UNITED STATES OF AMERICA
+ + + + +
FOOD AND DRUG ADMINISTRATION
CENTER FOR DRUG EVALUATION AND RESEARCH
+ + + + +
ENDOCRINOLOGIC AND METABOLIC DRUGS ADVISORY COMMITTEE MEETING
+ + + + +
TUESDAY,
OCTOBER 7, 2003
The Advisory Committee met at 8:00 a.m. in the Versailles Ballroom of the Holiday Inn, 8120 Wisconsin Avenue, Bethesda, Maryland, Dr. Michael McClung, Acting Chairman, presiding.
PRESENT
MICHAEL McCLUNG, M.D. Acting Chairman
HENRY BONE, M.D. Consultant (Voting)
THOMAS O. CARPENTER, M.D.Member
DEAN FOLLMAN, Ph.D. Member
BARBARA LUKERT, M.D. Consultant (Voting)
CLIFFORD ROSEN, M.D. Consultant (Voting)
DAVID SCHADE, M.D. Member
MORRIS SCHAMBELAN, M.D.Member
MARTHA N. SOLONCHE Consumer Representative (Voting)
PAUL WOOLF, M.D. Member
ROBERT ZERBE, M.D. Acting Industry Representative
DORNETTE SPELL-LeSANE, M.H.A., NP-CExecutive Secretary
WOMEN'S HEALTH INITIATIVE PRESENTERS
GARNET ANDERSON, Ph.D.
JANE CAULEY, D.Ph.
ROWAN T. CHLEBOWSKI, M.D., Ph.D.
JACQUES ROSSOUW, M.D.
MARCIA STEFANICK, Ph.D.
WYETH PHARMACEUTICALS TEAM
JOSEPH S. CAMARDO, MD.
CLAUS CHRISTIANSEN, M.D.
J. CHRISTOPHER GALLAGHER, M.D
ROBERT LINDSAY, M.D., Ph.D.
JAMES H. PICKAR, M.D.
FDA REPRESENTATIVES
ERIC COLMAN, M.D.
DAVID ORLOFF, M.D.
BRUCE V. STADEL, M.D., M.P.H.
PUBLIC HEARING SPEAKERS
AMY ALLINA
DAVID ARCHER, M.D.
MARIE FOEGH, M.D., D.Sc.
OMEGA L. SILVA, M.D.
JAMES A. SIMON, M.D.
I-N-D-E-X
Call to Order and Introduction 3
Dr. McClung
Conflict of Interest Statement 6
Ms. Spell-LeSane
Welcome and Introductory Comments 8
Dr. Orloff
Women's Health Initiative Study Results: Implications for the use of hormone therapy with
estrogen/progestin as a second-line drug for the
prevention and treatment of post menopausal
osteoporosis in women.
Open Public Hearing 18
FDA Presentation - Dr. Colman 54
WHI Presentation
Dr. Rossouw 69
Dr. Stefanick 81
Dr. Chlebowski 96
Dr. Anderson 107
Dr. Cauley 128
Dr. Anderson 143
Dr. Rossouw 149
Questions from the Committee 155
Presentation by Wyeth Pharmaceuticals 176
Dr. Camardo
FDA Presentation - Dr. Stadel 246
Charge to the Committee - Dr. Orloff 258
Committee Discussion 260
P-R-O-C-E-E-D-I-N-G-S
8:07
a.m.
CHAIRMAN
McCLUNG: Good morning. I'm Dr. Michael McClung, the acting Chairman
of the Endocrinologic and Metabolic Drugs Advisory Committee. Let me welcome you to today's meeting. We have a very busy agenda that looks like
will be an interesting and enlightening day.
Let
me begin by asking the members of the Advisory Committee and our invited guests
and consultants who are seated around the table to introduce ourselves to both
each other and to the audience. So, sir,
I'm going to have you start with your end with your mouth full. Sorry.
DR.
ZERBE: Sorry. I'm Bob Zerbe, QUATRx Pharmaceuticals and I'm
the Industry representative.
DR.
SCHADE: I'm David Schade, Endocrinology
University of New Mexico, School of Medicine.
DR.
SCHAMBELAN: I'm Morrie Schambelan,
Endocrinology, University of California in San Francisco ("UCSF").
DR.
FOLLMAN: I'm Dean Follman, a
statistician at the National Institutes of Allergy and Infectious Diseases.
DR.
BONE: I'm Henry Bone. I'm an endocrinologist and the Director of
the Michigan Bone and Mineral Clinic. I
guess that's the main thing.
DR.
LUKERT: I'm Barbara Lukert,
Endocrinology, University of Kansas.
DR.
CARPENTER: I'm Thomas Carpenter,
Pediatric Endocrinology, Yale University in New Haven.
DR.
WOOLF: I'm Paul Woolf, Adult
Endocrinologist, Crozer Chester Medical Center.
SECRETARY
SPELL-LeSANE: Dornette Spell-LeSane,
Executive Secretary for the Committee.
MS.
SOLONCHE: And just in time, Martha
Solonche, New York City, the home of the New York Yankees, Patient
Representative.
DR.
STADEL: Bruce Stadel, Medical Officer,
Metabolic and Endocrine Division (FDA).
DR.
COLMAN: Eric Colman, Medical Officer
from Metabolic and Endocrine (FDA).
DR.
ORLOFF: David Orloff, Director, Division
of Metabolic and Endocrine Drug Products (FDA).
CHAIRMAN
McCLUNG: I'm Mike McClung, an
endocrinologist at the University of Oregon Health Sciences Center in the
Oregon Osteoporosis Center. The next
item on the agenda will be to have Ms. Spell-LeSane review the Conflict of
Interest Statements regarding the Committee members.
SECRETARY
SPELL-LeSANE: The following announcement
addresses the issue of conflict of interest with respect to this meeting and is
made a part of the record to preclude even the parents of impropriety at this
meeting. The topics to be discussed
today will not focus on any particular product or company but rather may affect
all companies that make hormone therapies with estrogen-progestin that are
prescribed for the prevention and treatment of postmenopausal osteoporosis.
The
Conflict of Interest statute prohibits special Government employees from
participating in matters that could affect their own or their employers
financial interests. All participants
have been screened for interest in the products and companies that could be
affected by today's discussions.
In
accordance with 18 USC 208(b)(3), the Food and Drug Administration
("FDA") has granted a full waiver to Dr. Henry Bone because the need
for his services outweighs the potential for a conflict of interest. A copy of the waiver statement may be
obtained by submitting a written request to the Freedom of Information Office
HF-135, 5600 Fisher's Lane, Rockville, Maryland 20857.
We
would like to note that Dr. Jacques Rossouw, Dr. Leslie Ford, Dr. Joan McGowan
and Dr. Barbara Alving were involved with the Women's Health Initiative ("WHI") Study as part of their
duties as employees of the National Institutes of Health
("NIH"). We would also like to
note for the record that Dr. Robert Zerbe is participating in this meeting as
the Acting Industry Representative acting on behalf of regulated industry.
In
the even that discussions involve products or firms not on the agenda for which
an FDA participant has a financial interest, the participants are aware of the
need to exclude themselves from such involvement, and their exclusion will be
noted for the record. With respect to
all other participants, we ask in the interest of fairness that they address
any current or previous financial involvement with any firm whose products they
may wish to comment upon. Thank you.
CHAIRMAN
McCLUNG: Questions or comments about
that from the Committee? Let me then
invite Dr. Orloff to make his opening statements to us.
DR.
ORLOFF: Thank you and good morning. I'll read my statement from my seat as is my
usual. Good morning. Thanks to the members of the Committee and
the consultants present for their attendance and to Dr. McClung for agreeing to
chair today's session. Thanks also to
Drs. Stadel and Colman for their important contributions to today's
proceedings.
I
want to recognize in particular Dr. Stadel for a tremendous amount of work in
bringing the FDA and NIH WHI group together for this conference. We are of course very grateful to the WHI
investigators for their willingness to be here today to present the trial
results and to participate in discussion and particularly to Dr. Rossouw whose
close contact with the FDA through Dr. Stadel has made this meeting
possible. Thanks finally to Dornette
Spell-LaSane for here work in managing the complex logistics and legalities and
so on of this important conference.
This
meeting represents the first public FDA meeting and the first joint FDA and NIH
public conference on the landmark Women's Health Initiative Study of Premarin
(medroxyprogesterone acetate, "MPA"), the combination therapy, in
post menopausal women. As everyone
present is well aware, the results of this study have dramatically affected the
thinking as to the role of menopausal hormone therapy in women. The public and individual impacts of at least
combination estrogen-progestin hormone therapy and of estrogen along therapy by
many patients, researchers and practitioners are being reevaluated in light of
the overall balance of risks and benefits in Prempro in this study that was
terminated early having reached stopping criteria based on breast cancer
incidence.
Since
the publication of the primary WHI trial results in July 2002, the FDA always
in collaboration and/or discussion with the NIH has taken several steps. In its role in regulating the marketing of
Prempro in advising physicians and patients on the safe and effective use of
this and other estrogen-progestin ("E + P") combination products and
of estrogen only ("E alone") products, FDA has implemented the
following:
1. Approval of revised product labeling for
Prempro, Premarin as well as for ultimately all U.S. marketed E + P and E along
products, changes that were announced formally in early January of this year. Dr. Colman will take you through these
changes in his presentation.
2. Issuance of revised guidances for industry on
clinical development for post menopausal uses of new estrogen and estrogen plus
progestin products and their labeling.
This is with the particular goal of the development of lowest effective
doses of such products.
3. Provision of information resources on the WHI
and on the safe and effective use of menopausal hormones on the FDA website.
4. Finally, most recently in early September
2003, Dr. McClellan, our Commissioner, launched a nationwide information
campaign partnering with multiple organizations across the United States to
raise awareness on the risks and benefits of menopausal hormone therapy in
light of the results of the WHI Prempro study.
Following
on the results of WHI, the basic recommendations by FDA have been consistent
with those of a number of professional societies and patient advocacy groups,
including the American College of Obstetricians and Gynecologists from which
we'll hear a statement written today and the North American Menopause
Society. Essentially the same
recommendations have been applied to the use of E + P products, obviously those
with the use most directly informed by WHI and in the absence of information
supporting a clear difference in risk versus benefit to E alone products. They are as follows:
1. Estrogen and estrogen plus progestin products
should not be used for primary or secondary prevention of coronary or
cardiovascular disease. Indeed FDA had
never approved labeling recommending such use though it had become a common
rationale among others for what had become known as menopausal hormone
replacement therapy, a term we hold as now clearly inappropriate if not frankly
misleading. Instead alternative
cardio-preventive intervention should be considered.
2. Alternative therapy should be considered for
the relief of menopausal symptoms particularly as a result of vulvovaginal
atrophy as well as for the prevention of post menopausal osteoporosis
("PMO").
3. If estrogens and progestins are prescribed,
they should be used at the lowest doses for the shortest duration to achieve
treatment goals and women should regularly discuss with their healthcare
providers if they need to continue treatment.
Today's
meeting is intended to assess where we, the broad healthcare communities
engaged in areas of patient care, research and drug development, have come thus
far, that is, since July 2002, regarding understanding of and recommendations
for safe and effective use of female menopausal hormone drug products and to
engage in a public discussion of where we ought to be going. The specific objective of this conference is
to discuss the ramifications of the WHI Prempro results for the single chronic
use, prevention directed indication for estrogen-progestin in women. That is preservation of bone mineral content
after menopause.
As
referred to earlier, the revised product labeling for Prempro as well as the
actual or intended labels for E + P and E alone products states that if the use
is solely for the prevention of PMO then alternative approval therapies should
be considered. As such, these products
have essentially been relegated to second line status in PMO prevention based
on risk versus benefit in chronic use.
Any
number of complex clinical and scientific issues remain unanswered by the WHI
study or indeed are raised in its aftermath.
These include but are not restricted to the risk versus benefit of lower
doses of Prempro, the risk versus benefit of other E + P combination products,
the risk versus benefit of Premarin or other estrogen alone products, that is
to say used in the absence of progestin, the risk versus benefit of estrogen
and estrogen plus progestin products administered by alternative routes, for
example, transdermally, and the impact of demographic factors as well as
baseline risk factors, for example, osteoporosis, atherosclerotic
cardiovascular disease, breast cancer, venous thromboembolic disease on the
benefit versus risk of these products.
The
agenda for today's meeting is in your package.
Following the open public hearing, Dr. Eric Colman, the team leader for
Osteoporosis Drugs and Metabolic and Endocrine Division at FDA will provide
background on the historical and current regulatory approach to evaluation of
menopausal hormones and other drug products for osteoporosis prevention and
treatment. A series of presentations
from the WHI group will follow with questions and discussions afterward. After lunch, Wyeth Pharmaceuticals will
present and Dr. Stadel, Medical Officer in Metabolic and Endocrine, will make a
brief presentation based on his review of the WHI findings.
This
is not a typical FDA Advisory Committee meeting. There is no product being considered for FDA
approval today. As such, we have chosen
not to ask at least at the start explicit yes or no questions but rather to
attempt with our questions or with our laying out of issues to direct the
deliberations and discussions on three principal topics. They are and Dr. Colman will review these as well
I suspect:
1. The accuracy, appropriateness and usefulness
of the revised labeling of Prempro after the WHI.
2. The implications of the WHI results for the
clinical development for prevention of PMO of new estrogen plus progestin drug
products, for example, vis a vis endpoints, doses studied, among others.
3. Broadly, further discussion and
recommendations regarding FDA regulation of estrogen plus progestin products
for the prevention and treatment of PMO.
As
you will note, the issues for discussion focus on E + P drug products as
Prempro was the subject of the arm of the WHI that was terminated for safety
reasons. The Premarin alone arm
continues at present as you will hear from Dr. Rossouw and others. While we do not wish to exclude totally any
discussion of the E alone products or of other issues not directly addressed by
the WHI Prempro study, we thought it best at least for the purposes of initial
discussion within the context of the results of this landmark clinical
trial. We fully expect the discussion to
diverge and we welcome it wholeheartedly.
Again, thank you to all for your attendance and we look forward to a
simulating and informative day. I'll
turn it back over to Dr. McClung.
CHAIRMAN
McCLUNG: Thank you, Dr. Orloff. As is the custom for these meetings, input
from the community at large is invited to occur. We will have presentations by six different
speakers during the open public hearing presentation and then a read comment
from one of the major clinical societies.
Other comments are available in information that's on the desk outside
as well. Before inviting the first
speaker though, let me read this comment regarding the Declaration of a
Conflict of Interest from our public hearing speakers.
"Both
the FDA and the public believe in a transparent process for information
gathered in decision making. To ensure
such transparency at the open public hearing session of the Advisory Committee
meeting, the FDA believes that it is important to understand the context of an
individual's presentation. For this
reason, the FDA encourages you, the open public hearing speakers, at the
beginning of your written or oral statement to advise the Committee of any
financial relationship that you have with any company or any group that is
likely to be impacted by the topic of this meeting. For example, the financial information may
include a company's or a group's payment of your travel, lodging or other
expenses in connection with your attendance at this meeting. Likewise, the FDA encourages you at the
beginning of your statement to advise the Committee if you do not have any such
financial relationships. If you choose
not to address this issue of financial relationships at the beginning of your
statement, it will not preclude you from speaking."
With
that stated, let me invite the first of our open public hearing speakers, Dr.
Marie Foegh from Berlex Laboratories.
DR.
FOEGH: Good morning and thank you for
giving me the opportunity to give a short presentation of what I think is
exciting and at least to me surprisingly positive results of a study we have
conducted. Also as you can see from my
first slide, I represent Berlex Laboratories and I'm an employee of Berlex
Laboratories. In my short presentation,
I'll give a short background and then present some of the data from the study,
not all, in the short timeframe, a conclusion and some slides that brings some
source that we have.
I
think most of you are aware of the great importance of preventing bone loss in
post menopausal women. Certain women
beyond 50 years of age have osteopenia or osteoporosis and about 14 million
women have osteoporosis of the hip which results in many women in
fracture. Fracture may sound simple but
it may heal. But we all know in older
women, this may be the beginning of the
end. It's associated with a lot of
disability and in many instances, death will follow.
I
know we all have been used to saying hormone replacement therapy and
replacement in many have been a wrong term, but if it ever were true, it may be true for osteoporosis because
increased bone loss is really a lack of estrogen. What does it result in? You have osteoporosis, osteopenia and you
have apoptosis of the osteocytes and so forth, but this is not a detailed
scientific presentation. This is just
the opening of making the statement that estrogen certainly would be a natural
choice for treating osteoporosis.
We
all know from the WHI study that the risks of using hormones seem bigger than
we original thought. It changed our
thinking like the Chairman also said and the risk/benefit, but we also have to
remember that the dose used in the WHI study may not be the lowest efficacious
dose, but it is the most common used dose today. It's not unreasonably succinct that the risk
may decline the lowering of dose.
What
I'm showing you today will be efficacy of a dose that's 75 percent below a
commonly used dose. This also actually
affects the quality of life. I mean you decrease the estrogen side effects
that is not life-threatening but not pleasant.
It may be feasible to have your cake and eat it.
Berlex
has sponsored a study on osteoporosis in women between the age of 60 to
80. UCSF was the coordinating center and
you'll see some names that are familiar to the osteoporosis field and estrogen
like Dr. Grady, Dr. Cummings and also on the investigator list, there are names
familiar in this field.
This
was a double-blind, randomized trial with 417 women that were as I said between
the ages of 60 to 80 years and they all had an intact uterus. They were more than five years post
menopausal and the entrance criteria was a z-score of more equal to 2.0. The estrogen dose was a weekly transdermal
patch which delivers 0.014 mg of estradiol.
That was tested against a placebo patch.
The
goal was to increase estradiol just to 10-15 picogram per mL. This is a low level of estradiol because you
may all know that women post menopausal have levels below 20 picogram per mL
and nearly all men have actually levels about 20 picogram per mL which may come
to a surprise to many that men have higher estradiol levels than post
menopausal women.
All
the women took calcium and vitamin D of reasonable doses and the study lasted
for two years with follow-ups every four months. The primary endpoint was bone marrow density
("BMD") at lumbar spine. Another primary endpoint was
endometrial safety. There was a series
of secondary endpoints which I will show you some. The hip, of course, are bone markers and so
on.
