeholders.
Typically, CBER's research are problem-solving. We do both preparation for long-term
programmatic needs, while also being facile, and having an ability to respond
to crises as they develop, and again, having an in-house laboratory program
gives us that flexibility.
We are outcomes-driven. We try to identify and resolve specific
high-priority scientific challenges and product evaluation focusing on critical
gaps and scientific tools and knowledge in order to evaluate products, and developing
research that can support the development of products for critical, unmet
public health needs.
And where feasible, we often
interact in multi-disciplinary coordinated teams in order to fulfill our
regulatory challenges, and oftentimes, this involves, not just internal teams,
but also external, as well.
So this gives you an overview of how
we manage our research programs, and the circle is, arbitrarily, if you will ‑‑
it starts here at number 1 with identification of regulatory and public health
needs, but I have drawn it as a circle to emphasize that it's an iterative
process, and that each step does feed into the other.
And so, after we identify our needs,
from that we identify what should be our research priorities, offices develop
research plans and priorities under these umbrella priorities, and also
evaluate research programs to make sure they are inline with office
priorities. And then again, the outcome
of the research programs often are important in identifying regulatory and
public health needs, and so the cycle begins again.
So to go ‑‑ sorry. The other critical component of this entire
cycle is the external review and input, and we really do integrate external
advice in each of these stages.
So to go in a little bit more detail
in terms of the first step, this involves an analysis of, what is our
regulatory workload, what types of products are being regulated, what types of
products are on the horizon, what are some key policy activities, and what are
some public health and emerging issues?
From that, we get input from all
levels, including all of our staff members, both research regulators and
full-time review regulators, management, as well as external input, advisory
committees being one mechanism for that, along with attending scientific
meetings, participating in workshops, and of course, site visits, as well.
From that, then, as I mentioned, we
develop our research priorities, and we try to focus on things where we feel
that our expertise is uniquely suited to have an impact on facilitating product
development, oftentimes focused on product quality, safety, and efficacy.
And again, the thing that makes us
unique is that we can see across an entire spectrum of product development,
because we see all of the submissions, and so we may identify needs in an area
of product development that an individual sponsor may not.
So to give you an example of CBER's
research priorities for FY08, this is a list that was developed by the CBER
Research Leadership Council. This is
made up of CBER management, including associate directors for research from
each office, as well as full-time reviewer regulators.
And the first is to improve or
develop new methods to measure and augment biological product safety and
efficacy; to evaluate, develop, and integrate novel scientific technologies to
improve biologics product regulatory pathways, availability, and quality;
facilitate the development of new biological products for high-priority public
health threats, including pandemic flu, emerging infectious disease, and agents
of bioterrorism; improve clinical trial design and evaluation, including
adaptive design approaches; develop formal risk management and risk assessment
approaches; and enhance safety surveillance by developing improved analytical
tools, and accessing large databases.
Some examples of CBER's research
that have been identified as high priority this year, and that's in the form of
receiving targeted funds for the critical path initiative, one from each
office, just to give you an example, from Office of Biostatistics and
Epidemiology, a project to analyze health care databases. This is to increase the sensitivity of
detecting rare adverse events associated with post-marketing approved products.
Office of Biologics Research and Review, using proteomics to identify
biomarkers predictive of stored red blood cell and platelet efficacy; Office of
Cellular Tissues and Gene Therapies to improve the safety and efficacy of
adenovirus specters for gene therapy; and Office of Vaccines is a project to
develop an in vitro method that can predict in vivo toxicities of novel vaccine
adjuvants. So that gives you an idea of
the types of projects that we would view as high priority.
So once our research priorities are
identified, offices then develop research plans and priorities. This involves, again, the same type of
information gathering, except now at the office level. In addition to those aspects is also the research
program review and evaluation.
And so that actually has two different
aspects. One is the internal review
that's done at the office level to look at whether or not the projects are
relevant to the office priorities, are of high quality, and are of reasonable
productivity. And then the other, which
you are here today to discuss an example of, is a four-year research program
evaluation by an external site visit.
And then internally, we also include
a Promotion, Conversion and Evaluation Committee that also does cyclical review
for personnel actions. So then that is
incorporated into the office research plans and priorities.
To just go into a little more
detail, the annual review of research programs is collected ‑‑ the
information is collected on web-based research reporting, where we collect
information about the achievements, and those are rated for quality,
productivity, and impact on the regulatory mission, so it includes scientific
publication, relevant guidance documents, presentations at scientific meetings,
workshops, and advisory committees, as well as some information about the
future plans. And those are looked at
for the quality, feasibility, and again, relevance to office priorities. And these are then reviewed by office
leadership.