But
let me focus on the lumbar spine. The
blue represents the placebo group and the red represents the active arm, the
estradiol group. You have the data at 12
and 24 months. As you can see, there's a
2.5 percent difference between placebo and the active arm at 24 months, a
highly significant result of a P-value less than 0.001. This is very comparable to other estrogen and
other compounds that SERMs use for treatment of prevention of osteoporosis.
To
the hip, the results were also highly statistically significantly different
both at 12 and 24 months. Again the blue
is the placebo and there is as you can see an increasing bone loss and that is
counteracted by the estrogen and again a highly significant difference of 1.5
percent at 24 months.
We
also had a secondary endpoint of fractures.
Of course we were aware that the study wasn't big enough to show any
difference in fractures, but as you can see numerically at least there is a
difference. There is four in the active
arm and 10 fractures in the placebo arm.
These are women with fractures.
Some of those women had several fractures, but this is women with
fractures at any given time.
In
August, most of you are aware that a study was published on what I would also
call an ultra-low dose of estradiol.
That was Dr. Prestwood and her collaborators. And Dr. Cummings, one of the investigators,
pooled the data of these two ultra-low studies and the combined factors were
that there were six fractures for the ultra-low and sixteen for placebo. This is statistically significantly different of a p-value of 0.4. This is really exciting because these are
mainly osteopenic women and these are fractures that we are talking about. So it's very encouraging.
What
were the adverse events? Here's adverse
events we worry about namely, breast cancer, cardiovascular events. These are what they look like in this study
which lasted for two years. We looked at
all but what I've summarized here for you are the breast cancer and the
cardiovascular. It was interesting when
you glance over it. There is really no
difference between the placebo and the active arm.
One
interesting point is actually that we did not have any venous thromboembolic
events. If you go down to the
bottomline, I thought it might be interesting also to see there were no deaths
in this age group and the hospitalization was not statistically significantly
different. It was 22 in one group and
ten in the other.
This
is the conclusion. You will notice that
you haven't seen all the data. This is
because I got my talk cut short yesterday.
But of course I am willing to give the data if you ask. What we found is the prevention of bone loss
in all the post menopausal women with this dose that is 75 percent lower than
the normally used dose. It is safe for
the endometrium. The study lasted for
two years so for two years you do not need to use progestin. There was decrease in the bone markers and
there was no difference in some of the normal estrogen related side effects
like breast tenderness, headache. If you
look at the bottom, there was also no difference in lipids, sex hormone binding
globin ("SHBG") or C-reactive protein ("CR-P") between the
two groups.
So
we really think that this effect of this ultra-low dose is kind of a paradigm
shift in the risk-benefit of the hormone use.
We showed that it seems that you would be able to get a fracture
reduction in osteopenic patients. You
can give anapost estrogen at this dose for up to two years. We do not know what happens after two
years. The adverse event profile is
similar to placebo. We have no increase
in the vasomotor symptoms. We don't
share of course bisphosphonates effects because we are transdermal
products. Thank you so much for your
attention.
CHAIRMAN
McCLUNG: Thank you. Are there questions or comments? If not, thank you very much. The second presenter will be Susan Wysocki
who is the President and CEO of National Association of Nurse Practitioners in
Women's Health. If she's not here, we'll
come back to that point in a moment.
Next, let me invite Dr. David Archer, who will speak on behalf of the
American Society for Reproductive Medicine ("ASRM"). Dr. Archer.
DR.
ARCHER: Thank you very much, Dr.
McClung. Good morning, ladies and
gentlemen. It's a pleasure to be with
you this morning in Washington although it's a little brisk outside. I represent the American Society for
Reproductive Medicine and myself at this meeting.
Both
AMRM is composed of physicians and I am a physician. As such, we've been involved in medical
education and clinical trials for many years.
Because of this, both of us have received grants, funds, clinical
research dollars from I would say every pharmaceutical company in the United
States that makes a hormone preparation for menopausal women. That is my disclaimer in terms of our
conflict of interest. I am expecting
that ASRM will reimburse me for my expenses so I am not here as representing a
pharmaceutical company.
Currently
I am a professor of obstetrics and gynecology at the Eastern Virginia Medical
School. I'm an obstetrician/gynecologist
with advanced certification in reproduction endocrinology. The ASRM is really pleased to be a partner
with the FDA in terms of its campaign for educating women as they consider
hormone therapy for post menopausal symptoms.
However, we all are concerned with the fact that media publicity has
resulted in symptomatic women who could benefit from hormone replacement
therapy by using approved and appropriate therapy for the relief of symptoms.
We
know that hormone therapy improves symptoms and the quality of life for these
women. I think we're all concerned that
the media has characterized hormone therapy as harmful to women, particularly
in cardiovascular disease and breast cancer.
I believe the scientific community and physicians realize that the
relative risk numbers are often high, but the attributable risks in the
community is a different issue.
Young
women between the ages of 45 to 55 who are peri or post menopausal and are
symptomatic are a different class of women than those reported in the WHI. These younger women are good health. They are not at apparently increased risk of
cardiovascular disease with the use of hormone therapy. The current final report from the WHI in July
of this year really did not find overall an increase in coronary heart disease
in women receiving hormone therapy. We
do acknowledge that there was an increase in coronary heart disease in the
first year of use but again point out that the average age of women in this
study was 63, significantly older than the 50 year old woman that we frequently
see in our practices.
As
some example for this risk, if you log on to the American Heart Association
website, www.americanheart.org and use the Framingham
risk factor for the identification of heart disease risk in a 55 year old woman
who has a mild elevation in her total cholesterol level, her actual
attributable risk are her risks of developing heart disease in the next ten
years is less than one percent. So we
would submit that there is very low risk for these women who are younger and in
good health of developing significant adverse events particularly those related
to the cardiovascular system.
We
feel that this underscores the fact that consumers really apply the results of
what's published in the media to themselves inappropriately. Anecdotally as I've said to other people,
I've had a 47 year old woman consider hormone therapy be concerned over the
fact that she might develop Alzheimer's disease in the next several years. So that all of us take the sound byte from
the media and apply it to our particular lifestyle.
Now
we all know that breast cancer is a significant issue for women. However in the WHI, women who had never used
hormone therapy and entered this trial
and were randomized were not found to have a significant increase in the
occurrence of breast cancer during the five years of the clinical trial. Only in those women who had previously used
hormone therapy was there an apparent increase in the incidence of breast
cancer.
So
the average age of the woman 50 to 55 who is symptomatic and requests treatment
is really not at a particularly increased incidence of breast cancer from the
use of hormone therapy using the relative hazard published in the WHI. I might also point out that the most
important risk factor for breast cancer from numerous publications is that of
age itself.
Now
as I pointed out in this anecdotal case which as I realize is inappropriate in
front of an August body such as this dealing in large numbers that the issue of
cognition in Alzheimer's disease really need to be clarified for the
consumer. The WHI memory study showed an
increase in the occurrence of cognitive decline in Alzheimer's or probable
Alzheimer's disease after approximately two years of hormone therapy. However it should be pointed out which is not
pointed out for many of the consumers that this study occurred in women who
were over the age of 65. So the
relevance of this finding to younger women is at present unknown.
I'm
not cognitively impaired. I just need my
helper right here in front of me. So
it's obvious for the younger symptomatic woman who is complaining of hot
flashes, night sweats, difficulty sleeping, mood fluctuations and vulvo-vaginal
atrophy that the message that we should deliver as physicians to this group of
patients is that hormone therapy can relieve these symptoms without resulting
in significant mortality or morbidity in terms of its outcome.
I
believe that this message is important for women who may or may not have risk
factors for bone loss. Current data from
the WHI and other publications indicate that standard and lower doses of
estrogen with progestin or estrogen alone prevent bone loss in post menopausal
women. This is based on the findings
with DXA scanning and this group of individuals are duel-energy X-ray
absorptiometry.
The
WHI recent publication allows us to I think unequivocally conclude that
estrogen plus progestin reduces the incidence of fracture of the hip, spine or
vertebral body and wrist in all the subgroups of post menopausal women. We believe that these data provide a
compelling reason to initiate hormone therapy for the prevention of bone loss
and fractures in post menopausal women.
The position of the ASRM therefore is supportive of the use of hormone
therapy in post menopausal women with the understanding that this use is based
on the patient's unique risk/benefit profile.
I want to thank you very much for allowing me to make this presentation
this morning.
CHAIRMAN
McCLUNG: Thank you, Dr. Archer. Comments or questions? Thank you very much. Our next speaker is Dr. Omega Silva, the past
President of the American Medical Women's Association ("AMWA").
DR.
SILVA: I am Dr. Omega Silva,
Endocrinologist and Past President of the American Medical Women's
Association. I appreciate the
opportunity to present AMWA's views on the implications of the WHI for the use
of hormone therapy with estrogen and progestin as a second line drug in the
prevention and treatment of post menopausal osteoporosis in women.
Founded
in 1915, AMWA is an organization of 10,000 women physicians and medical
students dedicated to serving as the unique voice for women's health and the
advancement of women in medicine. AMWA
supports the current FDA approved indications for hormone therapy. Hormone therapy is the most effective FDA
approved treatment for menopausal symptoms such as hot flashes, night sweats
and vulva and vaginal atrophy. Hormone
therapy is also indicated for the prevention of post menopausal
osteoporosis. AMWA is proud to be a
partner in FDA's menopause and hormones information campaign which provides
women with important information about hormone therapy.
As
physicians, our role is to review a patient's family and medical history and
assess the risks and benefits of hormone therapy for that individual. We can help our patients by putting the risks
into proper perspective. While hormone
therapy may not be appropriate for one woman, it may be entirely appropriate
for another.
With
regard to osteoporosis, AMWA recognizes the enormous impact of the disease on
the health of Americans, particularly women.
The disease causes over 1.5 million fractures yearly at a cost of $17
billion. Following osteoporoic hip
fracture, there is an excess mortality of 12 to 20 percent. Hip fracture is the second leading cause of
admission to nursing homes for women.
Osteoporosis
causes severe and unrelenting bone pain.
It is one of the major debilitating disorders that contribute to the
loss of functional independence and quality of life in older women as noted in
AMWA's position paper on osteoporosis.
To
prevent osteoporosis, AMWA members recommend weight-bearing exercise, adequate
calcium and vitamin D intake and the maintenance of a healthy life style. In addition, medications to prevent further
bone loss may be indicated. Women who
think they are at risk of developing osteoporosis should consult their
physicians. Treatment plans should be
initiated as early as possible because once bone is lost it's difficult to
replace as noted in AMWA's osteoporosis question and answer fact sheet.
The
recent study in the October 1, 2003 issue of the Journal of the American
Medical Association ("JAMA") demonstrated that estrogen plus
progestin increased bone mineral density and reduces the risk of all fractures
in healthy post menopausal women. This
decreased risk of fracture appears to be present in all subgroups of women
examined. When considering effects of
hormone therapy on other important disease outcomes in a global index developed
by the WHI investigators, the study authors concluded that there was net
benefit of hormone therapy even in women considered to be at high risk of
fracture.
On
this point, AMWA notes that the global index is based on selected risks and
selected benefits and not on all risks and all benefits. For example, it includes hip fractures but
not for tibial fractures or menopausal symptoms, the primary reason women take
hormone therapy. For some women, the
risk/benefit equation might change when relief from post menopausal symptoms
and prevention of tibial fractures are taken into account.
AMWA
agrees with the current FDA approved labeling for hormone therapy, Prempro,
which states that when prescribing solely for the prevention of post menopausal
osteoporosis therapy should be considered for women at significant risk of
osteoporosis and non-estrogen medications should be carefully considered. If hormone therapy is prescribed, it should
be taken at the lowest possible dose for the shortest duration of time to meet
treatment goals.
The
WHI results have reinforced what physicians have known all along. Treatment decisions should be
individualized. For this reason, it is
extremely important for FDA to preserve physician and patient choice of
therapeutic agents to prevent and treat osteoporosis. Hormone therapy remains an important option
for those women at risk of osteoporosis who are unable to take non-estrogen
medications.
On
behalf of AMWA, I thank you for the opportunity to testify before the
Committee. I have no problems with
getting money from this person or that person because nobody gives me any. Now I would like to become a patient. How much time do I have? A few minutes.
Now
I would like to become a patient and give you a personal scenario. I'm 66 years old and follow the textbook
version of peri-menopause and menopause and post menopausal symptoms, getting
those first little nasty hot flashes at age 45, becoming a post menopausal
woman at 50.5. When I was 45, the data
on the benefits and risks were very sparse, but became better when I was about
52 or 53. So I began HRT and continued
until May 30, 2003. At that point I said
after the WHI results, "Well, maybe I can do without this HRT now." Within a week, those nasty little hot flashes
returned. My husband said "For
crying out loud, you're hot one minute and cold the next." Sleeping was a ritual of getting up and
turning my pillow over on the cool side.
Now
I was going on an Alaskan cruise in September.
So I said "I'll be damned if I'm going to sweat and hot flash
myself through this cruise." There
was no breast cancer in my family. My
aunts on my mother's side lived to be 90 plus.
One just died of pneumonia at age 100.
My mother did die of cerebral hemorrhage but she had no thromboembolic
events. My father at age 94 just had
colon cancer. Therefore, I weighed by
personal risks and benefits and restarted my HRT and enjoyed my cruise and life
thereafter. Many of you men may not
understand and I wouldn't wish prostate cancer on any of you but if you do get
it and you have to take those anti-testosterone therapies, you may feel some of
these hot flashes and then you'll know what the women go through. Thank you.
CHAIRMAN
McCLUNG: Thank you, Dr. Silva. Questions or comments? Great.
Thank you. Next let me invite Dr.
Jim Simon who is the current President of the North American Menopause Society
to deliver his remarks. Dr. Simon.
DR.
SIMON: Dr. McClung, members and guests
of the Committee, I would like to suggest that perhaps everyone can go home
early today since today's Washington Post seems to have published a
short article saying "The whole issue has already been settled." Page F-2 in today's Washington Post,
it's interesting reading.
Today
I need to give the following personal introduction. I'm a clinical professional of obstetrics and
gynecology at George Washington University here in Washington. I am also President and CEO of a independent
investigative research site that works with literally the entire pharmaceutical
industry since its inception. So I
potentially have conflicts as mentioned by Dr. Archer. However today and uncharacteristically of me
as a person for those of you who know me which most of the people do, I'm going
to stick closely to the script provided to me by my colleagues at the North
American Menopause Society and will be uncharacteristically short and
non-controversial.
I
would like to focus attention on the estrogen and progestin use in peri
menopausal and post menopausal women position statement published by the North
American Menopause Society on September 17, 2003. All the Committee members have a copy. This position statement represents a
significant amount of work by a smattering of true experts on this subject from
around the world including five individuals who are WHI investigators. Many of them also HERS ("Hysterectomy
Educational Resources and Services") and WHIMS ("Women's Health
Initiative Memory Study") investigators, and including Dr. Stefanick who
is a member of this Committee. The
information is available to you in this publication. For those who don't have a copy, on the web
at www.menopause.org. It is an update of
a former position statement from last year.
I
want to focus attention only on a couple of major points and leave it to the
Committee to use this learned piece of work some 14 pages with appropriate
references for their own purposes. Under
areas for which there was consensus on the Committee, there is definitive
evidence for estrogen-progestin therapies efficacy in reducing the risk of post
menopausal osteoporoic fracture. There
is today no comparable evidence for estrogen therapy. Many estrogen-progestin therapies and
estrogen therapy products are Government, that is FDA, approved for prevention
of post menopausal osteoporosis through all term treatment.
Because
of the potential risk associated with hormone therapy for women who require a
drug therapy for osteoporosis risk reduction including women at high risk of
fracture within the next five to ten years, alternatives to hormone therapy
should also be considered weighing the risks and benefits of each. Recognition should be given to the fact that
there are no published data on osteoporosis drug therapies beyond seven years.
The
effects of hormone therapy on the risk of breast cancer and osteoporoic
fracture in symptomatic peri-menopausal women have not been established in
randomized clinical trials ("RCT").
The findings from trials in different populations, for example, the WHI,
should therefore be extrapolated with caution.
There is however no evidence that symptomatic women differ from
asymptomatic women in either cancer or bone outcomes.
Premature
menopause and premature ovarian failure are conditions associated with earlier
onset of osteoporosis and cardiovascular disease, but there's no clear data as
to whether estrogen therapy or estrogen-progestin therapy will reduce morbidity
or mortality from these conditions. The
benefits/risks ratio may be more favorable for younger women.
There
were also some areas where there were no consensus that could be reached by
this Committee. However there were no
areas of non-consensus vis a vis osteoporosis.
I would say with my personal hat on and not my North American Menopause
Society hat on and they are paying for my parking today that I would ask the
Committee in their deliberations to try very hard not to further limit access
to therapies this and any other so that we working in the trenches may exercise
clinical judgment in the care of our patients one patient at a time. Thank you.
CHAIRMAN
McCLUNG: Thank you, Dr. Simon. Questions or comments? Let me invite then Amy Allina who is the
Program Director for the National Women's Health Network who will be our next
speaker.
MS.
ALLINA: Thank you. I am Amy Allina, the Program Director of the
National Women's Health Network ("Network"). The Network is a non-profit organization that
works to improve the health of all women by developing and promoting a critical
analysis of health issues to influence public policy and to support consumer
decision making. We accept no financial
support from pharmaceutical or medical device companies. We're supported by a national membership of
about 8,000 individuals and 300 organizations.
As
many of you here today are aware the Network has a long history of advocacy and
consumer education on the issue of hormone therapy for women at menopause. We've spoken at numerous FDA Advisory
Committee meetings on the topic over the last 15 years. We were leading advocates calling on the NIH
to conduct the WHI so that women would have well founded scientific research to
guide their decision making about the use of hormone therapy. We've produced extensive health education
materials for women who are considering this therapy and we are also a partner with
the FDA in the patient education campaign that was recently announced by Dr.
McClellan.
Though
we understand the perspective of the many researchers and clinicians and even
some women who were disappointed with the findings of the WHI. We are really pleased that there's finally
data from a large long-term RCT of hormone therapy for healthy women. Hormone therapy has been prescribed to women
for decades without this data to back it up.
Though the WHI results leaves some women with new questions about what's
best for their health, we believe it's better to know what these questions are
than to make healthcare decisions based on unproven and false assumptions. We're also pleased to be able to speak here
today and thank the FDA for the opportunity to give input on the implications
of the WHI results for FDA regulation of estrogen plus progestin drug products,
specifically regarding long-term use of the products for prevention and
treatment of PMO.