The site visit is critical for
external review, and these typically are reviewing each laboratory unit, so the
research reviewers, as well as their research programs, are reviewed in the
context of their entire lab.
They prepare and submit detailed
material. Any of you who have served on
site visit committees are familiar with this process, and these materials
include both the achievements from the past four years, as well as a proposal
for the research for the next four years.
It culminates in a day of formal
presentations of the site visit team, as well as individual interviews with
each PI. And that site visit team then
drafts a report, which is presented to the parent advisory committee for
approval, and that's what your committee is doing today.
Internally, we also have a mechanism
for cyclical evaluation. All research or
regulatory staff are evaluated by this committee that's composed of senior
research or regulatory, as well as full-time review scientists from each
product office.
The review includes both an
assessment of the individual's regulatory workload and their ‑‑ and
the quality of their work, as well as their research, productivity, relevance,
and quality. And the package includes,
among other things, the site visit report.
So the output of that evaluation is critical to that individual's
evaluation internally, as well. And
then, the PCE provides recommendations to me, and then actions are made.
So finally, I just wanted to finish
with a quote from the FDA Science Board Subcommittee on Science and
Technology. They released a report in
November of 2007. You may be familiar
that the Commissioner had tasked them with the review of all FDA science, and
this quote indicates that CBER has a rigorous process for establishing
priorities and impact of Center research on regulation. In addition, leadership of CBER insists upon
integration of laboratory scientists, both in the review, and manufacturing
site inspection.
But importantly for today is
external peer review of research programs is the norm rather than the
exception, and the point here is that that is something that was considered a
key component of our good research management program.
So finally, I wanted to finish by
just thanking you for your time, expertise, and input into our research
programs. As I said, this is a really
critical component to our ability to maintain high-quality research that's of
relevance.
Thank you.
CHAIRMAN SIEGAL: Thank you, Dr. Wilson.
Are there any questions for Dr.
Wilson?
PARTICIPANT: We'll do those at the end.
CHAIRMAN SIEGAL: At the end, okay.
The next speaker is C.D. Atreya,
Ph.D., Associate Director for Research, who will give us an overview of OBRR
research.
DR. ATREYA: Good afternoon, everybody, and thanks for
Carolyn for having a good introduction of the CBER programs, which makes my
life a little easier, because I do not need to show what CBER does. But there may be some overlapping slides, and
please bear with me on that.
So in general, I would like to
present a little brief overview of our office ‑‑ that is, the
Office of Blood Research and Review. I
will give you an overview of the organizational structure, and then I will talk
about the regulatory responsibilities of the office, and how we are managing
our research programs in the context of CBER management research initiative,
and also, what are our current research priorities.
The structure of our organization
office level is, as you all know, Jay Epstein is our Director, and we have a
Deputy Director, Jonathan Goldsmith, and then we have three Associate
Directors, one for Research, one for Regulatory Affairs, and one for
Policy.
And then, under this office, we have
three divisions, and the division is ‑‑ one of them is the Division
of Emerging and Transfusion Transmitted Diseases, and the second one is
Division of Hematology, and the third one is Division of Blood Applications.
And the first two divisions also
have their research components. That
means they have the labs in their divisions.
This is just to show you the vision
for CBER. Since Carolyn already showed,
the only difference here is that the innovative technology, advancing public
health, is at the bottom of the slide in that one, and then here we have it on
the top of it. So it's essentially the
same thing. I am not going to repeat
what she said.
So coming back to what are the OBRR
responsibilities, OBRR is one of the primary ‑‑ the only component
of FDA that deals with, you know, facilitating development, approval, and
access to safe and effective blood products.
That means it involves a lot of IND-type product application reviews,
inspections to the pre-license of sites, standards development, and so on and
so forth. A lot of things happens.
And we also evaluate promising new
technologies related to blood and safety of retroviral testing, and what comes
with that is also that we are charged with regulating blood and blood
derivatives and derived products, medical devices used to collect, test,
process, store donated blood. And we
also engage in retroviral diagnostic tests.
As you saw, those three divisions
were there before, and the product responsibilities for regulation actually are
different for different divisions. And
the Division of Emerging and Transfusion Transmitted Diseases has the
responsibility for blood donor screening tests for infectious agents, and also
retroviral diagnostics.
The second division, that is, the
Division of Hematology, has plasma-related products that ‑‑ meaning
like immunoglobins, and albumin coagulation factors and products, et cetera;
and the blood and blood component collection devices; plasma expanders,
including hemoglobin-based oxygen carrier solutions; and also, bacterial
detection devices.
And the third division, that is, the
Division of Blood Applications, does not have the laboratory component, but
they do equally important work that is ‑‑ you know, they go for the
blood and plasma licensures, blood establishment computer software review, and
blood grouping and auxiliary agents.
So these are the product
responsibilities lying in these three different divisions.
Just coming back to critical
path/FDA mission, because we are engaging in ensuring the public safety, FDA
has its critical path mission four years ago, published it like a report, and
everybody is aware of that. What it is
is that early on, that is, starting from the basic research, there are several
steps in developing a product that comes to the market and the approval.
The basic research prototype design
and discovery, clinical development, and then FDA filing, and for approval
process. So this ‑‑
somewhere between basic research, and that, you know, goes into the next stage
of product development, and design, and discovery, up to the approval process,
FDA calls that as a critical path.
And we ensure that, by working with
the industry -- actually, we encourage industry and sponsors to come and talk
to us somewhere early in the process, so that we can work with them all through
this process, and try to make it a seamless process at the end towards
approval, so that we are all on the same page. So that is the critical path mission.
And as a result of this ‑‑
FDA's critical path mission, we also need to have an active research component,
as Dr. Wilson mentioned before, and that is our high priority. So with that, I will turn to page two, how we
are managing our research programs, and how we identify key scientific needs.
One way of looking at it is that
simply by horizon scanning. What I mean
by that is we actually look into the anticipated regulatory science needs by
analyzing the recent one- or two-year product applications submissions, and
public health needs, and policy portfolio, and regulatory review workload by
product class, guidance documents, and analysis of product failures and safety
reports, and observations that we do at inspections, and input from scientific
workshops and meetings, and also interactions with regulatory industry, other
HHS components, and international partners, such as WHO.
And then what we do is, based on
these evaluations, identifying these needs, we also try to research ‑‑
I mean, they are targeted to specific identified needs where actually our
contribution will make a difference in our regulatory barriers, to overcome the
barriers, then, to product development.
So based on this evaluation process
and horizon scanning, we identify scientific needs, and we also look internally
for the available resources and expertise, and sometimes with collaborations
from outside. And we look for the
feasibility and success of public health significance and expected outcomes for
that research program.
And so based on these criteria,
currently OBRR has six high priority areas for the research programs, and they
are ‑‑ one is, as you all heard, novel methods of pathogen
reduction in activation in blood and blood products, and the second component
that is ‑‑ I highlighted, because today's laboratory program has
something to do with that. That is,
multiplex platforms, and high-sensitivity methods for pathogen detection,
including genetic variant, and, you know, emerging infectious diseases and
bioterrorism agents.
And the third one is the development
of infectious agent panels for assay standardizations, and standards and
reagents for product and lot release testing.
And the fourth one is development and evaluation of proteomics and
genomics-based biomarkers for efficacy, quality, toxicity, and consistency of
blood components, blood derived products, and their analogs.
And the fifth one is development of
predictive models for ‑‑ including animal models, for pre-clinical evaluation
of blood components, blood derivatives, and their analogs, and to also study
pathogenesis of blood-borne infectious diseases agents.
The sixth one is the development of
methods to evaluate efficacy of immunoglobins that are important, like pandemic
and BT importance.
So with that, I just want to leave a
slide for you that, what is Division for Research in OBRR? You have seen division for CBER, and in line
with that, what we do is support critical path for product development through
focusing on scientific questions critical to the effect of regulation, and
concentration in areas where our unique role as regulators is most
contributory.
And then, provision of an
infrastructure for the investigation of product limitations and failures, and facilitation
of progress towards the goals and promise of 21st century medicine. Examples are genomic and proteomic-based
medicine, nanotechnology, et cetera.
And in conclusion, what I can say is
that, actually, research is integral to the mission of OBRR, CBER, and largely
for FDA. And OBRR research definitely
facilitates product development, and is aligned with FDA small critical path
research.
Thank you.
CHAIRMAN SIEGAL: Thank you, Dr. Atreya.
The next speaker is Hira Nakhasi,
Ph.D., of FDA, giving us an overview of the Division of Emerging and
Transfusion Transmitted Diseases' Research Program.
DR. NAKHASI: Thank you very much. You heard, first of all, the CBER vision,
which is 30,000 feet up above, and then you went to the office level, which is
around 20,000 feet, and I will give you an overview of our division, which is
at the 10,000 feet, and then you will hear what's on the ground happening. After me, then Dr. Gerardo Kaplan will give
you what we are doing at the moment.
So just to give you an overview of
the Division of Emerging and Transfusion Transmitted Diseases ‑
abbreviated form, we call it DETTD ‑ so the organization as ‑‑
you know, first things first, that the ‑‑ it is the immediate
office, and then there are four branches in the division.