We'd
like to start by commending the Agency for acting quickly to work with sponsors
on a revision of the prescribing information that accompanies Prempro and other
estrogen plus progestin products that are approved for prevention of
osteoporosis and for identifying it as a second line option for this
purpose. Although the WHI results that
were released were based only on the study of women using Prempro, FDA acted
based on its recognition that other estrogen and estrogen plus progestin
products work in similar ways and asked for revisions on other product
labels. We agree and we believe it's
important for women using those products to have information about the benefits
and risks identified by the WHI.
In
thinking about the implications of the WHI results for future regulatory
decisions, there are a lot of important questions about study design that the
Agency is going to have to grapple with and that all of you will have to
grapple with. In considering the conduct
of trials or approval of an estrogen plus progestin drug product for the
prevention and treatment of PMO, how many women need to be studied? How long do they have to be studied? Are there surrogate safety endpoints that the
Agency can accept?
Historically
approval's been based on studies of three year duration or in some cases with
less, but we know that the risks of Prempro didn't emerge within that
timeframe, at least with respect to breast cancer. Given the knowledge we know have about the
serious health risks with estrogen plus progestin products that emerged after
six years, we believe FDA cannot approve similar drugs for long-term use
without requiring that they studied for that length of time. An interim exception might be made for
products containing only estrogen since the arm of WHI studying estrogen alone
is on-going. Until those data are
collected and analyzed, it's not known whether all the same risks will apply to
those drug products.
Regarding
surrogate endpoints, the WHI has shown that the surrogates that have been used
in the past for cardiovascular disease were not predictive. Given what's now known about the increased
risk of cardiovascular disease associated with long-term use of estrogen plus
progestin drug products, surrogate safety points really aren't acceptable.
Finally,
I wanted to address some of the points that were brought up in materials that
Wyeth Pharmaceuticals prepared for today's meeting and that we've heard echoed
in messages from a couple of other groups speaking today regarding the factors
that they believe limit the interpretation or generalize ability of the WHI
results. Wyeth wrote that the WHI
recruited women of relatively old age in comparison to the onset of menopause
and therefore that the risks associated with hormone therapy can be expected to
be substantially lower than those observed in the WHI. We just wanted to emphasize - I'm sure that
this point will be brought up by the presentation from the WHI - that a third
of the women in the study, the total of 5,702, were in their 50s. This is the largest RCT ever done of women in
this age group.
The
company also wrote that because the WHI excluded women with severe menopausal
symptoms, it was examining a population that was not representative of the
women for whom the product is principally indicated. In fact at the start of the trial, 12 percent
of the women enrolled reported experiencing moderate to severe hot flashes or
night sweats and more over, research conducted among women who were taking
hormones prior to the release of the WHI result has shown that only a minority
said they said taking hormones because of hot flashes.
The
company also suggested that the study population wasn't representative of women
for whom the product is indicated because it included a number of participants
who were overweight, past or current smokers and being treated for high
cholesterol, high blood pressure and
diabetes. These conditions are common in
the general population and like most people who enroll in clinical trials
designed to study disease prevention, the women in the WHI were probably
healthier than the general population due to the healthy volunteer effect. This supposition is supported by the fact
that the rates of cardiovascular disease while increased in the treatment arm
were lower in both the estrogen plus progestin group and the placebo group than
they are in the general population.
So
in conclusion, I just want to thank the FDA again for acting promptly and
responsibly when the WHI results were released and to encourage a similar
approach as the Agency moves forward to consider future research and product
approvals. While it is important to be
clear and specific about the regimen that was studied in the WHI and the
regimens for which we will have data in the future, it's also important to
build on the knowledge that the trial has given us and to act based on
that. Thank you.
CHAIRMAN McCLUNG: Thank you for your comments. Let me invite again Ms. Susan Wysocki if
she's in the audience. If not, let me
proceed and ask Ms. Spell-LeSane if she will read into the record the comment
from the American College of Obstetrics and Gynecology.
SECRETARY
SPELL-LeSANE: Statement of the American
College of Obstetrics and Gynecology ("ACOG") on Hormone Therapy for
the Prevention and Treatment of Post Menopausal Osteoporosis for the FDA
Endocrinologic and Metabolic Drugs Advisory Committee. The ACOG representing over 45,000 healthcare
professionals dedicated to women's health is pleased to offer this statement to
the U.S. Food and Drug Administration Endocrinologic and Metabolic Drugs
Advisory Committee on the use of hormone therapy for the prevention and
treatment of PMO in women.
Last
week Cauley, et al., published an updated final analysis of fracture endpoints
in WHI RCT. They found that use of conjugated equine estrogen
("CEE") 0.625 mg per day and MPA 2.5 mg per day reduced the risk of
hip fracture by 33 percent, hazard ratio 0.67, nominal 95 percent confidence
interval 0.47 to 0.96. Subgroup analysis
showed that use of estrogen plus progestin resulted in a statistically
significant reduced risk of hip fracture in women who had experienced menopause
at least 20 years previously, who had a body mass index ("BMI") of
less than 25, who had at least two falls in the past year, who reported a daily
calcium intake of at least 12,000 mg per day,
who had no history of fracture, who had used hormone therapy for either
less than five or at least ten years.
Similarly hormone therapy also reduced the risk of total fractures by 24
percent, hazard ratio 0.76, confidence interval 0.69 to 0.83.
Benefits
were seen in bone mineral density ("BMD") as well. The change in BMD from baseline was higher in
hormone users in both hip and spine and at every interval of follow-up
reported. After three years, the
percentage difference was 4.5 percent for lumbar spine and 3.6 percent for
total hip. This final analysis confirms
that previously reported data from the WHI which demonstrates that estrogen
plus progestin is protective against both fractures and loss of BMD. It is concordant as well with a wealth of
other RCT and observational studies.
The
evidence is strong and consistent. Use
of CEE and MPA helps prevent osteoporosis by slowing bone loss and is valuable
in treating this condition as well. The
WHI report however calculate a global index to quantify overall benefit versus
risk of estrogen-progestin therapy.
Because Cauley, et al., calculated the global index hazard ratio to
range from 1.23 to 1.03 depending on a woman's risk of fracture, they concluded
that there was no evidence of a net benefit and recommended that treatment with
estrogen plus progestin not be used for prevention and treatment of
osteoporosis in women without vasomotor symptoms.
We
cannot agree with this global index approach because we believe it is to be
biased. In our analysis of original WHI
data on BMD and fractures, ACOG offered the following guidance:
"1. The decision about use of hormone therapy
requires evaluation of the risks and benefits for each individual woman.
2. For women currently using hormone therapy, it
is important to assess their reasons for using and to evaluate potential risks,
benefits and alternatives.
3. For patients with osteoporosis, other
preventive therapies such as bisphosphonates and selective estrogen receptor
modulators are available.
4. For women at risk of osteoporosis who have
vasomotor symptoms, hormone therapy can be of benefit.
5. Periodic reassessment of the need for hormone
therapy is recommended at least at every annual visit or more frequently if
indicated."
We
continue to support the judicious individualized use of estrogen and progestin
for bone protection and believe that it is inappropriate to withhold this
treatment option from those who need it and would benefit from it. While we noted that there are other agents
approved for prevention and treatment of osteoporosis, each of these agents has
its own contrary indications and side effects.
Some actually increase hot flashes and they would not be a choice of
women with vasomotor symptoms.
In
offering the global index hazard ratio, the WHI investigators attempted to
estimate overall benefit versus risk.
Although this concept is potentially useful from a public policy
perspective, it falls short as guidance for care of individual patients. Ultimately this weighing of benefits and
risks must be done by each individual physician with each individual patient.
ACOG
continues to educate its fellows and their patients on the current
understanding of benefits and risks of hormone therapy and participated with
the FDA in its recently launched menopausal hormone therapy educational
campaign. We look forward for continuing
to work with the FDA on this issue.
Isaac Schiff, M.D., Chair, ACOG Task Force on Hormone Therapy, Stanley
Zinberg, M.D., Vice President, Practice Activities.
CHAIRMAN
McCLUNG: Thank you. And I would like to thank all of the speakers
for their comments and critique this morning to help set the stage for our
subsequent discussion. I'm going to turn
and invite Dr. Eric Colman who is the Team Leader for the Osteoporosis Drugs of
the Division of the Endocrinologic and Metabolic Drugs of the FDA to review the
criteria for the effectiveness and safety in the evaluation of osteoporosis
drug products and specifically as it applies to the estrogen-containing compounds. Dr. Colman.
DR.
COLMAN: Thank you, Mr. McClung. What I wanted to start with is just an
outline of what I'll be talking about for the next 15 minutes or so beginning
with some terminology that I'll be showing you and then move into a brief
regulatory history of the estrogens and the estrogen plus progestin and then
show you the actual products that are currently approved for the prevention of
PMO. Finally, I show you some parts of
the labeling that have been changed in response to the Prempro arm of WHI.
You
will see that estrogen is denoted as "E" and progestin
"P". Estrogen plus progestin
is "E + P". Conjugated equine
estrogens is frequently abbreviated "CEE". Medroxyprogesterone acetate is
"MPA". Those two compounds
together comprise Prempro and Premphase.
The standard post menopausal osteoporosis "PMO". Bone mineral density "BMD". And randomized control trials
"RCT".
The
regulatory history of estrogens dates back to 1942. This was when the Agency approved CEE or
Premarin for menopausal symptoms. It was
then roughly 30 years later when the labeling for estrogen said they were
probably effective for selective cases of osteoporosis. This was a designation that came by way of a
process called "DESI" which stands for Drug Efficacy Study
Implementation. The National Academy of
Sciences was contracted and they put together some experts. They looked at the available literature on
estrogens and bone. The best they could
come up with was a phrase saying "Estrogens are probably effective for
select cases of osteoporosis."
That's the way that stood for years.
In
1986, that was updated to read "Estrogens are effective therapy for
osteoporosis." Throughout the
1990s, the labeling for these products used the words "management and
prevention". There was a certain
amount of confusion over what the word "management" meant to a lot of
people. So we thought the best way to
handle that was to take it out. Most
recently, we have taken out the word "management" and the labeling
now simply reads "prevention of osteoporosis". I'd also mention that all of these labeling
claims are based on data related to bone density and not to fracture data.
Prempro
CEE/MPA was approved for the prevention of osteoporosis in 1994. It was a somewhat of an usual approval in
that Premarin CEE was already approved for the prevention of PMO, the same dose
0.625. The reasoning was we have the
same dose of estrogen. We're adding a
progestin. At that time, some people
felt that there was evidence that progestins had their own independent positive
effect on bone density. The feeling was
if we have a progestin that has a positive effect on bone, maybe we can lower
the dose of estrogen, avoid some of the known estrogen adverse effects but
still end up with a positive overall effect on bone density.
Prempro
was approved in 1994 for osteoporosis.
At the same time, Wyeth agreed to do a post approval study looking at
lower doses of Prempro and Premarin with BMD as the primary outcome. That study has been published. It's referred to as the "HOPE"
trial. In fact, the data from that trial
are the basis of the recent approval of lower doses of Prempro and Premarin,
doses lower than what was used in WHI.
Again those are BMD data. I will
mention that again in a second.
The
other thing that happened in 1994 was the Agency updated its osteoporosis
guidance. The guidance had separated out
estrogens from non-estrogens. As far as
the estrogens were concerned, there was a statement there that said "The
epidemiologic data are sufficient to conclude that estrogens reduce the risk
for osteoporoic fracture." That's
somewhat unusual in that the Agency took a position that epidemiologic data
were sufficient to conclude a fracture benefit of estrogens. That's what was in the guidance.
Subsequently
no company other than one tried to get a treatment indication which would mean
a fracture indication for an estrogen or E + P.
From that day on, we have been dealing primarily with prevention of PMO
for estrogens. For a company to get a
prevention of PMO indication, they had to do a two year trial with lumbar spine
BMD as a primary endpoint and they had to compare their drug again to placebo
and show that their drug led to a statistically significant increase over
placebo.
Just
briefly to recap, the E and E + P products approved for the prevention of PMO,
the approval came about in general through one of two mechanisms. The older products were just designated as a
DESI drug or the company had to do a two-year randomized placebo controlled
trial with lumbar spine as a primary endpoint.
In general, the women in these trials had normal or osteopenic bone
density at baseline. By and large, the
trial sizes were less than 500 women.
I'd
like to show you this just as a point of reference. This outlines the
requirements for approval of the non-estrogens.
This would be, for example, alendronate (Fosamax, Actinal (risedronate)
and in fact, even SERM raloxifene. Here
you will see where treatment becomes synonymous with fracture reduction and
prevention, synonymous with BMD. For a
non-estrogen to gain a treatment indication, the company had to do a three year
RCT demonstrating that their drug significantly reduced the risk of vertebral
fracture relative to placebo.
Once
that was done and the company wanted a prevention of PMO indication like with estrogens, they had to do a two year
trial looking at lumbar spine BMD. That
was the same as it was with the estrogens.
On top of that, they had to have a large favorable preclinical profile
for the drug and the clinical development program for these compounds in the
last eight years have been quite large, anywhere from 5,000 to 15,000 trial
subjects.
As
of today, there are several E + P products approved for the prevention of PMO
again based on BMD. There are no E + P
products approved for the treatment of PMO, again treatment synonymous with
fracture efficacy which I basically said at the bottom of this slide.
The
next two slides I want to show you the actual E and E + P products that are
approved for PMO. This slide shows you
Prempro and Premarin. You will notice
that I have shown four doses in yellow.
You recall that the 0.625 to 2.5 dose of Prempro was what was used in
WHI. Fairly recently, the Agency has
approved the lower doses of 0.45, 0.3, and 1.5 Prempro for the prevention of
PMO. Again those come from BMD data from
the study that Wyeth agreed to do back in 1994.
So it's referred to as the HOPE trial.
The
lower doses of Premarin were also studied in that trial. Again those data form the basis for the
recent approval of two lower doses of Premarin.
They are all based on BMD.
This
slide shows you the other products that are approved. You will notice that there are different
estrogen compounds here. There are two
different progestin compounds. There are
several different doses. You will also
notice at the bottom there are two patches to transdermal preparations. So there are a host of different E and E + P
products currently available, all limited to BMD data in fairly small trials,
but they do offer some difference in the composition of the estrogen and the
progestin, the doses and the delivery system through two transdermal.
To
summarize, there are several E + P products in addition to Prempro that are
approved for the prevention of PMO.
There are no E + P products approved for the treatment, treatment again
synonymous with fracture reduction. This
is somewhat ironic. WHI now provides
strong evidence that E + P reduces the risk for osteoporoic fracture including
the hip.
My
last bullet is taken verbatim from last week's WHI Fracture paper that was
published in JAMA where the authors concluded that there was "...no
net benefit, even in women considered to be at high risk of
fracture." Of course if you look at
the global index, the women who had the highest baseline risk, their global
index was getting pretty close to one.
The global index does not include vertebral fractures so those
components obviously will lead to I would think some discussions about "Is
there possibility a subgroup who might benefit particularly with lower
doses" but that's more hypothetical.
Let
me move on the labeling changes at this point.
I want to show you all the labeling changes. The labeling changes that I'll show you I've
highlighted three sections, but the changes that have been made to Prempro and
Premarin. All manufacturers of E and E +
P had been requested to make the same changes.
I don't know where we stand in terms of getting the responses back but
letters have been sent to those individuals saying "You need to make these
changes as well even though you're a transdermal, even though you're a
different preparation."
Let's
go to the black box warning. This is a
little tedious because I've copied a lot here.
The black box warning is the first portion of the label on the Prempro
label. The first thing it says is
"Estrogens and progestins should not be used for the prevention of
cardiovascular disease. The Women's
Health Initiative study reported increased risk of myocardial infarction,
stroke, invasive breast cancer, pulmonary emboli and deep vein thrombosis in
post menopausal women during five years of treatment with CEE combined with
MPA."
This
gets to the other doses and other products.
"Other doses of conjugated estrogens and medroxyprogesterone
acetate and other combinations of estrogens and progestins were not studied in
the WHI. In the absence of comparable
data, these risks should be assumed to be similar." That is the approach that the Agency has
taken thus far. If you don't have data
to prove you're different, you're going to be assumed to be the same.
"Because
of these risks, estrogens with or without progestin should be prescribed at the
lowest effective dose and for the shortest duration consistent with treatment
goals and risks for the individual woman."
It sounds very logical.
Now
the indications and usage section, the first two indications, the first has to
do with vasomotor symptoms. The second
has to do with vulvovaginal atrophy.
Those are two of the three continuing indications for this product. The third indication is a prevention of PMO
which now reads "When prescribing solely for the prevention of post
menopausal osteoporosis, therapy only should be considered for women at
significant risk of osteoporosis and non-estrogen medications should be
carefully considered." This is
suggesting that this should be a second line agent or you should have real good
reason to use this over other products already out there.
Finally,
the dosage and administration, some more wording that we've seen before. "Use of estrogens alone in combination
with progestin should be limited to the shortest duration consistent with
treatment goals and risks. Patients
should be reevaluated periodically as clinically necessary." The top portion here is more about the
osteoporosis. At the bottom, it says
"Patients should be treated with the lowest effective dose. Generally women should be started at 0.3, 1.5
Prempro." Again this is a recently
approved dose. "Dosage may be adjusted
depending on the individual, clinical and bone mineral density responses. This dose should be periodically reassessed
by the healthcare provider."
That
concludes the basis of my presentation.
I just want to leave you with some issues we hope will be the focus of
today's Committee discussion. Some of
these issues Dr. Orloff mentioned earlier.
I just want to reiterate those.
At the end of the day when all is said and done, we're going to ask the
Committee to comment on the revisions made thus far to the Prempro labeling
keeping in mind that these changes have been made to the whole class of E and E
+ P. It's not simply Prempro. We also will ask you to discuss the
implications of the WHI trial results for the future development, testing and
potential approval of E + P drug products for the prevention and/or treatment
of PMO.
Again
I told you that currently it takes two years of BMD data to get prevention
indication. You can do that with well
under 500 women. We now have fairly good
fracture data from WHI which if the balances were a little bit more favorable
then it's possible that this Prempro would have a treatment indication now
because we do have good fracture data now.
There are some things to think about.
How big a trial should people undertake?
What should the endpoints be?
Should they require to show fracture?