Three of them are the research
reviewer branches, and the one which is here, which is the Product Review
Branch, which is usually ‑‑ in this branch, people ‑‑
100 percent reviewers, and in these ones, it's 50/50, which Carolyn mentioned early
on.
However, you can see they are all
connected among themselves, because there is a close collaboration going on
between the full-time reviewers, and the research reviewers. And today's site visit report is ‑‑
I think my eyes are fading out. I think
this is the one which is the Dr. Gerardo Kaplan's lab, which is going to be
reviewed.
The mission of the division is to
plan and conduct research, pathogenesis, and proof of concept for the
development of assays for agents such as viral ‑‑ basically, all
blood-borne agents for viral, parasitic, DSC, and bacterial agents. And also, there is a small component which
also takes care of some of the ‑‑ which is a CBER priority for the
development of biomarkers for blood-borne parasitic vaccines.
We basically proactively ensure the
safety of blood products through reviewing of the applications for these test
kits, which come for these agents. We
evaluate new technologies for these kind ‑‑ detection of such
things, and we develop guidances for implementation of those test kits, as well
as the other component, which is the retroviral diagnostic kits.
In addition to that, we also ‑‑
there is a strong component in the division, which is taking care of the lot
release testing, any lot of these test kits, which, before going to the market,
they are evaluated in-house in the laboratory, and we develop reference
standards for these lot release materials.
And then, we conduct inspections for
the manufacturing facilities, make sure these products are made under GMT
conditions, and we also consult with the outside components, such as the PHS
agencies, as well as, also, other blood establishments as a liaison.
And outreach basically is our ‑‑
our outreach is basically trying to seek advice from committees like today, or
from TSE Advisory Committee, or Blood Safety Availability Department, which is
under the Department of Health and Human Services.
The research output for the fiscal
year '07 from the division, there are 11 principal investigators in the
division, and a total of ‑‑ which are supported by a total of 54
FTEs ‑‑ that's full-time employees.
These include technicians, the staff, and the visiting associates. And then, the output for last year was 32
publications in peer reviewed journals.
In addition to the regulatory output
for the fiscal year, we reviewed a number of BLAs, biological license
applications, dealing with the test kit, their supplements, pre-market
application, their supplements, 510(k)s, INDs, and IDEs. We tested lots of test kits before they were
released. We performed a number of
investigations, inspections, as well as the laboratory investigations.
So the important ‑‑ as
Dr. Atreya mentioned to you that the ‑‑ our focus in the division
is basically this critical path challenge for blood products. What is the critical path for our
division? It is to enhance product
safety, purity and potency, in order to avoid shortages and measure cost
increases. So they are interconnected to
each other. So we need to focus on that.
So, what is our impact on the public
health? As you know, millions of units
are transfused annually, and risk of transfusion through transmission ‑‑
sorry, transmission through transfusion has significantly reduced with the
introduction of tests.
And this is, just to give you an
example, the risk of transfusion transmission of these agents has significantly
decreased once the tests were introduced, for example, Hepatitis B, Hepatitis
C, and HIV, in the
Recently, many of you know that
since last ‑‑ since 2003, blood establishment introduced screening
for the West Nile Virus, and because of that, you know, we have interdicted
around 2,600 West Nile NATs to sample donors ‑‑ donations, which
would otherwise have gone into the recipients, and in that, which translates
into these components.
And with the introduction of this
test, we have now last year zero transmission ‑‑ transmission
cases. So therefore, again making a very
strong impact on the safety of blood supply.
Recently, in the last ‑‑
in 2007, the blood establishment introduced the antibody test for T. cruzi, and
this is a slide from ‑‑ courtesy of AABB, and they have
interdicted, from around 12 million donations, approximately 1,500 repeat
reactives, and something like 500 cases were positive donations, which would
have otherwise gone into people. So
again, improving the blood safety.
So, but then there are challenges
still. You know, we cannot sit on our
laurels, because, you know, we ‑‑ every time we do make blood safe,
there are new things coming up. So our
challenges are ‑‑ both scientific and regulatory challenges, are in
the areas where new emerging pathogens threaten the blood supply. For example, HIV drug resistance, recombinant
variants, HPV mutants, and also to make sure the tests which we have now
licensed are able to detect those agents.
So we have to be vigilant all the time.
So, and similarly, we have to be
looking at emerging pathogens to be on the horizon ‑‑ for example,
Dengue, Chikungunya, bioterrorism agents, and SARS-Corona Virus was in
Similarly, there are significant
donor loss because of the exposure to, for example, some of the parasitic and
TSC agents. At the moment, we don't have
any screening assays available for such, because existing ‑‑ for
existing parasitic agents, such as malaria, Babesia, Leishmania, TSC agents,
and there are some tests out there for ‑‑ because certain people
are different, and because of the exposure, or there are not supplemental tests
available.