Finally
it's just a very open-ended question for you to provide other comments or
recommendations related to the WHI trial or to regulation of E + P products for
the prevention and/or treatment of PMO. Thank you.
CHAIRMAN
McCLUNG: Thank you, Dr. Colman. We'll have our discussion about that during
the discussion section but let me invite the Committee members if there are
specific questions to address to Dr. Colman to clarify issues.
DR.
FOLLMAN: Yes. I had one question. You said in the early 1990s you switched from
using or thinking you should use fractures as an endpoint in your studies to
using bone mineral density and the reason for this was given on the basis I
assume strong epidemiologic data. When
you went through that, was consideration given of the minimally effective bone
mineral density difference between the two groups? I'm thinking perhaps that you could end up
with a statistically significant change between placebo and a hormone
replacement therapy that wouldn't really be large enough to reduce the fracture
risk. So I just wanted to know when you
made the change, was consideration given to that issue?
DR.
COLMAN: Luckily, people were still
studying doses that were what we would perhaps consider too high now, but back
then they were the standard doses. We
didn't see a situation where after two years of study there was a half or a one
percent difference between drug and placebo, but it was powered to the point
where you could still get statistical significance. We did not put an absolute minimum on the
difference.
DR.
SCHADE: Just for clarification, you
mentioned this approach using DESI, a term that I hadn't heard before. Is that something that's still used by the
Agency or is that just historic?
DR.
COLMAN: That's historic. It was done around 1962 because up to that
point, drugs approved by the Agency, they only had to show some kind of
rudimentary safety. People thought we
have to look and see how efficacious they are. So the Agency actually
contracted with the National Academy of Sciences to look at hundreds of
drugs. They put together groups by
discipline to review the drugs and review whatever literature out there that
was on the efficacy of the drug. That's
how they came up with these classifications, probably
effective/ineffective. It's an old
classification scheme back in the 1960s.
DR.
LUKERT: If I could just take advantage
of gray hair to amplify Dr. Colman's comment about the response to the question
about why estrogens were considered approvable for osteoporosis prevention or
treatment on the basis of bone density whereas the drugs that were in newer
classes of the time of the guidance were not, the estrogens were not at all
suspected of having any effect on bone quality that would disrupt the
relationship between bone mass and bone strength. Whereas concerns had arisen about, for
example, fluoride. So the drugs that
were unphysiologic, if you want to put it that way, were held to a higher
standard when we developed those concepts, but estrogen wasn't considered to be
in the same situation at all. But again,
no specific magnitude could be identified.
CHAIRMAN
McCLUNG: Other comments for Dr. Colman
or questions? Thank you very much. We now turn to the presentation by
representatives from the Women's Health Initiative and let me first thank Dr.
Rossouw and the team of people he's put together to allow this to happen. There's an integrated set of presentations
that will happen, some before and others after the break. Let me propose to the Committee that we
listen to the entire set of presentations and then we'll have time for
questions, queries and discussion with the WHI individuals after that. Let me first introduce Dr. Jacques Rossouw to
lead off the discussion from the Women's Health Initiative Investigators Group.
DR.
ROSSOUW: Thank you. My job is to set the scene for my colleagues
who will give us some detail. What I want to put before the panel is the
reasons why NIH did this study, why this particular drug was chosen for the
study, why this particular population was chosen for the study and the snapshot
of the baseline characteristics of that study population to set the scene for
my colleagues who will discuss the trial design, the results and some interpretation
of the data.
The
trial that we're going to be discussing of the WHI is part of a larger
entity. There are also in that WHI
trials of dietary modification to look at whether there's reduction in certain
cancers and calcium/vitamin D aimed at fracture reduction and a very large
observational study. There are two
trials of hormones as was here. We're
going to talk about the estrogen plus progestin trial alone. The study is conducted in 40 clinical centers
across the country and a coordinating center.
Now
the issue of why did NIH do this study is best addressed by looking at the
state of knowledge in the early 1990s when this trial was designed. I'm going to try and illustrate that with
this rather complex slide, but I just want to point out a few details
here. The blue line represents the
prescriptions in millions of estrogens over time starting in 1960 and the black
line the prescriptions of progestins over time.
As
we've heard the use of estrogen to treat menopausal symptoms was approved way
back in 1942, but the uptake of estrogen in the general population wasn't that
big until the 1960s when there was a huge increase. It's interesting that the increase occurred
in the face of rather negative news on the scientific front. By that time, we knew that oral
contraceptives were associated with cardiovascular problems and conjugate
equine estrogen in men in higher doses did not prevent, in fact, increased
clots and heart attacks. But
overwhelming that apparently was a popular conception to which Dr. Wilson's
book, Feminine Forever, appeared to contribute that hormones were
generally good for womenkind.
So
the cells rose dramatically and then dipped in the mid 1970s when it became
known that estrogen alone caused endometrial cancer by some observational
data. It increased again when it became
known that progestins could prevent that increased endometrial cancer. So in the 1980s we saw a rise now
concomitantly with a rise in progestin prescriptions. In the 1980s, we also
learned from observation studies that the benefits appeared to outweigh the
risks. Estrogen use was associated with
lower CHD ("coronary heart disease") risk and with a lower fracture
risk. However it was also associated
with a higher breast cancer risk.
Because CHD is the predominant cause of mortality and morbidity in older
women, the benefits were thought to exceed the risks. At this point, NIH became
interested in doing a trial to see whether the cardiovascular benefits indeed
were real.
Now
in 1991, this is when specific planning for WHI trials started. In 1991 that was also the era when evidence
by medicine started dominating thinking in the scientific community and the era
of large randomized controlled clinical trial.
From the early 1990s then, a series of trials were launched. PEPI was the forerunner of WHI. The intermediate outcomes looked and generally
found favorable results. And HERS was
also planned, a second prevention trial.
As we now know, that didn't have positive trials for CHD and WHI was
planned. So from the early 1990s on, we
started getting into a higher standard of evidence and WHI is part of that
higher standard of evidence. That's what
we're going to be talking about.
Now
at the time when this study was being planned - I must also say there was as
you see an increasing use of estrogen in that period of planning - the interest
in looking at hormones for preventing heart disease were based on a substantial
body of data including small trials of the biological effects looking at
surrogate markers such as lipids and bone density and that all looked very
positive on average on some animal model data and on a large, growing body of
epidemiological evidence such including some of the best studies ever done
including cohort studies. But what was
deficient was a large clinical trial with disease endpoints. That was our thinking in looking at whether
this should be studies.
Now
part of that background, you don't have to look at the details here. I just wanted to illustrate to you how large
the evidence base is for thinking that estrogen only will prevent coronary
heart disease. This is a review done by
Barrett Connor and colleagues in 1998.
Some of the cohort studies which are the higher quality studies were
known at the time when WHI was being designed.
All of these were known. If you
summarize the data, there was about a 40 to 50 percent apparent reduction in
risk associated with estrogen only use.
That was the primary source of evidence driving the need for the trial.
At
the time that we were designing this trial, there was very little known about
the use of combined hormones, estrogen plus progestin, and its association with
CHD. Some studies emerged during the
development of the study. Except for
that one, these are all in the 90s. That
was a small clinical trial. So there's
very little known, but when the data came out, the relative risk was very
similar on average to that which was found for estrogen only. That was our assumption going in that. If there was an estrogen only effect, we
would probably find the same or maybe a slightly attenuated effect based on the
lipid changes for estrogen plus progestin.
However,
we were aware as you are that women who used hormone may differ in several
characteristics from those that don't especially those that use over an
extended period of time. Hormone users
are generally less obese, less likely to smoke and to consume a high-fact or
high-salt diet, more physically active and more highly educated. That came out in some of these observational studies. They are also more likely to go to doctors
more regularly and have health checks done and treated and some of our
treatments actually work so that may have help prevent CHD and have mammograms
and other screening. So there's a
surveillance bias and a healthy user bias.
They are also more compliant if women who use hormones for a long time,
maybe more compliant in other ways and therefore have healthy lifestyle and
other attributes that are not measured typically in observational studies. Of course the long-term hormone users, we
have to remember, are the successful users. These are the folks who
haven't had an adverse effect. So they
are going to look pretty good compared to non-users on average.
The
question was whether these differences could explain why hormone users appear
to have a lower CHD risk. Is the CHD
risk reduction real or is part of all of it due to these various biases?
Subsequent
to WHI being launched, a substantial number of second prevention trials were
published. Here are six of them. We don't have to look at the detail. I just wanted to point out that the clinical
outcomes of the secondary prevention trials.
None of them showed any benefit for CHD or stroke. They either
showed no benefit or no benefit and early harm.
The secondary prevention hormone therapy whether it's E or E + P doesn't
work and maybe harmful. That emerged
while we were conducting the primary prevention trial.
The
actual idea that NIH needed to do a trial of hormone therapy and CHD started in
the mid 1980s and panels were brought together.
Expert advice was sought. The
outcome of that was that the PEPI trial was done as a forerunner. Generally hormone therapy was then regarded
as a promising but unproven treatment intervention to prevent CHD. Against this background of increasing use by
millions of healthy older women, it was of concern that the overall benefits
and risks were not known. Therefore
there was this need for rigorous clinical trial. PEPI was started. HERS was started. HERS was not an NIH supported trial and WHI
for prime prevention.
It's
often said and we heard it today that
WHI studies the wrong population.
Well, it actually studied the right population for the question it was
asking which was "Whether hormone therapy is a suitable treatment in older
women to prevent chronic diseases".
In the mid 1995s to illustrate that point - and it was being used
increasingly for those diseases - NHLBI did a survey and found that 85 percent
of doctors - these were non-gynecologists - were prescribing hormone therapy. All gynecologists were prescribing hormone
therapy but two percent of non-gynecologists were prescribing hormone therapy. Of those who prescribed hormone therapy, 93
percent did for so menopausal symptoms, 91 percent for osteoporosis, 41 percent
for high blood cholesterol and 66 percent for CHD prevention.
At
that time you will recall both the National Cholesterol Education Program, AHA,
ACC, all of these bodies recommended hormone therapy as a treatment for lipid
disorders and for CHD prevention. That
was the climate in which we were operating.
In fact, it was quite difficult to recruit for WHI in the early 1990s
because many physicians advised their patients they should not enroll because
all women should have this therapy. So
that was the climate. There was
increasing use of hormone therapy to prevent CHD.
Now
why did we choose this particular drug?
Conjugate equine estrogens, Premarin, in the U.S. was and is the most
commonly prescribed hormone therapy and in women with a uterus, MPA is the most
commonly prescribed added progestin.
Initially this was cyclic. Now
it's predominantly in a continuous form in Prempro.
An
important point from our point of view was that most epidemiologic data on CHD
risk reduction in hormone users is based on the use of Premarin 0.625 mg. The well-known Nurses Health Study for
example 66 percent of the data in those analyses are based on Premarin. Most of it is at the dose of 0.625 mg where
they looked at the dose of 0.3 mg in their most recent publications. Their findings for CHD were similar. They weren't better or worse. They were similar. Now I've stated the data on combination
therapy and CHD emerged later, but when they did, they looked similar for CHD
to that for estrogen only. We didn't
have specific data for Prempro.
Let
me move on to the study population then.
Why did we choose this study population?
They were post menopausal. They
were a wide age range of 50 to 79. We
wanted to make it as inclusive as possible and as representative as possible of
the greater population of post menopausal U.S. women. So we made an effort to enroll minority
women. We had this wide age range.
We
had very liberal inclusion and exclusion criteria so we included women. We had no exclusion criteria for women with a
high body mass index ("BMI").
Except for very extreme levels, we did not exclude those with CVD risk
factors or with previous CVD provided it wasn't recent CVD. We did not exclude those with prior hormone
use.
Let
me turn then to some of the characteristics of the women that we did
enroll. The mean BMI was 28.5. However when you look at that and break that
into categories of normal weight, overweight and obese, you'll see that just
over 30 percent were not overweight or obese.
The results as we'll show in subsequent presentations apply to the
non-obese and the obese generally speaking.
To make a statement that the average BMI was 28.5 misses the point. We tried to make this enrollment as wide as
possible to be as representative of the population as possible. Where feasible we do subgroup analyses. So far we haven't found any subgroups that
have a moderately different experience than the overall.
Similarly
for the age, this is the age distribution on the left here. 5.5 thousand (5,522) of 50 to 59.
Even though the average was in the 60s we have the largest trial ever of
women in their 50s. We also of course
have very important information on older women.
We didn't have that many women with past or current hormone use. The majority had never used hormones before,
but we are able to do some analyses by prior use.
We
include women with risk factors. Here
are the percentages who were smokers, diabetic, hypertension, hyperlipidemia,
used statins or ASA. 6.2 percent had
prior CVD. I would point out however
that these numbers are all quite a bit lower than what you'll find in NHANES
surveys. This population on average was
indeed healthier than the average post menopausal population.
That's
borne out by the fact that our CHD rates were about half of what we had
predicted when we started the study. I
would also point out that almost 2,000
of the women did have moderate to severe menopausal symptoms at baseline and
that or the body mass index or the age or the years since menopause, any
subgroup that you want to look whether they had risk factors or not, we have
not been able to identify any subgroup that has a markedly or significantly
different experience than the group overall.
Having
set the scene, I would now like to ask my colleague Dr. Marsha Stefanick, the
Chair of our Steering Committee, to show you the most important results and
updates of the study. Mr. Chair, is that
okay?
DR.
STEFANICK: Thank you very much. It's a pleasure to be here. I'll try and be brief in this presentation. First of all, I would like to state that the
specific aims as you know were to test whether estrogen plus progestin or
estrogen alone reduced the risk of CHD defined as non-fatal MI and CHD death or
other CVD like stroke, increases the risk of breast cancer and reduces the risk
of hip and other fractures. But also of
equal importance to us was to determine the overall balance of health risks and
benefits of E + P and E alone.
Women
were randomly assigned based on their hysterectomy status. If they had a hysterectomy, they were
assigned to either CEE at the dose 0.625 mg, essentially Premarin, or to
placebo. If they still had their uterus,
they were assigned to combination therapy, the same estrogen combined with medroxyprogesterone
acetate or placebo. Initially there were
a small group of women who were assigned to a three-way randomization. Prior to the PEPI results when the PEPI results
came out, the estrogen only arm was discontinued and women were converted to
the combination therapy.
The
outcomes monitored by the Data Safety Monitoring Board ("DSMB") were
three cardiovascular endpoints, CHD, strokes, pulmonary emboli; three cancer
endpoints, invasive breast cancer, colorectal cancer and endometrial cancer;
hip fractures and deaths from other causes.
In addition, the global index that you've heard about was defined as the
earliest occurrence of each of those events to provide the overall balance of
risks and benefits.
As
you may realize, the DSMB actually requested that the investigators inform the
women after most of them had completed two years of the trial that there was an
unexpected finding relative to our hypothesis that there was actually an
increase in the number of heart attacks, strokes and blood clots in the lungs
and the legs in the women receiving active hormones compared to women taking
placebo. So all the participants in the
hormone trial were alerted to this information.
A
year later, the DSMB required that we inform the women that now that we had
completed an average of four years of the trial these excess cardiovascular
events persisted in the active hormone group compared to the placebo. All of these data were based on the combined
E only and E + P trial data. The
investigators were never informed, nor were the women, what was going on with
the E only trial. As you all know last
year, May 2002, the NHLBI accepted the DSMB recommendation to stop the E + P
trial after an average of 5.2 years because the risks exceeded the benefits
based on the monitoring rules which Dr. Anderson will elaborate on when she
presents her presentation.
In
particular, I do want to point out that we are following these women so they
are still being monitored through the trial.
They are just not taking their hormones at this time so that we can get
information about the long term risks and benefits. Also the DSMB recommended that the E along
trial continue because the risks and benefits were not yet certain and the balance
was not clear. We were able to inform
the women at that time that there was no increased risk of breast cancer by the
5.2 year period and we do continue to monitor these women closely. They are continuing to take their study
pills.
To
just focus on the E + P trial results then, in the publication from last July,
we published both the nominal confidence intervals for the hazard ratios for
each of the primary events and very conservative adjustments based on the
sequential monitoring and the multiple outcomes. To just point out as you see, there was a set
of clear harmful events, CHD, stroke, breast cancer and pulmonary emboli and
there were a series of benefits, colorectal
cancer, hip fractures. Also shown
here are total fractures. Death was
neutral.
These
were all presented in the paper last year to actually focus on the global index
which was this overall balance. The main
point I'd like to make by showing only one of our many Kaplan-Meier curves is
that when we look at the accumulated incidence as we add these up, at no point
were the E + P women better off than the
placebo. The placebo were always having
a lower overall risk ratio relative to the benefit. The main point is that the risk clearly
exceeded the benefits in the active group.
Also
presented in the paper were the annualized event rates for the primary
outcomes. What you see is that the
excess risk attributed to E + P for every 10,000 women were seven more for CHD,
eight more for stroke, eight more for
breast cancer and eight more for pulmonary emboli. And the attributable benefits were six lower
colorectal cancer, five fewer hip fractures, neutral for endometrial cancer and
neutral for death.
These
were the events that we published last year.
This basically came out to an overall summary of 19 health problems for
10,000 women assigned to E + P versus placebo which essentially means that over
five years there was a net per 100 women in the active treatment group who had
a harmful outcome. Our conclusion was
that treatment with E + P for up to five years is not beneficial to overall
health.
Since
that time, we've been publishing the more extensive data. We actually had four months more of outcomes
but they had not been adjudicated and not built into the analyses when we
published the data last year. Two of
them I'll elaborate a bit on, the coronary heart disease risk and stroke. You'll hear from Rowan Chlebowski the breast
cancer data and Jane Cauley the fracture data when I complete my presentation.
What
I'd like to do is start out first of all with the basic principle of these
updated papers. We now have a mean of
5.6 years of follow-up. That's the
actual length of the overall follow-up time which means that we have more cases
for all of the events that were published last year. In addition, all of the major events have
been centrally adjudicated. In the case
of the CHD update by cardiologists, in the case of stroke by neurologists and
so forth. In addition, we have
additional endpoints relevant to the outcome in question and we have analyses
on subgroups trying to get information about many of the questions that have
come our way in terms of "Are there groups that are better off and are
there groups that are worse off".
With
respect to the CHD, the main point that I'd like to make from that paper, the main
issue I'd like to summarize, is that when we looked at all the data, first of
all, I'll point out that the hazard ratio from the updated centrally
adjudicated data is 1.24 so 24 percent increase in CHD. But the most important point that I'd like
make is this was particularly elevated in the first year. The hazard ratio of 1.81 appeared in the
first year.
What
you see is that each year of follow-up where the first event is no longer
included in each of the next years we still have an excess risk in Year 2, Year
3, Year 4, Year 5 in the E + P group.
Not until Year 6 when the placebo group had essentially caught up at
this point - They've been surviving all of this time. They now have their heart attacks - that's
really the explanation for this reverse of the hazard ratio in the years after
year five. At least that's my judgment
of it.
Now
I would like to point out that there had been many studies showing benefits to
lipids from E + P and E only starting before the PEPI study but the PEPI study
certainly emphasized that. We did see
those in the subsample of women for whom lipids were measured. We did see a decrease in total cholesterol
and LDL cholesterol of 12.7 percent, very similar to data published
previously. There was also an increase
in HDL cholesterol of 7.0 percent which was actually a little bit better than
the PEPI study. We also saw decreases in
glucose, not significant, but also insulin. So the lipid benefits that
we've talked about were also seen in WHI, but I think we all recognize that
this is a risk factor for a disease. The
disease was not benefitted. So in this
case, we have to recognize that looking at lipid changes is not the appropriate
approach with respect to CVD and hormones.
Also
just to quickly mention in all of the analyses that are coming out, we are
looking at lots of subgroup analyses. In
the case of CHD, age, years since menopause, hot flashes, with and without
night sweats, obesity status, race, ethnicity, education level, all of these
have been examined and none of them have shown any effect in terms of the
interaction. So there is no evidence
that these things make a difference with respect to the overall risk associated
with E + P.
Similarly
we have a large list of biomarkers and other risk factors. I will point out that one risk factor did
show up as significant. LDL cholesterol,
the higher the level the more likely you were to have a coronary heart
attack. But I also want to point out
that there were so many subgroup analyses done that we can't say this wasn't
due to chance. By the time you've done
20, you have one out of 20 that could be by chance. But at any rate, we've gone to quite a bit of
effort to look for subgroups that may be
better off or safe. At this point,
everything pretty much comes out to the same answer that the risks exceed the
benefits.
I
also want to point out that with respect to CHD whether women had an event in
the past or whether we talked about a more comprehensive cardiovascular package
or the CHD alone, we still have a net risk associated with that. So also history of heart disease did not make
a difference in the risk associated with E + P.
In
the stroke paper, we basically elaborated on the fact that ischemic stroke in
particular was the stroke that was increased.
So where we would look at total stroke, we have a relative risk of 1.31. Ischemic strokes, it's 1.44. Hemorrhagic stroke is not significant. There weren't as many hemorrhagic strokes. As you see, the vast majority of strokes were
in fact ischemic strokes.
In
summary from the stroke data, we now basically continue to say that we have
excess risk. Seven per 10,000 women per
year are having strokes attributable to E + P in our data. The excess risk is not explained by blood
pressure increase which I failed to point out that we did see. It was apparent in hypertensive and
normotensives and it was apparent in all the subgroups that were examined. Also we looked at quite a few biomarkers and
there was no significant interaction on the biomarkers.
Also
quickly, we now published the gynecological cancers. Dr. Anderson is here
today. You'll be hearing from her. Other papers have been submitted and are
forthcoming but we do not yet have the data published. With respect to the gynecological cancers,
invasive ovarian cancer, 32 cases; hazard ratio of 1.58; confidence interval,
not significant. Endometrial cancer, 58
cases; hazard ratio. 0.81; confidence interval, not significant. There were relatively few cases of these
cancers with a suggestion of increased risk for ovarian cancer and a suggestion
of decreased risk for endometrial. No
appreciable differences in the distributions for tumor histology, stage or
grade for either of those cancers. In
the case of cervical cancer, there were 13 cases out of the 16,000 plus women
and the data and the trial are really too limited to say very much more about
that.
I
do want to point out that we did have relatively high discontinuation rate for
pill taking. That's been discussed in
many settings. You see that over the
course of time an increasing number of women were coming off the pills in both
the placebo group shown in yellow and the active group shown in orange. But also there were an increasing percent of
women going on estrogen and progestin.
So that what you see below is the women who are coming off the pills
here as a substantial portion of them were going on exactly the same medication
but open label with their own physician and twice as many women in the placebo
group were falling into that category. When we actually look at all of the data I've
talked about so far and look at the data by intention to treat, we have a 24
percent increase in CHD, 31 percent increase in stroke, 24 increase in breast
cancer in the updated analyses. But when
we add on to that the compliance data looking only at women who were taking at
least 80 percent of their pills and censoring the event history for six months
after they stopped taking pills, what you see is that in fact 50 percent higher
CHD, 50 percent higher stroke and 49 percent higher breast cancer. When we actually look at the highly compliant
women, the risk attributed to these hormones is even greater.
I'm
not going to say anything about the quality of life data. I do want to say a few things about the WHI
Memory Study ("WHIMS"). It's
been pointed out and I'll point out again that this was an ancillary study
restricted to women who were 65 and over at baseline and included about
one-fourth of the overall study population, 4,532, with more than 90 percent of
the women who were eligible to be in that trial actually participating. So it was a fairly good representative study
group. Essentially the data that we have
from that study shows that probable dementia happened twice as often. It was diagnosed twice as often in the E + P
group relative to placebo. We actually
looked at the rates per 10,000. It was
45 per 10,000 in E + P and 22 per 10,000 for the placebo which is essentially
23 excess cases per 10,000 women per year.
Dementia twice as high. Mild cognitive
impairment ("MCI") was actually not different between the two groups.
So
come back to our new summary, we're slowly improving these risk estimates. We now can lay out that we have eight more
women with breast cancer per 10,000 per year, six more with CHD, seven more
with stroke. We have not yet published
the updated data for pulmonary emboli or for colorectal cancer in which there
were six fewer, but we have published the updated data now for hip fractures
which is five fewer. So we are still in the
area of over a five year period one in 100 women are having unhealthy events
related to these hormones.
We
essentially stand by the same implications that we published last July. The overall risks of estrogen and progestin
outweigh the benefits when taken to prevent chronic disease in post menopausal
women. Estrogen and progestin should not
be initiated or continued for primary prevention of coronary heart disease and
the risk for CHD, stroke, pulmonary emboli and breast cancer must be weighed
against the benefit for fracture in selecting from available agents to prevent
osteoporosis. With that, I'm going to
turn over to my colleague, Rowan Chlebowski who will present the breast cancer
data.
CHAIRMAN
McCLUNG: Actually, let me take the
prerogative of suggesting that we actually have our break at this point because
we're come back after the break and talk about specifics about breast cancer
and about bone disease. Plus we're
halfway through the morning. Let me
propose that we have our 15 minute break, reconvene at 10:25 a.m. to continue
this discussion. Thanks. Off the record.
(Whereupon, the
foregoing matter went off the record at 10:12 a.m. and went back on the record
at 10:31 a.m.)
CHAIRMAN
McCLUNG: On the record. Let me invite Dr. Chlebowski to the podium to
continue the presentation of data from the Women's Health Initiative and to
specifically address the more detailed analysis of issues related to the breast
cancer risks.
DR.
CHLEBOWSKI: Thank you very much. I also am delighted to be here and to give
you a little bit more detail on breast cancer in the WHI. Menopausal hormone therapy in breast cancer
as we've heard about CHD also has an extensive background. There were numerous observational studies
suggesting that longer duration usually meaning by definition, - short duration
used to be five years or less of use - would result in increased breast
cancers. There were suggestions that
these cancers would found at low stage and have favorable prognosis, the
receptor positive predominance and more lobular in histology. In essence, the thrust was that E + P or
hormones would offer an earlier diagnosis of cancers which would otherwise
anyway come forward.
When
we talk about the WHI, you heard much about the characteristics of the
population. I just list here a number of
the things that we captured in terms of known and presumptive breast cancer
risk factors. We won't go over all these
data except to say that none of these characteristics differed significantly
between treatment groups. So we have
much breast cancer risk information.
One
point that's already been made by Dr. Rossouw that I want to point back up
again in this setting because one of the issues we'll be attempting to get at
is the duration issue in breast cancer is how about prior hormone usage. As you've heard before three-fourths of the
women had never prior hormone exposure.
About six percent were current users.
Those users had to wash out or stop therapy for three months before
beginning their baseline evaluation.
One
of the things that's different again from the WHI Randomized Perspective Trial
were the issues about case ascertainment and breast safety. So baseline mammograms and clinical breast
exams were required for eligibility.
Everyone was screened before entry.
Annual mammograms and clinical breast exams were required when on study
and importantly the dispensing procedures would not allow dispensing of the
medications if safety procedures were not done.
So if a woman didn't have a report of a mammogram within a window, at a
time for dispensing she could not be dispensed further medication until she did
get those studies.
Here's
the summary of the major results which is again updated from the original
publication. This data was published in JAMA
of June of this year showing that on E + P there was a total of 245 versus 185 cases.
Dr. Anderson who will follow me will go into more detail about the
statistical analyses involved. Here we
have invasive breast cancer 199 versus 150 with a hazard ratio of 1.24 and just
a trend of insight to cancers. Those
were the numbers of invasive cancers that we saw on E + P during a course of
follow-up that ended after 5.6 years.
Here's
what the Kaplan-Meier curves look like.
We'll come back to some of these duration issues. Again unweighted hazard ratio 1.24. You can see actually that the curves cross at
about four years and then more E + P data.
We'll look in more detail at the hazard ratios in the first two to three
years where there was an apparent lower incidence of breast cancer seen on the
placebo compared to the E + P arm.
Similarly
to what Dr. Stefanick showed as well, we did a sensitivity analysis to perhaps
allow a better comparison to some of the existing observational study
data. Again what we did was participants
were sensored six months after becoming nonadherent. That is not taking 80 percent of their study
medications or taking non-protocol hormones.
What you can see here is that our hazard ratio is now 1.49 with a
earlier departure deviation of the two curves.
We
looked at many subgroups, none of which really showed a different relationship
of E + P to development of breast cancer.
I'll just show a couple of these.
This is a breakdown by age. You
can see that actually this is a test for interaction. There
is no interaction, 1.2 in the 50 to 59 year olds, 1.22 in 60 above. So basically it wasn't as if only the older
individuals were at breast cancer risk.
Because
there'll be more detail gone over in the BMI portion for fracture, we include
this to look at the breakdown of hazard ratio for development of breast cancer
by BMI. The trend was actually
nonsignificant, but there was an appearance that maybe in the older individuals
there was somewhat less of an effect on E + P to increasing breast cancer
risk. Again that interaction was not
statistically significant.
Dr.
Anderson will go in much more detail over issues of prior menopausal hormone
therapy exposure. I'll just show you
this one illustration of the overall breakdown of no prior hormone therapy
versus ever prior hormone therapy. You
can see the P-value is 0.10 so the interaction wasn't significant. More breast cancers on E + P in both groups,
a nonsignificant trend. Ever users were
at somewhat lower risk. We have a
question which we'll go into more detail with at a later presentations about
cumulative exposure versus selection bias.
We'll
point out a couple of those issues here.
Here's the women with no prior menopausal hormone therapy E +
P/placebo. Their hazard ratios in the
first year were 0.48, 0.65. So like a 50
percent apparent reduction in the first two years for E + P compared to
placebo. You don't see that in the women
with prior menopausal hormone therapy.
Now the other additional issue is this will provide one possible
explanation for this because this prompted our look at the mammogram data
subsequently.
If
we look at the breast cancer characteristics by group, remember there was a
suggestion from especially more recent observational studies involving E + P
that lobular cancers would be largely responsible for most of the
increase. Actually we saw nothing like
that. We saw really that all types of
cancers were the same in both groups.
Again the suggestion on the predominance of the observational studies
that E + P would be associated with well differentiated cancers wasn't
seen. We saw the same distribution,
similar histology and grade on E + P compared to that on placebo.
How
about the receptor status? What we see
here is that both receptor positive and negative breast cancers were greater on
E + P. This number tests the interaction
between E + P for receptor status. You
can see more receptor positive cancers, more receptor negative cancers, more
progestin receptor positive cancers, more progestin receptor negative
cancers. The P-value suggests that there
was a significant imbalance with respect to the number of individuals having
receptor status determined. This wasn't
based on size difference. We don't have
an explanation for that imbalance. It
appears that both receptor positive and negative breast cancers were greater on
E + P.
Now
this is an important data demonstration because very surprising compared again
to the observational study data, we saw that actually instead of being more
favorable stage, the tumors on E + P compared to placebo were larger. This difference was statistically
significant. It was more likely to have
node positive and more likely to be at regional stage. More advanced stage was seen on E + P. I think the other thing I can point out that
this is what you get when you have a population that has 90 percent of that
population has yearly mammograms. You
get an average size on the placebo of only 1.5 cm. So the cancers were larger, more likely to be
node positive on the E + P arm.
This
finding of similar grade, histology, and receptor status but more advanced
stage where ascertainment was felt to be equivalent and that suggestion that
there were apparently fewer cancers seen in the first couple of years on
hormone prompted us to look at the mammograms.
Basically it's our mammogram findings after one year on E + P.
As
you can see, 90 percent were normal, but the abnormals were 9.4 percent versus
5.4 percent on placebo. This is a relative increase of 74 percent in
abnormal mammogram frequency after one year.
Most of those abnormals were in the short interval follow-up category,
Category 3, but you can see that suspicious abnormalities usually leading to
biopsy were also higher.
This
finding persisted. This is the data you
saw before. This is the mammograms
abnormal, 9.4 versus 5.4 compared to the baseline of about five percent in both
groups. The cumulative after six plus
years of follow-up were 30 versus 21 percent. This is the frequency of
mammograms by arm. You can see that
after the first year 90 percent of the women had their assigned mammograms and
the cumulative goes up to 97 percent.
The people that would drop off that wouldn't be required to have
mammograms before dispensation. That
wasn't an issue. What we have there in
summary was that abnormal mammograms were associated with even one year of E +
P use, a four percent absolute increase in abnormal mammograms after one year
on E + P, a ten percent absolute increase in abnormal mammograms after about
five years of E + P.
Now
to inform some of these results especially our finding of more advanced stage,
we can get some information from the recent results from the United Kingdom
Million Women Study. This is based on a
National Health Service Breast Cancer Screening Program trial in the United
Kingdom. What their study involved was
the National Health Service there invites all women in the United Kingdom 50 to
69 years of age of have a screening mammography every three years by
letters. A questionnaire regarding
hormone therapy use was added to the screening invitation letter. The women showed up for their screening and
then the data on their hormone therapy use was linked to National Health
Service Central Registries for Breast Cancer and Death Outcomes. 1,084,110 million were identified and 9,364
invasive breast cancers were seen. I
should emphasize this was a perspective cohort study. It was not randomized. It was very large.
What
did they see? Now they included if women
had an abnormal mammogram at baseline and were taking hormones one year
before. They would be considered to be
on hormones for one year and that work-up would count. So they didn't screen and eliminate
cases. They included everyone. But when they did this, the relative risk of
developing a fatal breast cancer by hormone therapy use at baseline had a
relative risk of 1.22 which was statistically significant. They found that hormone therapy was
associated with increased breast cancers and
mortality in short-term users. By
short-term users, it means they were based on deaths after follow-up of 4.1
years.
How
about the duration effect? Again it's
really quite different than the WHI in that there's a number of
differences. They included the work-ups
down on baseline. Because they had
mammograms done every three years and they reported the incidence data after
2.8 years, the majority of these cases would not be screening detected cancers,
but would rather be clinically detected cancers without mammographic screening. By this, they get rid some of the
ascertainment issues. What they saw was
after one year a relative hazard ratio of 1.45 going up over time. This is the data for their E + P which was
associated with increased breast cancer risk in less than one year.
How
about the hormone types? Without showing
all their data, they saw an increase also with E only for all types of estrogen
but the risk was substantially higher for their E + P combinations. About one-third of the women had conjugated
equine estrogens, Premarin, and they had a relative risk of 1.29,
conventionally significant. But other
estradiol was also significant and besides medroxyprogesterone acetate, other
progestins also were associated with increased breast cancer risk.
So
our conclusion based on these combined findings is that combined E + P use
increases breast cancers, diagnosed in more advanced stage and increases more
abnormal mammograms. These results
suggest that use of E + P may simulate breast cancer growth and hinder breast
cancer diagnosis. Thank you. The next speaker will be Dr. Garnet Anderson
who will be going over more details of the prior E + P users.
DR.
ANDERSON: Good morning. It's a pleasure to be here. On behalf of colleagues, I wanted to cover
the statistical methods issues, and I'll try to do that in short order because
I know that's not what most of you get up early in the morning to hear. Then I will cover some of the further
analyses of prior hormone therapy and breast cancer risk. These are questions that have been
specifically put to us by members of the FDA.
On
the statistical methods, I wanted to point out to you that the design and the
primary analyses of all of our clinical endpoint data is based on a weighted
log rank statistic which I've shown here.
It can be written in the usual observed minus expected notation. This is trying to look at the difference in
survival curves or incidence curves over time.
The only thing that's unique about this is the weights which is
signified here. So I wanted to describe
what that means.
These
weights are specified for each disease endpoint. The motivation is not to weight different
diseases because that's a very difficult place to go. Rather these weights are defined by time
since randomization. The motivation is
actually to increase the efficiency of the study group at power. It was based on the idea which is common in
prevention trials that the intervention effects will not be fully manifested
right away. It will take some time for
the differences in clinical endpoints to appear.
Let
me show you the actual weight we used.
So any differences you see in the early period are more likely to be due
to a random occurrence than to be a true treatment effect. We actually had very good observational data
to say that the effect of hormones on breast cancer may take a considerable
amount of time to be fully manifested.
So
the weights for breast cancer were defined to be linear over a ten year
period. The differences observed in the
first year or so would have very little weight but increasing over time. Differences at year 10 and beyond would have
full weight. That was the weighting
scheme for cancer and also for mortality or global index calculations.
For
CVD and fractures, the data were not so clear.
In fact, the observational data tended to suggest that it was current
use of hormones that was protective for CHD.
Nevertheless a lot of the hypothesis came through the intermediate
effects of lipids which though that might be rather immediate but its
translation into a clinical impact could take some time. After quite a bit discussion, we used a
three- year weighting period. By the
time, we got to the three years any events occurring after that would receive
full weight.