So we need to be cognizant of that,
and we are ‑‑ those are our challenges, how we can get those things
on the market.
So therefore, the challenge for us
is to evaluate these assays, which are always being improvised on the
sensitivity and specificity, so that we can detect their variants, or the
mutations of these agents.
We
should maintain the safety of blood supply by assessing the efficacy of
screening and diagnostic tests in the detection of these variants, for example,
and to make sure that we, in-house, have proof of concept for some of these
gaps in the knowledge ‑‑ for example, screening assays for ‑‑
and the pathogenesis of emerging viral, parasitic, and TSC agents, and BT
agents.
With that, I want to thank you for
your attention, and I will ask Dr. Gerardo Kaplan to give his outlook on his
research program.
Thank you. Unless there are questions, I can ‑‑
CHAIRMAN SIEGAL: Thank you very much. We'll do questions at the end of the
presentation.
DR. KAPLAN: Okay.
Good afternoon. I'm Gerardo
Kaplan, Chief of the Laboratory of Hepatitis and Related Emerging Agents. And today, I will give you an overview of our
site visit that occurred in 2007, and was chaired by Dr. Ballow.
My lab ‑‑ the mission of
my lab is to regulate blood donor screen tests for Hepatitis viruses. And we conduct research in support of our
regulatory mission.
My lab has two groups. One is ‑‑ focuses research to
Hepatitis C and SARS-Corona Virus, and is headed by Dr. Taylor. This group is ‑‑ Erica
Silberstein is part of the staff scientists in the group. Mr. Chin is a biologist, and Mr. Plant ‑‑
Dr. Plant is a staff fellow, and Mrs. Ulitzy is a pre-doctoral fellow.
In my group, we work mainly on
Hepatitis A virus and fetal viruses. And
Dr. Hsia is a staff scientist, Dr. Konduru is a visiting scientist, and we have
two post-doctoral fellows in the lab.
So the objective of the site visit
review was to review the conversion of Dr. Silberstein and Dr. Konduru to staff
scientists at the level of GS-13, the conversion of Dr. Taylor to senior
investigator at the GS-14 level, the promotion of Dr. Hsia to staff scientist,
and a cyclical review of my research.
There were five presentations, and
in the interests of time, I will only highlight the major points of each
presentation. Mine was the first, and my
group works in Hepatitis A virus serial receptors, and the role in viral entry
and immunoresponses.
And a few years ago, we identified
the Hepatitis A serial receptor. It was
a normal molecule at that time, and we studied its interaction with the
virus. A few years later, it became
apparent that the natural function of these receptors, or the family of
receptors, they are very important regulators of immunoresponses.
And specifically, the HAVCR1, it's
the receptor I ‑‑ the name I put to the Hepatitis A serial
receptor, has an important T‑helper 2 effect. More interesting, there's a wealth of
evidence that Hepatitis A virus infection ‑‑ that there is an
inverse association between Hepatitis A virus infection and development of
allergy and asthma. And the Hepatitis A
receptor is the molecular link between these diseases.
So in 2001, from work from
Interestingly, the Hepatitis A
serial receptor, I discovered a few years earlier, is the orthodox of TIM1, and
the pattern of expression is pretty similar in mouse and humans.
The exact function of HAVCR, TIM1,
is not ‑‑ is not known, and is the focus of my research as part of
the ‑‑ what I will tell you in a few minutes. TIM3 and TIM4 are the orthodox of the mouse ‑‑
TIM3 and TIM4.
So one of the ways to understand how
a ‑‑ what is the natural function of these receptors, is to
identify ligands. So what we did is an
expression cloning strategy, which instructed cells with a cDNA library of
lymph node, and we identified a clone, this is Clone 1, that binds specifically
to cells of ‑‑ bind specifically to HAVCR, but do not bind to a
control receptor.
So we then identified the human
molecule that was in the cells, and we identified that IgA was binding to the
HAVCR1. So IgA is a natural ligand of
this receptor.
We then wanted to verify what is the
impact of binding of IgA to the receptor in viral cell entry, so we have a
receptor neutralization assay. We mix
the virus with a receptor, and it is neutralized. The level of neutralization here is about a
log and a half. This is with the
control. This is with the receptor, HAVCR1.
If we put IgA, it's about the
same. However, if we put ‑‑
sorry, if we put IgG, it's about the same.
However, if we put IgA in the mixture, there's a high increase. So, there's a synergistic effect of this
interaction.
Then, we wanted to know ‑‑
analyze what is the impact ‑‑ the biological impact of the
interaction of HAVCR with IgA, and we found that monocytes which have IgA at
the cell surface would be activated when we treat it with several forms of
HAVCR.