That
plays into both the analysis and it also played into the monitoring plan. Dr. Rossouw gave us a nice summary trying to
understand where we were when we designed this trial. It was a prevention trial. In developing our monitoring plan which the
development has been published back in 1996, we were thinking of the issue of
benefits and risks with CHD being a benefit that was at that time considered so
obvious that the question was "Could we really ethically continue this
trial when the benefits might accrue by year three in the study when we knew
the breast cancer results might take a fair amount of time to see".
The
monitoring plan that we used then and continue to use now for the E only trial
was based on that general idea. We would stop for evidence of CHD benefit
using a standard procedure that looks like the upper tail of 0.05 level test
with .025-level, one-sided test corrective for multiple looks over time, the
traditional O'Brien-Fleming procedure boundary.
This is exactly the same in many trials used for a single endpoint trial.
The
only catch to this is that we did develop the global index specifically for
this monitoring purpose. That was to
provide some measure of the risks and benefits balance at that time. Though we didn't require this to be as
significant or as clear - we only looked at the .05-level, one-sided test for
this - it was to be clearly weighing on the side of overall benefit to stop
this trial. That was the only way that
we would stop for benefit.
Stopping
for harm, there were actually two alternatives.
Breast cancer was our primary safety endpoint. There were prior data suggesting that this
might be a problem so we defined a monitoring boundary for it alone not
adjusted for multiple endpoints. Because
we were interested in proving harm to the same degree of precision as you might
want for benefit, the stopping level was a .05-level, one-sided test equivalent
to the .10 percent type one error again adjusted with O'Brien-Fleming procedure
for multiple looks over time.
If
that boundary were crossed and a global index which was supportive of harm,
that's a Z-statistic less than minus one.
So one standard deviation below the no-hypothesis, we would stop for
harm based on breast cancer. We also
defined similar stopping boundaries for all the other designated monitored
endpoints of CHD, stroke, PE, hip fracture, colorectal cancer, endometrial
cancer and death from other causes.
Death from other causes was just to pick up anything unforeseen that was
serious in terms of the health of women.
These use the same .05 level tests but it was corrected with a
conservative Bonferroni correction because we were looking at all those
multiple endpoints and didn't want to inflate our type one error by looking at
too many endpoints at once. Those are
our monitoring boundaries. It was the
breast cancer boundary and the global index boundary for harm that were crossed
last spring.
A
couple of other notes. All the analyses
we present are based on intention to treatment.
That means that every women randomized is analyzed and included the
analysis in the arm in which she was randomized regardless of whether she
stayed with that arm. Even our sensitivity analysis looking at
adherents do not cross the women over. They just sensor her data at the
time she becomes non-adherent. This is the best in terms of preserving the
ideal quality of a randomized trial.
We
do provide unweighted hazard ratios which is a bit of awkwardness given that
the trials were based on the weighted design, the weights over time. I would say that this was a compromise that
we made based on the fact that we were completely wrong about our CHD
findings. The assumptions underlying
that design were wrong. We didn't reach the
full preventive effect by year 3.
Then
what do you do with the weights? Mostly
when you don't have an idea of a time to effect you would do an unweighted type
of statistic. We do provide unweighted
hazard ratios and then associated with those, nominal and adjusted confidence
intervals. The nominal 95 percent
confidence intervals for those hazard ratios probably need no further
comment. The adjusted however taken into
account the fact that we did look at the data every six months for monitoring
purposes and we did look at multiple endpoints.
We think it's only fair to bring that note of caution into the
interpretation of these data.
Particularly
for breast cancer, we also in some places showed the weighted P-values,
P-values from the weighted analyses, because there is a discrepancy in the
interpretation at points when you take the weights into account and when you
don't. To be fair, the design and the
analysis for these endpoints did always indicate that we would use weighted
analyses.
A
lot of what we're doing today and have been doing in the papers since last year
has been looking subgroup analyses.
These are much more difficult to interpret statistically. In the process of working through these
papers, we've developed our own WHI sort of policy for how we'll interpret
them. It is that our inference will be
based primarily on the test of interaction.
The
trial was not designed to test this specific hypothesis within each subgroup so
we acknowledge that those specific subgroup tests within themselves are low
powered. That means we have a high type
two error. We also have a high type one
error. We've looked at many subgroup
analyses. It's possible to find some
that are significant by chance alone.
To
minimize this as best we can, our inference is primarily based on those tests
of interaction. Then we report unadjusted
P-values and we say that these should be considered as hypothesis generating,
not testing. Then we have asked each
author of each paper to report the number of interactions they tested and to
report the number that would be expected to be significant by chance
alone. We feel that it is a reasonable
approach to this area which is really very exploratory.
On
that note, let me go to the specific subgroup analyses that I've been asked to
address which is prior hormone use and breast cancer risk. I feel a little embarrassed to tell you that
I'm presenting this to you without having the WHI investigators as a whole to
be able to see this in advance nor our DSMB which will be reviewing some of
these data for the first time in a few weeks.
But that said, this is an important meeting for all of us so I will take
you through these realizing that they have not been digested by the WHI
research community as they normally would.
I've
been asked to look at more detailed analyses of prior hormone exposure including
type, duration and recency of use, the extent of the disease by prior hormone
use and a bit of mammography performance.
This is an amplification of what Dr. Chlebowski already showed. I'm sorry that some of these numbers don't
show up very well.
Looking
by prior hormone use and invasive breast cancer, the hazard ratio is 1.09. You've seen that before. In invasive cancer, the hazard ratio is 1.86. The unweighted P-value is .04. The weighted P-value is .10 suggesting some
modest evidence of an interaction with prior hormone use where women who have
been exposed in the past if you looked at that by itself these Z-values of -2.7
or -3.0 are clearly statistically significant.
Where you don't see that, it's just a slight trend of an increase in the
women who have not been exposed
previously.
But
what is rather curious about this finding and I can't explain it exactly is
that the rate of invasive breast cancer in women who have been exposed
previously but who then were randomized to placebo is quite low. It's 0.25 here. That's the annualized incidence rate. Placebo who are not previously exposed is
higher. It's 0.36. That's a little
bit curious and suggests to me some sort of selection bias probably in the
sense that these women are different, the prior hormone users versus the
no-prior exposed group.
These
are the Kaplan-Meier curves in those two groups. We should especially try to remember this one
because it becomes the reference group for many other analyses. You can see that the period in which the E +
P group has a lower incidence rate is at least for four and a half years, but
the curves do cross. The E + P group has
a slightly higher rate in the later years.
Therefore the pattern is overall the same but you see a longer duration
of lower rates. Whereas in the prior
exposed, the separation of the curves does begin much earlier by about Year 2.
Now
I want to break it down by type of prior exposure. Here I've categorized slightly differently
than it was in the JAMA paper.
Here prior E only exposure is only exposed to estrogen alone. These women never took progestin
before. Any prior E + P, some of these
women did have some episodes of E alone exposure. I wanted to keep the E alone group pure. This group is the women who had some
progestin exposure. You can the hazard
ratio. That's the same as before. In the prior E alone exposure, the hazard
ration is 1.47. E + P is 2.19. Unweighted P-value for the interaction is
0.08. The weighted is 0.17. So again there's some kind of suggestive
trends but not very strong. The
suggested prior exposure particularly prior E + P seems to be associated with
higher risk.
Again
we note that the women with prior exposure to E + P who were randomized to
placebo have a quite low rate, 0.19 percent per year versus the other two
groups with about 0.36 percent per year.
So women with prior exposure to E + P are clearly different.
Here
are those curves. Prior E alone
exposure, you can see that the crossover is about three years perhaps and then
the separation doesn't seem to really show up until Year 5. Whereas, prior E + P exposure the curves
differ around Year 3.
This
slide shows duration of use. Here we
don't see any strong trends. It looks
like the no prior use as before but the prior year 2, 2 to 4 or 4 plus years
was all in the same general area.
Unweighted P and weighted P are basically in the same region as we've
been seeing on those other slides, suggesting that maybe it is just yes-or-no
prior exposure. This is one of the questions
that was put to me. Is that really the
case?
Here
are those curves. I personally don't get
a lot out of them. They all show similar
pattern. There's maybe a slight
difference in where the curves start to diverge.
Then
the final one on this is recency of use.
Here is at initial screen. So
women who were using hormones at the time we first encountered them actually
had to go through a three-month washout period before they could be
randomized. These are women who were
using hormones before the washout period and then within the last five years
but not at the baseline visit five to ten years ago or ten plus years ago. You can see all of these are generally in the
same region. The P-values suggest that
there's no interaction between those.
There
are the curves. Hormone used at
enrollment within the last five years, five to ten years ago, and more than ten
years ago. Maybe the separation is
coming a little bit later for older use.
One
final question is the combination of prior use and BMI and I think this
motivated more by the issue of osteoporosis.
Here we have classified it by prior use and obese or not obese. You can see that prior use in the leaner
women - I'm not sure that's exactly the way we should describe it - the hazard
ratio is 1.18. No prior use and the
obese women we saw no elevation there in that hazard ratio. But the prior users both of those tend to
have an elevation. The P-values again
are not very strong suggesting it's modest evidence for any interaction
there. There are those four curves.
In
thinking about this though I was realizing that as soon as we start to make
inference about prior hormone use, we've left the framework of a randomized
trial. We're now starting to talk about
an observational study. So we looked at
the characteristics of the prior hormone users in this trial. We noticed a lot of the same things that you
all know from observational work. Women
who had used hormones before were younger, leaner, had a lot of characteristics
that make them different. Vasomotor
symptoms, parental history of fracture and had a mammogram in the last two
years, a variety of things. To what
extent could those issues be confounding our results?
The
other thing is in terms of looking at the different hormone preparations the
use of E alone or combined hormones the pattern of use is different in
particular. In about 26 percent of our
population, you can see that they had used hormones previously. A little bit more had been combined use. Here actually you can see overlap. The numbers don't add up because the woman
could be in either this category or that one or both. But women who had used E alone were more
likely to have a shorter term exposure to estrogen than women who had used
combined hormones.
A
stronger contrast is in recency of use.
E alone users 58 percent their exposure to E only was more than 10 years
ago. Whereas combined hormone users were
much more likely to be the current users.
Whenever we are looking at recency of use and we don't tease a power at
those two, we may be confounding that issue.
I
started doing multivariate models all of these things. Controlling for multiple confounders, this is
the E + P hazard ratio. I threw in just
about everything on that first slide, listing the differences and
characteristics plus additional breast cancer risk factors. So in that multiple variate model, the
unweighted hazard ratio is 1.2. That's
compared to the primary result of 1.24.
Separating
it out by exposure to prior hormones, you see in women with no prior exposure
the hazard ratio is now 1.02. Women with
prior exposure of any type is almost 2.0.
The unweighted P-value is 0.3.
The weighted P-value is highly statistically significant. Now we're getting some stronger evidence in
an observational sense that there is an interaction here.
This
is separating it out in the same type multi-variate model where the main
effects now separate out the type of prior exposure. Women who are only exposed in the past to E
alone their hazard ratio for E + P is 1.36.
Now don't confuse this as the E alone hazard ratio. That's not what this is. This is the E + P hazard ratio in women who
have been exposed to E alone. I know I
got confused when I put it against the Million Women Study because their E
alone hazard ratio is 1.3 or so. That's
not what this is. And prior exposure to
combined hormones is 2.46. The P-values
here are not so clear. Unweighted P is
0.05. The weighted P is 0.64.
This
is duration of use. Here you can see
that it now looks a little bit more like an orderly trend as opposed to our
unadjusted analyses. Less than five
years of exposure is about 1.8. Five to
ten is 2.14. Ten plus years of exposure is 2.53. Unweighted P is 0.08. The weighted is highly statistically
significant. I would say that these
tests are based on a continuous variable not in these categories so it doesn't
rely on us choosing the right category perfectly.
This
is recency of use. You can see that at
initial screen and last five years or five to ten years were all thereabout in
the twofold increase range. Last
hormones used ten years ago it starts to fall off. Now remember, this is any prior hormone
exposure. I haven't teased apart the E +
P and E alone. So this is mostly
reflecting an E alone prior exposure. In
fact, I couldn't fit them all where I teased both things apart like this.
This
is looking at the combination of prior hormone exposure and BMI. You can see the same basic trend where it
looks like women with no prior use who are obese are not at elevated risk of
breast cancer. Everyone else is
particularly those with prior hormone exposure and some clear evidence that
this may be real.
I
also want to look at effective disease by prior use and randomization
assignment. You see exactly the same
pattern in the size of these tumors in the women who are unexposed before the
trial and those who are. They are not
statistically significant because I've divided the sample size up here. But the same trend exists.
Percent
positive nodes in advanced stage show the same pattern in both groups but again
it's this weird thing where the placebo group in the women who had been exposed
previously have a lower percent of positive nodes and lower percent of advanced
stage than the placebo group with no prior exposure. So this is another very curious finding.
This
is the newest data. Women received
letters from us on July 8 of last year asking them to stop taking their pills
but we've continued to follow them up.
This is the increment of data since that time. They have not been taking our pills. Some of them have probably been taking their
own pills. But you can see that we've
had 21 new breast cancers in the E + P trial and 18 new ones in placebo for a
hazard ratio of 1.13. Our cumulative,
combining the intervention period with the post intervention period, is 227
invasive cancers versus 170. The hazard
ratio is 1.26, again especially by our weighted statistic, very highly
statistically significant.
Let
me try to summarize. We see a suggestion
of greater E + P hazard ratios in women with prior hormone exposure. I worry when I think about this by the
potential confounding of the differential characteristics of prior users. We've done a pretty good job of trying to
adjust for those. There is also the
issue of the potential delay in the diagnosis and how that's differential
between these women with prior exposure and those who are not. We've not been able to address that. But it seems to be creeping up in the idea
that these women with prior exposure
randomized to placebo have these strangely lower rates. I think that's the evidence for this that
there's a potential delay-in-diagnosis issue that is appearing in our data.
Our
more extensive modeling does suggest that prior combined hormone use has a
stronger effect than prior E alone use.
There seems to be an increasing risk of duration of prior exposure. The recency of exposure is an unclear
factor. That's because in our data it's
confounded with type of prior hormone use.
There is modest evidence for an interaction of E + P with prior use and
BMI.
As
I was indicating, the data are too sparse to jointly exam type, duration and
recency at least when I'm accounting for all of the confounders there. There is a difference in extent of disease by
randomization status but it's consistent across the prior use groups. We note that there is some hints of
differential effect by prior use, not on E + P but on the disease itself. The data on the post intervention comparisons
are still quite limited suggesting maybe in the last 12 months that the hazard
ratio has reduced a little bit but cumulatively we're still looking at
substantial increase very similar to our own initial findings.
I
want to briefly point out that we have also looked at the issue of abnormal
mammograms by prior hormone use.
Basically what we see is it's the current use here. So the solid line is no-prior-use and the
dotted lines are prior-use. Here's E + P
and here's placebo. We really can't
distinguish those with prior-use and not-prior-use. These aren't statistically significantly
different, but you can see the strong E + P effect that Dr. Chlebowski already
mentioned.
E
+ P increased the rates of abnormal mammograms.
This is slightly different than the way it was presented to you
before. Taking out the women who had
breast cancer, any kind, advanced or invasive, among those who never had breast
cancer during the study period, 32 percent of those had an abnormal mammogram
and 22 percent of the placebo women had an abnormal mammogram. Those are the false positive rates. The role of prior hormone use on mammography
performance is quite small. That's all I
have to say on this. I would now like to
introduce my colleague, Dr. Jane Cauley, who will be speaking about our trial
and fracture results.
DR.
CAULEY: Thank you very much. As was mentioned earlier, the fracture
results were published last week. I'm
just going to go through and summarize the results that were in the paper. The objective of the analysis was to present the
final results of the trial through the ending of the trial on July 7th. That adds an additional point four years of
follow-up. We also similar to the other
follow-up analysis wanted to test the hypothesis that the effective E + P
differs by risk factors for fractures, identify a subgroup of women perhaps who
are more likely to benefit from the exposure.
We measured BMD in a subgroup of women.
Finally we wanted to test whether the risk/benefit profile summarized in
a global index differs at women at higher versus lower risk of hip fracture.
All
the fracture outcomes in WHI include all fractures, including both traumatic
and non-traumatic fractures except for the fractures that are listed here,
fractures of the ribs, chest or sternum,
skull, face, fingers and toes and cervical vertebrae were in fact
excluded. All the fractures were
radiographically confirmed. Hip
fractures were centrally adjudicated and we had a 94 percent agreement between
central and local adjudication of hip fractures.
BMD
was measured at three of the clinical centers.
The three clinical centers were chosen to maximize the racial and ethnic
diversity in women who would have these measurements. We measured BMD at baseline, years one and
three as well as six although few of the women as yet had to have their year
six measurements. So our analysis are
restricted primarily to baseline, years one and three.
As
mentioned, the global index was formed a priori during the design phase of the
trial. This wasn't a post hoc definition
of global index. It included life
threatening conditions that were both primary and secondary endpoints of the
trial. Again the most important thing
here is that all of the analysis are intended to treat, but I just wanted to
point out that hip fractures we present the adjusted confidence intervals. For all the other fractures, we present the
nominal confidence intervals. Why the
difference? Well hip fractures were one
of eight clinical outcomes that were monitored by the DSMB. That the only fracture outcome that we
presented adjusted confidence intervals.
Now
I wanted to give a little background. We
tried to summarize a woman's risk factor for risk of fracture. There are various different scoring systems
that have been published. Most of them
have been used to identify women who may
have osteoporosis. That is they are used
to identify women who would benefit from having a bone density
measurement. There's really only one
fracture risk scoring system that's been published by Dennis Black from data
from osteoporoic fractures. We followed
his model and developed it within the WHI.
Initially
the first step is we took the various risk factors for fractures and looked at
the relative risk of the odds ratio of hip fracture in age-adjusted logistic
regression models. Based on those models
if the P-value is less than 0.10, they were entered into a multi-variate
analysis. Those variables that were
significant in the multi-variate analysis contributed to the calculation of the
summary score.
The
four risk factors in WHI that were significant in this multi-variate model and
contributed to the scoring system are shown here. So for age, the odds ratio was statistically
significant at 1.14 and a woman was assigned a zero to seven points for her
age. For instance, a woman age 50 to 52
was assigned zero points for her age.