Moreover, when we put these
monocytes in contact with T-cells, there was a proliferation of T-cells. And you can see it here. With media, or with the control, there is no
proliferation. With HAVCR, it's a
considerable proliferation. And here are
pictures of how the lymphocytes are growing.
They like to see the activated monocytes.
We recently discovered that TIM1 and
HAVCR1 are also receptors for phosphatidylserine, which is a lipid which
normally is presented in the inlet part of the plasma membranes. And here you can see a blood with ‑‑
spotted with different lipids, and HAVCR and TIM4 bind specifically to this one
‑‑ phosphatidylserine.
And this has important implications
in aproptosis, because when ‑‑ once cells start ‑‑ from
death, one of the first markers is the flipping of phosphatidylserine from the
inside leaflet of the membrane to the outside part.
We did some structural analysis, and
this is the structure of TIM4. And we
knew that they form a cavity with an ion-binding domain. This is a cocrystal of TIM4 with
phosphatidylserine, showing that phosphatidylserine binds perfectly here, and
coordinates into this cavity.
So as a summary of the work I showed
you in Hepatitis A, IgA ligands of HAVCR.
The interaction of HAVCR with IgA has a synergistic effect on
virus. The activation of
antigen-presenting cells by HAVCR1 may modulate TH2 responses involved in the
development of allergy.
I did not show you that HAVCR binds
to itself in a hemophilic interaction.
And I showed you some data showing that HAVCR and TIM1 are
phosphatidylserine receptors, and this may be very important to regulate
immunoresponses by uptake of apoptotic cells.
The next presentation in the site
visit was by Dr. Konduru, who works in my group, and he ‑‑ the
focus of his work is mainly to understand the terminus of Hepatitis A virus
growth and pathogenesis, and also he has a project developing ebola virus reagents
for diagnostics vaccine evaluations.
Wild-type Hepatitis A doesn't grow
well in cell culture. It doesn't grow at
all. And when you try to adapt it, there
are accumulated mutations. These
mutations attenuate highly the virus.
This is a very important problem for diagnostics, because you cannot
isolate the virus from the environment, or clinical samples.
And also, it's a very important
problem for research, because this ‑‑ it's very difficult to
understand what are the hepatic virulence determinants of this virus. So Dr. Konduru, in the lab, tried to resolve
these problems, and what he did is he developed an expression factor of
Hepatitis A. He cloned a polylinker, and
then inside this polylinker, in the genome of Hepatitis A, he cloned different
resistance markers.
And what he found out is, when he
transfected this construct with the resistant markers, only the one having
blasticidin will grow, and so now we have a vector that we can select for using
antibiotics. And it's a very efficient
selection process.
So Dr. Konduru used this approach to
isolate cells that will support the growth of wild-type Hepatitis A virus. So he transfected hepatoma cells with the
construct bearing the blasticidin vector marker. He then selected cells with blasticidin. The cells that survived grew in there, and
here's an immunophoresis analysis of that.
It's inside the blastic fluorescence.
And then, he was able to cure these
cells, treating the cells with interferon Alpha. So now we have, in the lab, a cell line that
allows the growth of wild-type Hepatitis A virus, and we can use it for
diagnostics, and to understand ‑‑ to derive viruses that have a
wild-type phenotype, and some attenuated mutations or deletions to understand
the process of hepatovirulents.
So in summary of his work in
Hepatitis A, he developed full-length HAV vectors containing blasticidin vector
marker, isolation of hepatoma cell lines that allow the ‑‑ support
the stable growth of wild-type Hepatitis A virus and cell culture. And this I didn't show you because of lack of
time ‑‑ selection of mutant cells replicates very fast, and this
can be used for vaccine production.
The other project that Dr. Konduru
is involved in is in developing reagents for ebola virus, and so ‑‑
ebola virus is part of a family of viruses called filoviruses, which are
category bioterrorism agents, and there are no licensed vaccines or effective
treatments against these diseases. So
it's very important to develop diagnostic tests, and try to understand how the
protective immunity develops.
So there are negative stranded virus
enveloped. One of the genes is the
glycoproteins, which are the spikes here on the particle. And the virus uses this glycoprotein to enter
the cell, at least part of the inter-mechanism of ebola is glycoprotein.
So what Dr. Konduru did is to
express fission proteins of different form of the glycoprotein, purified
homogeneity, and here's a form called GP1, here's another form with GP1/2, and
there's solo a form, and derived monoclonal antibodies against the GP1/2, which
we are using for developing a diagnostic assay and to understand epitopes of ‑‑
protective epitopes.
In summary of his work, so he
produced some work with the retrovirus celltypes with ebola virus to do the
analysis of monoclonal antibodies. He
purified a number of forms of the ebola virus glycoprotein, developed a panel
of monoclonal antibodies against the glycoprotein, and used these monoclonals
for diagnostic purposes and vaccine evaluation.
The next presentation was by Dr.
Hsia in my group, and Dr. Hsia's work focuses mainly on Hepatitis B virus in
blood safety. And she has a series of
very interesting projects that they have a good impact, regulatory impact.
So one of the projects is to compare
sensitivity of Hepatitis B virus surface antigen and nucleic acid test for
donor screening. She has participated in
development of WHO standards for HPV NAT.
She determined the minimum effectivity dose for Hepatitis B, established
the Ochol Hepatitis B and Hepatitis B mutants, and developed a diagnostic test
based on oligonucleotide arrays.
I will highlight two of her
projects, the first one and the fifth one.
So in this project she correlated serology tests with NAT tests for
Hepatitis B virus, and she finds a series of tests which at the time were
investigational, were not licensed, which they were very sensitive. They detected very low levels of Hepatitis B
DNA at the cut of the serology values.
So this has had very important implications in terms of the regulatory
connotations of the licensing of these tests.
The other project that she was
involved with in developing a oligonucleotide microarray that could detect
simultaneously several pathogens, and she focuses on HPV, HCV, and HIV, and
here you can see that in a positive plasma sample for Hepatitis B it detects ‑‑
it lights up here with their probes against Hepatitis B, but it doesn't light
up in other parts where a probe for HIV for HCV, and this is a control part ‑‑
a panel showing that the oligos are present and these in yellow are hybridizing
with internal control plus the HPV.
And she has proved that she can
simultaneously detect these three blood pathogens at a very high sensitivity
level.
Next talk was by Dr. Taylor, and so
her program mainly focuses on the study of SARS and Hepatitis C. On the SARS area, she studies viral
inactivation, development of an animal model that mimics human disease, and
pathogenesis of SARS. And one of her
experiments has been with inactivation of SARS virus with solvent/detergents. And you can see here that about six hours she
gets a pretty good level of inactivation of the virus with solvent/detergent
treatment.
Another of her projects is
development of vaccines against SARS, and this is inactivated vaccine. She used a ferret model. The ferrets were vaccinated and then boosted,
and then they ‑‑ these ferrets developed levels of neutralizing
antibodies, and after challenging the development of antibodies ‑‑
and this response was protected from disease.
In summary of her studies for the
ferrets, one important aspect was that there was no evidence of
antibody-dependent enhancement of disease, no evidence of disease symptoms such
as coughing and sneezing, some elevated temperatures and ALTs, lung lesions
similar to human pathology, and this was the first publication showing lung
histopathology after SARS infection.
On her HCV program, Dr. Taylor
focused mainly on the effects of interferon in replication of Hepatitis C, and
one of the path ‑‑ interferon pathways, one of the gene-activated
is ADAR1, and what Dr. Taylor has found is that if she knocks out ADAR
expression here with siRNAs, ADAR expression here, she uses siRNAs, the
expression goes down. At the same time,
there is a good stimulation of replication of HCV replicon.
Dr. Silberstein, that works with Dr.
Taylor, gave the next presentation. And
her work focuses on VA RNA, and the effect of VA RNA on inhibiting ADAR. And let me tell you, VA RNAs and
adenoviruses/siRNA is expressed in the expression in ‑‑ is expressed
at late phase.
So what Dr. Silberstein did is he
transfected VA RNA into cells that were infected with HCV, and what she found
is that there is a good stimulation of replication after transfection with VA
RNA.
More interesting, when supernatives
from these cells ‑‑ when she infected the hepatoma cells with
supernatives of these cells, she found some cytopathic effects that is being
right now studied.
A summary ‑‑ so serum
derivable type Hepatitis C replicates in hepatic and non-hepatic cells if VA
RNA is present. Hepatitis C groups 1A,
1B, and 2A replicates in Vero cells.
Vero cells can support the growth of a cytopathic virus. VA RNA can hep establish persistent
infections of HCV, and Hepatitis A replicates in Vero cells which were boosted
with VA RNA.
In summary of the whole site visit,
so what I told us that LHREA developed missionary-oriented research programs in
Hepatitis A, Hepatitis B, and Hepatitis C.
Additional research programs in Filoviruses and SARS-Coviruses ‑‑
Covirus were developed in support of counterterrorism and emerging infectious
diseases initiatives at CBER.
And the research programs are the
basis ‑‑ are basic and applied and support the regulatory mission
of our lab.
And with that slide, I would like to
conclude my talk and ask, if you have any questions, we would be happy to
answer them.