Whereas a woman age 76 to 79 was assigned seven points for her age.
A
history of a prior fracture after age 55 again is significant odds ratio. It was assigned two points. Current smokers were assigned two points and
a low BMI was assigned one point.
Essentially for each individual woman these points were then summed and
we summed for the total fracture score for that individual woman. We then divided that into tertiles and looked
at the various risks hazard ratios across these tertiles of the summary
score. Now the area under the curve
("AUC") for the summary score of predicting hip fracture was 0.79
indicating moderate predictive strength of our summary score.
There
was no difference in the summary score by randomized groups. In this slide, we just combined the E + P and
the placebo group to give you just some descriptive characteristics of
women. Who were the women that we're
calling at high risk of fracture? As you
can see for age, the average age of women who were considered at low risk of
hip fracture was 56 compared to an average ago of 72 for women who were
considered at high risk of fracture.
BMI
went in the opposite direction as expected.
Women who were considered at high risk of hip fracture had an average
BMI of 27 compared to an average BMI of 30 in women at low osteoporosis low
risk of hip fracture. Percent of
Caucasian increases such that 90 percent of the women who were considered at
high risk were Caucasian compared to 77 percent of women at low risk of hip
fracture.
The
current smoking was three percent versus 16 percent. Current hormone therapy was 10 percent in the
low risk group compared to three percent in the high risk group. In terms of a personal fracture history since
age 55, it went from 24 percent in women who were considered at low risk of hip
fracture compared to 59 percent considered at high risk of fracture.
In
terms of the subgroup of 1,000 women that we had bone density measurements on,
we looked at the percent of women who had a T-score less than -2.5 using the
WHO ("World Health Organization") definition of osteoporosis. There were about 12 percent of women
considered at low risk who had a T-score less than -2.5 compared to 41 percent
in women who were considered at high risk.
In
terms of the overall prevalence of osteoporosis in the overall population, this
is looking at the WHO definition based on T-scores using T-scores at the
femoral neck. Overall the average
T-score in the hip was about -1.0 and in the spine it was about -1.3 and did
not differ by randomized group. So
overall about 10 percent of women in the E + P were considered osteoporosis
based on their T-score compared to 12 percent in the placebo group. This was not statistically significant. The majority of women, 53 percent, were
considered to have low bone mass and about one-third of the women had normal
bone density measurements.
Now
we'll get into the results. This shows
the data on total fractures. On the
right, there were 733 women who experienced a fracture in the E + P group which
corresponds to about nine percent of women.
There were 986 women who were randomized to placebo experienced a
fracture. That's about 11.1
percent. Overall the annualized incidence
of fracture was 1.5 percent in women on E + P versus 1.99 in women on placebo
corresponding to a 24 percent reduction in total fractures that reached nominal
statistical significance.
In
terms of hip fracture, there were 52 hip fractures in the E + P group compared
to 73 in the placebo. The overall
annualized incidence of hip fracture was 0.11 percent in the E + P group
compared to 0.16 percent in the placebo group.
The overall hazard ratio was 0.65 so a 35 percent reduction in the risk
of hip fracture associated with E + P.
In
terms of wrist or lower arm fractures, 189 wrist fractures compared to 245
wrist fractures. The annualized
incidence was 0.43 in women on randomized E + P compared to 0.59 in women on
placebo. The overall hazard ratio was 28
percent reduction in the risk of wrist and lower arm fractures in women
randomized to E + P.
Now
in WHI, we were limited to clinical vertebral fractures. There were 41 women who experienced a
clinical vertebral fracture. That is a
vertebral fracture that comes to medical attention. In many osteoporosis trials, they are used to
looking at that data. They traditionally
have used a morphometric vertebral fractures which are identified through
serial radiographs. We did not have
serial radiographs in the WHI. These are
the clinical vertebral fractures that come to clinical attention because of
pain. Overall, 0.09 annualized incident
rate in E + P compared to 0.15 in the placebo group. Overall the hazard ratio was 0.66
corresponding to a significant reduction in clinical vertebral fractures.
Now
we looked at various subgroups to see if the effect was different in these
various subgroups. On this graph, we
show the effect now because we're looking at five year age groups. This analysis is limited to total fractures
because the number other individual site specific fractures would have been too
low to look at five year age groups.
There
was a previous meta-analysis that was published a couple of years ago that
concluded that E + P or E products may prevent fractures in younger post
menopausal women but not in older post menopausal women. That analysis was based primarily on the
conclusion of one study in the younger women and one study in the older women. It's the HERS study actually. So we wanted to look to see in WHI do we see
a difference by age of the E + P on total fractures.
Again,
the yellow dotted line is the overall hazard ratio that we observed in the
overall group. The green circles here
corresponds to the point estimates for each of these five-year age groups along
with their 95 percent confidence intervals.
The P-value for the interaction term is here. There was no evidence that the effect of E +
P on fracture differed across age groups.
We
also looked at various other subgroups, years since menopause, by race,
ethnicity. That was limited to the total
fractures and BMD was also limited to the total fractures. All the other subgroups we looked at hip as
well as wrist and clinical vertebral fractures.
It didn't matter even though we looked at a number of subgroups. Dr. Anderson mentioned that we need to report
the number of subgroups that we look at.
If we looked at over 100, just five alone could be statistically
significant by chance alone.
Nevertheless in our analysis, none of the interactions were
statistically significant.
The
summary score data is shown here. If you
focus first just on the placebo group, the annualized incidence of fractures in
the placebo group in yellow was 1.33 in
women who were considered at low risk of fracture and it increased to 2.74
about a doubling of the rate of fractures in women considered at high
risk. But nevertheless whether a woman
was low, moderate or high risk of hip fracture, you can see that there was no
significant interaction between the summary fracture risk score and the effect
of E + P in reducing fractures.
Therefore the E + P reduced fractures equally well in women who were
considered at low risk of fracture as to women who were considered at high risk
of fracture.
This
just puts the WHI results in relationship of the data that were published in
the Osteoporosis Research Advisory Group ("ORAG") that performed
several analyses summarizing osteoporosis treatments. The pooled estimate from this meta-analysis
that was published in 2002 was 0.87 with the upper confidence interval that
went up to 0.08. You can see the WHI
results are consistent with these previous studies and clearly show us a very
strong definitive result with respect to reducing fractures.
What
about the BMD results? These are the
lumbar spine. We measured at the lumbar
spine the hip as well as the whole body.
We found consistently higher BMD measurements in women randomized to the
E + P so that by the end after three years of treatment, the lumbar spine
increased over 6.5 percent in the E + P group compared to about 1.2 percent in
the placebo group which is overall a 4.5 difference in BMD at year three at the
lumbar spine with somewhat smaller differences at the total hip which is
consistent with other osteoporosis therapy showing larger effects on lumbar
spine than on the total hip.
Now
we turn to the last goal which is try to identify a subgroup of women who are
sufficiently at high risk of fracture that indeed the risk/benefit ratio may
switch to us seeing more benefits. This
is our summary score again. If you focus
on the placebo group, we know that the high fracture risk women were much
older. That explains somewhat why we see
that most of these global index events are obviously more common in older
women. But nevertheless the actual
overall event rates are much greater in women considered at high risk of
fracture compared to women at low risk of fracture.
Nevertheless
the interaction term was not statistically significant. So the hazard ratio went from 1.2 in women at
low risk of fracture, 1.23 in women at moderate risk of fracture and 1.03 in
women considered at high risk of fracture.
But the overall interaction term was 0.54. So essentially if you focus on this specific
point estimate, the hazard ratio, it's essentially neutral. We did not identify a net benefit in those
women.
The
limitations of our analysis have been pointed out by several of the other WHI
speakers. We studied one E + P regiment. Our fracture risk score, the ratio of highest
to the lowest risk was modest at about a twofold difference in fracture rates
between women considered low versus high.
We could not incorporate BMD measurements into our fracture risk score
because we didn't have them measured on all of the women.
We
also don't have any information on whether or not the women had a prevalent
vertebral fractures and it's well known that low BMD and prevalent vertebral
fractures are two of the strongest risk factors for hip fracture. It's possible, therefore, that the benefit
versus risk profile could differ in women who had severe osteoporosis but we
were unable or limited in our ability to identify women who had severe
osteoporosis. Again we were limited to
clinical vertebral fractures. I added
the global index here as a limitation but it's not really a limitation because
it was designed a priori and it included life-threatening events that were
basically primary and secondary endpoints of the trial. However it did not include vertebral
fractures which are one of the most common osteoporoic fractures.
So
in summary E + P increases BMD and reduces the risk of fracture in healthy
predominantly non-osteoporoic women. The
decreased risk of fracture was present in all subgroups of women examined. The effect of E + P on fracture is consistent
with recent meta-analyses. Finally, the
effect of E + P on the global index did not differ across tertiles of fracture
risk. There was no evidence of a net
benefit in women at high risk of hip fracture.
So
the conclusion. Given the overall
unfavorable risk/benefit ratio, the overall global index indicating more risk
events than benefit events in the total population as well as the availability
of other agents for the prevention and treatment of osteoporosis, we believe that
estrogen plus progestin cannot be
recommended for the prevention or the treatment of osteoporosis in asymptomatic
women. Before the combination of
estrogen and progestin is considered for the purpose of fracture prevention,
women should be fully informed about the potential adverse effects. Thank you very much. Now I'm going to turn the podium back over to
Dr. Anderson who is going to address some additional questions that were posed
by the Panel.
DR.
ANDERSON: Okay. Following up with a few additional subgroup
analyses, I was asked to look at fracture rates by prior hormone use. For this, I chose to use total fractures
because in subgroup analyses you start running out of sample size pretty
quickly. Total fractures obviously have
the greatest numbers and the fracture data tend to line up so beautifully
across the fracture site. I thought this was a reasonable way to do it.
You
can see the overall results of a 24 percent reduction consistent in both women
who are not exposed to hormones before the trial and those who took hormones at
some point in the past. I didn't do a
test for the interaction here, but I can guarantee you that it's not
statistically significant.
These
are the curves. They also imply no
statistically significant interactions.
We did this sensitivity analysis, the per protocol thing, where when a
woman became non-adherent to her study medications we stopped counting events
that happened more than six months later.
That actually for fractures never changed the results very much which
suggests to me a certain amount of carry-over effect. The benefit doesn't stop rapidly.
Then
probably more interesting is the interaction between prior hormone use and
BMI. What I basically see is the same
pattern. So low BMI, high BMI here in
the no-prior users and the same in the prior users. It's just really the same pattern. The P-value for the interaction is 0.71. So being obese of course protects a little
bit. Having prior hormone exposure
protects a little bit. The interaction with
E + P says that E + P is protective in all of those groups.
Those
are the four curves associated with that.
You can see a slightly stronger difference in BMI it looks like. I have the scale wrong so you can't make the
comparison there easily. Again
unweighted P-value for the interaction is not statistically significant. I didn't do the weighted P-values because
again for osteoporosis the difference between weighted and unweighted is
negligible.
Several
comments about the global index. I
wanted to spend a little bit of time about that. This is the updated global index which is new
data. It has not been published. This is data through July 7th of
last year with updated endpoints, an increase of 12 percent of E + P over
placebo. This is showing it by age
group. It's bouncing around a little
bit, but the P-value for interactions saying are these statistically different
is 0.99. Truly this is the best summary
when you are looking at it by age.
This
is looking at it by BMI. Women with a
BMI less than 25, their hazard ratio for the global index was 1.16. 1.12 for 25 to 29 and 1.08 for over 30. The P-value for interaction is 0.62. So you might think that there's a suggestion
of a trend here. I didn't do it as a
trend statistic. It could be that the
leaner women are slightly more at risk for one of these events. But based on this test, we don't have much
evidence of that.
By
some of the other fracture risk endpoints, as calculated, the P-values also
suggest that the summary of the global index statistic is a valid estimate for
all those subgroups.
This
is the increment of data since the intervention stopped. Again this is new data so these are new
events, 13 versus 17 hip fractures. So
you are seeing that protection is continuing in essentially the 15 months since
the trial ended. Vertebral fractures
still benefit, all the fractures.
Interestingly the global index also for the incremental events since the
trial stopped remains elevated and it is highly statistically significant. You know the nominal Z-value, the 0.5 level
test, is 1.96 or two standard deviations so this unweighted Z of -3.16 is
highly statistically significant.
This
is the cumulative results. Those
incremental data don't change our picture of benefit for fractures very much at
all. These are all pointing in the same
way they did a year ago. The statistical
evidence is strong for that prevention.
But so is our evidence that the overall harm is greater than the benefit
with a 14 percent increase in the number of women who had one or more of those
events. These are not counts of events
but counts of women who had one of them.
It's highly statistically significant.
I
don't have a summary slide. Sorry. But I wanted to make a comment about
this. When the global index was defined,
it really was for the purpose of monitoring the trial because we knew we'd have
risks and benefits. It was a tool to be
used, but it had become more than
that. We didn't really envision it
playing such a role in understanding how these drugs might be used. But I think it brings to bear on the issue
that prevention work is really quite difficult to do.
We
didn't anticipate that the trial was going to come out this way at all. It was going to be much simpler. All we had to do was worry about whether the
breast cancer was going to show up in time for us to see it. So this global index is pristine in the sense
that it was developed before we saw the data and it was based on diseases that
we thought might be impacted by these interventions and that had a significant
effect on the mortality of older women.
Now
there's been some suggestion that it's not inclusive enough. We would certainly acknowledge that it
doesn't include all the potential impacts of these medicines. It was never envisioned to. This was a prevention trial for chronic
diseases. We captured the critical
chronic diseases that we were looking at.
We acknowledge some of the effects.
I
think we need to be very cautious in the idea of expanding this global index by
cherrypicking particular endpoints that we like. That's a great way to engineer something to
come out the way you want it to do. But
because it's been mentioned several times, I will note that the difference in
vertebral fractures right here will not cancel out. If you start out in these benefits, you need
to go ask for a vertebral fracture if that's a benefit. Define the criteria by which vertebral
fractures make it into a new global index and then let's start applying it to
other diseases and make sure that we have captured all the risks and benefits
that satisfy those criteria before we calculate it. So I think with that I will end and turn it
back to my colleague, Dr. Jacques Rossouw.
DR.
ROSSOUW: And don't worry, I'm not going
to give my talk over again. I just
wanted to summarize where WHI is going from here. Dr. Stefanick has mentioned some of the
publications that are coming out in the next few months, but one that the
investigators as a group feels is important is to summarize, to put everything
together, all the major findings and some of the most important subgroup
analyses some of which you saw today in a final comprehensive paper much like
the paper last year in JAMA, but with the updated information and the
informative subgroup analyses. That
obviously has to wait until all of the other papers on specific disease
entities have been published. That is
something that we envision doing perhaps next year.
The
other detailed analysis that Dr. Anderson showed you some preliminary work on
is also one I think that will be of interesting to the community. That is on breast cancer, specifically by
prior use. Now as she's shown you some
of the preliminary work-up of that, we haven't yet found an explanation as to
why in the trial there was an apparently lesser increase in breast cancer on E
+ P in the women without prior use. But
she also showed you that those women appeared to have baseline if you look at
the placebo group to be of somewhat higher risk. So you have something strange going on here.
Then
if you look at the Kaplan-Meier curves and then the year-by-year data that Dr.
Chlebowski showed you, then you also get the impression that those without
prior use there's something strange going on in the first three years. Why is the hazard ratio lower in the E + P
group than in the placebo group in the first three years? Is that a real effect? Do you have a bimodal effect where the E + P
in those without prior use initially has a dampening effect on breast cancer
and then later there's an increase? I
don't know what the biological explanation for that would be. Or is it an artifact that we need to try to
tease out and explain why we could not ascertain breast cancer early on in
those without prior use? Those are two
important publications that are coming down the pipe.
Now
as my colleagues have said, the trial of Premarin alone, E alone,
continues. The plan termination is
2005. Of course, it undergoes review
every six months with updated data and further analyses. But the plan termination is 2005. So that tells you that the results do have
some differences compared to the E + P trial.
Now
in trying to explain the findings that you've seen today, the investigators
have also completed and have launched a number of case-control laboratory
analyses for the cardiovascular outcomes.
These have By and large been completed for the major outcomes. So we're looking at whether baseline or one
year lipids, coagulation, inflammation markers, other biomarkers such as
homocysteine and allelic variations related to those intermediate factors
whether they influence the E + P effect in the trial. Some of those have been published in the
publications that have come out over the last year, but there are others, in
particular, the genomic investigations that will be published in the future.
For
fractures, there is an interest in the group in looking at whether baseline
estradiol and sex hormone binding globulin ("SHBG") and markers of
bone turnover and allelic variations related to estrogen metabolism influence
the results. Are the results different
in subsets of the population more or less benefit and similarly for breast
cancer again where the baseline estradiol and also testosterone SHBG and
allelic variations related to hormone metabolism influenced the results or some
of the more important lab investigations that are in the works?
Now
for the E + P trial, we plan to continue surveillance. You saw a little bit of that data of all
clinical outcomes until 2007, in other words, five years post trial
follow-up. This is geared particularly
to following whether the increase in breast cancer risk persists and if so for
how long.
Now
the E alone trial the investigators don't know the results but the Institute
has agreed to fund post-trial surveillance for two years following that
study. It's basically predicated upon
what we were observed in E + P. There
are going to be some effects in the E alone - I don't know which - that are
going to be worth following up to see whether they persist or not. They are unspecified at this point. We don't know what they will be.
Then
most exciting is that the Institute has also agreed to fund a larger enterprise
to ensure that the enormous amount of data and the extraordinarily valuable
biological specimen repository is exploited fully to the benefit of the entire
scientific community and of the population.
We have a cohort of over 160,000 participants in the various trials and
observational studies. We have citrated
blood, EDTA plasma, serum, DNA in the form of buffy coat and in subset urine
samples that we've only barely utilized a small fraction of that.
The
principle here is to invite WHI and other investigators and entities including
commercial entities that in some places have the best expertises particularly
when you think of proteomics and genomics to exam this dataset and to
participate in the further scientific utilization of this resource. To that end, the Institute will issue a Broad
Agency Announcement towards the end of 2005 with funding for 2006 to 2010 to
invite the entire community to address the scientific questions that this
resource can be useful for. There is
some funding set aside for the Broad Agency Announcement but as part of this
activity it will made clear that other sources of funding from inside NIH and
outside NIH can also be applied to this resource. Now the exact structure of this and so forth
has to be worked out but I thought it was important to tell all of you here
that we all need to start thinking about what we can learn from WHI aside from
what has been revealed so far. Thank you
very much.