CHAIRMAN SIEGAL: Thank you, Dr. Kaplan. The floor is now open to discussion.
DR. DI BISCEGLIE: Gerardo, I guess I'm ‑‑ this is
very nice. I'm curious as to how you coordinate
Hepatitis research with other labs doing Hepatitis within CBER. So I know of at least one other, and maybe
there are others that I don't know of.
So is there some coordination that is going on in other divisions?
DR. KAPLAN: Yes, there is ‑‑ they are. And for instances I come from the Feinstein
Lab. I was hired by Steve Feinstein,
which is the vaccines and then I moved to OBRR where I am right now. And so we have collaborated a lot on the HAV
arena.
On the HCV, this other lab in OBRR
by ‑‑ headed by Mei-ying Yu, and here is an active collaboration
between Debbie Taylor and Mei-ying Yu and Steve Feinstein. I would like to mention also that Debbie
comes from Steve Feinstein. So there is
a good integration.
DR. DI BISCEGLIE: My other question is about Hepatitis E virus.
DR. KAPLAN: Yes.
DR. DI BISCEGLIE: You may have seen the paper in the New
England Journal about a month ago, which I think was the first demonstration
that -- of chronic HEV infection in
post-transplant people. And, you know,
we think it's a zoonosis about 10 percent of the
My question to you is whether the
agency ‑‑ any branch ‑‑ has made any assessment of the
risk of Hepatitis E virus to the blood supply, and whether it's a focus of
research in any lab that you are aware of.
DR. KAPLAN: Okay.
We scan the horizon, as Hira said, and we try to be aware of what is
going on in the Hepatitis world of infections.
We do not have a HEV program, and I think with the level of funding that
we have we can just maintain what we have.
And most of our programs get funded
from outside sources. So I think it's
important. I think that we need to keep an eye on it. There is no other component that I know of that
are ‑‑ is working in Hepatitis E.
If it really becomes a problem for transfusion, I think that we will
have to reevaluate it.
But we are pretty maxed out of ‑‑
on resources and ‑‑
DR. DI BISCEGLIE:
I understand. But
just to persist a little, you know, I have never been concerned about HEV as a
blood ‑‑ as a threat to the blood supply until this demonstration
of chronicity. And, yes, in
immunosuppressed individuals, but it maybe doesn't need a research program, but
it needs some vigilance perhaps, because, you know, where is this 10 percent of
the population getting infected from? We think it's zoonotic: animals, pigs,
and so on. But, you know, is there any
risk to the blood supply?
DR. KAPLAN: Yes.
We'll keep an eye on that. But
from that to development specific program before we can see a real program in
the
DR. NAKHASI: Okay. Thank you. This is Hira Nakhasi. I just wanted to make a comment ‑‑
Carolyn reminded me ‑‑ that there is a Hepatitis E program in NIH, and
if need arises we always get, you know ‑‑ seek their advice. And as Gerardo mentioned that, you know, we
always keep horizon scanning and make sure ‑‑ and when and if it
becomes blood-related issues, some transfusion transitive, we will be focusing
on those areas. That's how we allocate
the resources, as you said -- as you heard Dr. Atreya and Dr. Carolyn Wilson
talking about the priorities. And every
year we assess that, and how those priorities will change. So I just wanted to make sure of that.
CHAIRMAN
SIEGAL: Yes?
MR. TROXEL: I was just wondering ‑‑ rapid
testing for HCV and Hepatitis B, is that something you see in your lab? Do you have manufacturers out there looking
for the FDA to look at these products?
DR. KAPLAN: It will be something similar to HIV for
diagnostics. We do not regulate
diagnostic tests. We regulate blood
donor screening tests. That's the
difference between the retrovirus program and the Hepatitis program.
The diagnostic tests are regulated
at CDRH, which is another center. So I
couldn't tell you if they have applications for rapid tests. My guess would be that they do.
DR. NAKHASI: Again, I just wanted to make sure that you
understood correctly. Under some
agreement two years ago, the -- only the HIV, which is the retroviral,
diagnostics will be regulated by CBER, whereas all Hepatitis and other
diagnostic tests will be regulated by CDRH, so, therefore, those assays are not
under our purview.
CHAIRMAN SIEGAL: Mark, do you have any comments on this?
(No response.)
Are there any other questions?
(No response.)
Well then we have questions. We have the open public hearing. Is there anyone who wishes to speak at the
open public hearing?
(No response.)
Absent that ‑‑ all
right. Then, we will take five minutes
to clear the room, because the next part of the program is a closed
session. We can take a break in that
five minutes.
(Whereupon, at 2:36 p.m., the
proceedings in the foregoing matter went off the record.)