CHAIRMAN
McCLUNG: I thank all of you for a very
careful and thoughtful presentation to us that has I'm sure given us all kinds
of thoughts of queries and questions to ask.
We're a little behind schedule.
What I propose is that we still plan to have our lunch break from noon
until 1:00 p.m. We have ten minutes for
some questions that we can address to the WHI panel at the moment. Then we'll have time if we need to reopen that discussion when we come back
from lunch. So are there questions that
the Committee members have to direct to Dr. Rossouw and to his colleagues?
DR.
CARPENTER: I was taken by the protective
effect of BMI in several of the parameters that you presented. I was wondering if this could simply
represent something like a dosage exposure effect or if it's even possible to
look at this data with respect to dose on a per unit weight basis or something
that would allow us to tell whether there's some critical exposure level that
would protect you from some of the consequences.
DR.
ROSSOUW: So the question is whether we
can do further analyses to see whether BMI modulates the effect. I guess it gets also to the issue of what the
endogenous levels are to start off with and what the response is to the
treatment. It's possible, for example,
that women with a higher BMI start with higher estrogen levels but also have a
less of an increment in on-treatment levels.
We plan to get at some of this by looking at the baseline levels. It may also be interesting to look at the
on-treatment levels in the mode and see whether that influences it. Does that
answer your question or were you getting at something a little different?
DR.
CARPENTER: No, I was just very simply
trying to think of mechanisms by which that could happen.
DR.
ROSSOUW: Right.
DR.
STEFANICK: I'd just like to comment that
when you say "protective effective BMI" I'm hoping you're only
talking about bone and not breast because an important thing with the breast is
to realize that we're comparing two groups so it may not really be protective
as much as the fact that the placebo group is at a high enough risk that adding
that little bit doesn't make a difference.
It's like a dilution effect and I don't know if that's an appropriate
thing to say. Rowan could comment on
that. People have said that on other
data that this BMI seems to be protecting women against the breast cancer. It's really the case that their overall risk
is higher so adding one more little risk like E + P doesn't make that big of a
difference but that's my perspective.
DR.
CHLEBOWSKI: As Garn points out, all
these subgroups are really very tricky.
One of the other things that we did not have time to present was we
looked at the Gail model which is another way of looking at the tertiles of
Gail model risk for five years of risk.
The women who were at the absolute lowest risk again wasn't significant
interaction but they had suggestion of a higher effect on breast cancer than
people who had the highest risk which is a little counter intuitive to the way
we think about it and that could integrate some of these things like body mass
index.
So
it gets back to the same question of "Are these factors such as obesity
that give you a high level means that adding something on top of it doesn't
matter". So the concept that we can
find the low risk group is very hazardous because if anything there seems to be
in some of the lower risk groups at least for breast cancer, a suggestion that
maybe E + P is a little higher relative risk, not absolute risk.
CHAIRMAN
McCLUNG: And that underscores the
problem in mixing or confusing absolute and relative risk. When you are taking risk defined on absolute
by either the Gail model or the Black model and then looking at relative risks
among groups based on absolute risk, you
have to be really careful about our terminology and about how we interpret and
conclude from those sorts of things.
Other questions? Yes.
DR.
STADEL: This is a technical question. On statistical analysis, you had outcome
analyses that were both weighted and unweighted depending on people's beliefs
about the nature of the disease. Were
any of the interaction tests weighted based in particular on rather a known
relationship of adiposity to endogenous estrogen production which could lead to
a weighting of expectation with regard to the relationship of body mass to
outcome? I just wondered if there was
any parallel weighting of interactions
testing as was done with outcome testing.
DR.
ANDERSON: Yes. For the interaction test, I mostly showed you
both weighted and unweighted, but I have to say that in developing the protocol
and all that, we never talked about how we would do interaction tests. It's not clear to me whether the weighting
that we defined for the primary endpoint comparisons is the right weight to use
for interactions. I put them there out
of intellectual honesty but it's not clear which is the right way to go.
DR.
FOLLMAN: I had a comment for Dr.
Stefanick. One thing that you looked at
was the hazard ratio for the CHD over time.
You showed that early on there seemed to be a harmful effect of E + P
and later on it reversed. Your explanation
for that was basically the patients and the women in the E + P group had
already developed their breast cancer so it wasn't a fair comparison between
the two groups at that point in time.
But I was wondering if people had also looked at an alternative
explanation where maybe the benefit of E + P takes a long time to manifest
itself. I was wondering if this might
explain or relate to the epidemiological literature where you did see an
beneficial effect of E + P on CVD thinking that in the epidemiologic studies
women in those studies would have been followed up and would have a fair amount
of prior hormone therapy as they enrolled.
DR.
STEFANICK: Okay. Just to clarify, you said breast cancer but
you meant CHD.
DR.
FOLLMAN: Right.
DR.
STEFANICK: Right. Well, the alternative hypothesis is actually
the one that we tested in a HERS follow-up study because people had that same
idea that there's this early harm and later benefit which they were attributing
to the one-year lipid changes. We've
never actually seen the four year lipid changes from either study.
But
in terms of to follow up on that question, we're actually doing some very
interesting analyses now within WHI on the observational study in which we have
93,000 women, many of whom are hormone users and the clinical trial. We're trying to tease that apart. Obviously I'm not going to say anything about
what we're finding in that. The length
of use is an important issue. When you look at observational studies, many
of the studies are looking at women who are current users and then they do a
survey two years later.
So
you have a very strange mixture of who is actually a user/non-user in the
observational studies. I'm not really
sure that we want to completely go back to the idea that there is still benefit
because we see what I call the "survivor" group at the end. I'm actually going to ask Garnet to comment
on this as well.
DR.
ANDERSON: Yes. I want to sound a real note of caution for
those year-by-year analyses. The first
year comparison is a randomized comparison because everyone who is randomized
goes through that first year and has an event and is counted. The second year becomes a woman who didn't
have an event in the first year. That
becomes the denominator. So there are
survivor issues. The farther out you go
on that timeline the worse it is.
In
addition, we have lack of adherence that starts to feed into that in a big way
and later on. So looking at
"randomized comparisons" in those later years in a year-by-year
fashion is dangerous territory and I wouldn't want to make much inference about
that year six data.
DR.
ROSSOUW: Let me go back to the slide
that prompted Dr. Follman's remark. So
what Garnet was saying is that this is real result. It's actually quite a strong result, but we
have to be cautious about the results after these subsequent years. Nevertheless it's interesting if you look at
the rates in the E + P group over time.
There's this increase here but there's no convincing evidence that it
decreases over time. What's happening
here, who knows? But it is striking that
it's the year in which the placebo group is highest. That explains this apparent risk reduction
there. This is very messy data.
I
did want to point out that the observational data on this issue are very messy
too. It turns out that the observational
studies are most of the early events so their estimate of what happens in the
first year or so after studying hormones is very poor. But nonetheless if you look at the
conventional analyses of observational data particularly the Nurses' Health
Study, it suggests that the benefit is greater in the first few years and less
in later years. So I don't think there's
convincing evidence from the observational studies to suggest that longer
duration is better. If anything, it may
be the other way around.
DR.
CHLEBOWSKI: Just another comment. When we're talking about duration effects and
getting back to breast cancer for a second, just reminded me to really make
this point again. If when we talk about
the time-to-events for the breast cancer, it just reminded me that the
mammograms were 74 percent more likely to be abnormal after one year, but in
that first year, there was about 30 to 40 percent less cancer seen. So we ended up having almost twice as many
abnormal mammograms, a significantly fewer cancers seen and more advanced
cancers subsequently being delivered.
Those things taken together just looking at those numbers suggest that
cancers are growing during those initial years but we're not able to see them
with mammograms which are mush less effective in finding the cancers. If we're looking at those first two or three
years, we really don't know what we're seeing because it appears that the E + P
is making the mammographic diagnosis of those cancers much more difficult. That's why they're being seen later. So it's the same kind of question of how can
we look at fairly those first two year events when we know that there's two
other things that are occurring in the background.
DR.
CAULEY: I just wanted to emphasize also
something that Marcia said when she showed the Kaplan-Meier of the global
index. At no point was the E + P curve
lower showing more benefit than the placebo group. That's during the entire duration of the
follow-up.
CHAIRMAN
McCLUNG: All right. Now that we're warmed up with that discussion
and know what the situation is going to be, let me propose that we now break for lunch. That will give all of us a chance to reflect
on what we've heard and gather our questions.
Let me encourage the panel members to refrain from working on this over
lunch either with each other or with others from outside our group so that
we'll all come back fresh and new at 1:00 p.m.
Thanks. Off the record.
(Whereupon, at 12:02
p.m., the above-entitled matter recessed to reconvene at 1:06 p.m. the same
day.)
A-F-T-E-R-N-O-O-N
S-E-S-S-I-O-N
1:06
p.m.
CHAIRMAN
McCLUNG: On the record. Okay.
Let's follow up with questions and clarifications of the panel to the
WHI investigators. So we'll devote 15
minutes to that and then if we need more time, we can do that later in the
afternoon. Dr. Lukert, I know had a
question.
DR.
LUKERT: You know, there's accumulating
evidence that there's a connection between vascular disease and osteoporosis,
that people with osteoporosis tend to have a higher incidence of
atherosclerotic change. What I was
wondering is, if there's a preponderance of the people who have cardiovascular
events who also were at high risk for osteoporosis. Because that would make some difference, if
one of the really high risk populations were the people who had a greater
tendency toward osteoporosis, you'd be more hesitant to intervene with that
particular form of treatment in that group of patients.
CHAIRMAN
McCLUNG: So the question is, can they
identify or did they look at ?-
DR.
LUKERT: Yes.
CHAIRMAN
McCLUNG: ?- individuals based on cardiovascular
risk ?-
DR.
LUKERT: At risk for a fracture.
CHAIRMAN
McCLUNG: Because they stratified on the
risk of fracture and looked at it the other way around.
DR.
LUKERT: Right.
CHAIRMAN
McCLUNG: So you are looking at the
opposite way. Dr. McCauley.
DR.
CAULEY: No, we didn't really look at
that. It's an excellent question. The only thing that I would point out is that
the fracture risk score was based on prediction of hip fracture. So the high risk group they were much older
than the low risk group. Just by their
age alone, they are going to be a greater risk of CVD.
DR.
LUKERT: It would be interesting however
to look at that age stratified way also if you can.
DR.
CAULEY: Yes, even the factors, age. Smoking was also greater in the high risk
group, but BMI went the opposite way. So
some of the risk factors of CVD would be consistent with an increase of
cardiovascular risk in the high fracture risk group and some not.
CHAIRMAN
McCLUNG: Dr. Bone, you had a question.
DR.
BONE: Yes, we've had a very nice
presentation of a lot of analyses and subanalyses and subanalyses. One of the points that was made is that
rather than look at the individual groups in some cases, there was a test for
whether there was an interaction. We saw
P-values of about 0.1 in many cases that were displayed. When we talk about a hazard ratio of 1.2
versus a hazard ratio of 1.0, was there actually testing of the power of this
test of the interaction term to detect a true difference?
DR.
ANDERSON: No.
DR.
BONE: So that wasn't tested. Thank you.
CHAIRMAN
McCLUNG: Dr. Woolf.
DR.
WOOLF: Several members of the public
this morning indicated they were concerned about the potential for
discontinuing Prempro or conjugated estrogens anyway for peri-menopausal women
because of the symptomatology. I thought
I saw a slide briefly flashed by me that seemed to indicate that the global
index was equally poor for women in the lowest age group as with any. Is that a true assessment?
DR.
ANDERSON: Yes. I showed you global index by five year age
categories and the P-value for interaction of that was 0.99 saying that we
really have no statistical evidence for a difference by age.
DR.
WOOLF: Can I follow up on Dr. Bone's
question? Does a failure to do a power
analysis say anything about the validity of the interaction's statistics?
DR.
ANDERSON: A power analysis asks
"What's the probability of finding an effect if there is a true one of a
certain size?" So in an interaction
test, it's rather challenging to ask what the power is for something like
that. We have to acknowledge that there
are few women when you cut up the data so finely. To address that, we tended to do those
interactions with a continuous variable instead of dicing it up into little
cells. We just did it continuously and
still didn't find anything. Yes, we
don't have great power in some of these.
I would not want to hazard a guess of what the power would be, but this is
the best data that we're going to have on that.
These data pretty much stand for themselves.
DR.
FOLLMAN: Just a comment on the power
analysis issue, Dr. Anderson's exactly right.
We don't have good power for these tests of interaction. That's just the way clinical trials are
designed in a way. You design it to ask
the main question and by definition, you essentially don't have good power for
the interaction. So they give you some
comfort if there is not interaction, but it's understood that there's not a lot
of power for it. They did a lot of tests
and they did some correction for the multiple tests.
I'd
like to amplify on a point that Barbara made.
One interesting analyses that I thought laid everything out on the line
was the global index analysis particularly when you looked by tertiles of
fracture risk. But then on reflection,
you realize that for this Committee we're really just interested in the women
who would be getting this probably as a second line therapy for
osteoporosis. So it would be interesting
to look at the global index as a function of tertile risk amongst those women
who would be less likely to receive hormone replacement therapy for that
indication. So, for example, eliminate
those who had hypertension at baseline or who had high risk for breast cancer
or had dyslipidemia, maybe had prior breast cancers and so on and rerun the
analysis. I was wondering if you've had
thought about that or had done that kind of sensitivity analysis for the global
risk index as a function of tertiles of fracture risk.
DR.
CAULEY: No, we have not done that
analysis. All those risk factors that
you've mentioned, the dyslipidemia the prevalence was rather low. Hypertension about one-third of the women did
report hypertension. For all the other
risk factors, the prevalence was rather low.
DR.
CHLEBOWSKI: And with respect to the
breast cancer, the women self-selected against that anyway. When we looked at the Gail risk score for the
group, it was 1.5 for a 62 year old population.
That's less than a 60 year old with no risk factors which is 1.7 percent
five year risk. Women have to be neutral
to the question and there was enough noise about breast cancer risks that those
women who were higher or had more family histories just didn't enter the study.
DR.
ROSSOUW: Let me just briefly respond to
that. Dr. Anderson was right and you
were right that you power this to look at the overall effect and if you do
these subgroup analyses and the interaction tests and you don't find anything
strikingly different, then you tend to believe the overall result is the one
that probably applies to the subgroups as well because that is the robust
result that you have. In terms of
looking at clinically relevant subgroups beyond those that we've done, if
someone could tell us who are the patients that are going to get this treatment
for osteoporosis prevention and what are their characteristics, we could try to
run such an analysis.
But
I'm not sure for example that a person who has a modestly elevated blood
pressure wouldn't still be a candidate for osteoporosis prevention for
example. But if you could give us who
are the people. Is this a targeted
population? My impression in the past
has been the answer is "No."
Basically the gestalt was that every post menopausal woman should
basically get this if she had a low BMD.
Right? If there is a different
kind of gestalt emerging now, then we could potentially run some analyses
although again our palate will be pretty low to get informative results.
CHAIRMAN
McCLUNG: Dr. Bone.
DR.
BONE: Thanks. A couple of comments related to the recent
discussion of Dr. Follman's question in particular and it ties into subsequent
comments. The investigators did what
they could with what they had as far as this risk estimate. But I think they demonstrated pretty clearly
that there was some real limitations to the ability of the information
available to them to classify the patients according to their risk of either
developing an osteoporoic fracture or even developing osteoporosis as we know
to be defined by bone densitometry because they didn't have at their disposal
the basic tools that we use for doing those things.
So
a fair number of patients classified as low risk actually qualified on their
basis of their bone density as having osteoporosis amongst those whom bone
density were measured. We would
ordinarily expect if we were going to identify a high risk group to see a much
higher relative risk, say a log higher, who have a tenfold relative risk or
something like that. So some of the
questions that may not be possible to model but I don't know if they would be
impossible to model would be to look at what the risk/benefit ratio would be in
patients who actually had osteoporosis or try to imagine what would happen if
we had the conventional tools that we would use to assign risk.
The
understanding of what's meant by "prevention" of osteoporosis depends
a lot of where you are. At the time of
the U.S. guidelines were originally formulated, it just meant that your bone
density didn't go down. But I think the
clinical practice probably conforms a little more closely in some cases to what
the European regulatory authorities which is basically prevention of so-called
"osteopenia" progressing to osteoporosis based on bone density. They actually classify early remedial post
menopausal bone loss and a few years delayed which their delayed study would
correspond more closely to what was done here except ?-
Just
to take a minute. Up to five years post
menopausal with osteopenia, more than
five years with post menopausal to osteopenia are classified separately in the
European guidance. Somebody correct me
if I'm slightly off on that. It might be
three years. I think it's five. So most of the patients weren't immediately
post menopausal. They weren't classified
on the basis of having a somewhat low bone density. But that would be the group that probably is
more thought of as the prevention population by more doctors these days just to
respond to the other question that Dr. Woolf so raised.
DR.
WOOLF: Getting back to Dr. Rossouw's
point about who to model, I take the reverse and say "Who shouldn't be on
the drug" and that's clearly the women who are hypertensive and smoke. They have a far increased risk of
stroke. I think a physician who uses
estrogen in that setting does so at his parol and the limited malpractice
insurance. So you can exclude some of
those folks, certainly risk of stroke and someone with significant hypertension
and/or smokes. You should model them out
because they probably wouldn't be an ideal candidate for the drug anyway.
CHAIRMAN
McCLUNG: All right. Let me propose that we draw this section of
the discussion to a close and move on to the next part of the program. Representatives from Wyeth Pharmaceuticals
have prepared a presentation. Dr. Joseph
Camardo will lead off and coordinate that.
DR.
CAMARDO: Thank you very much. Good afternoon. On behalf of Wyeth, I want to thank the FDA
first of all for inviting us to the Advisory Committee Meeting and for the
Committee giving us the time. Our
presentation today will focus on how we support the appropriate use of hormone
therapy based on the evidence available.
That's evidence about the risks and the benefits, evidence from clinical
studies and evidence from WHI as well.
My
objective today is not to review a lot of data.
I have some data but not a lot of data.
My objective is really to explain to you how the medical team at Wyeth
interprets the data from these studies, what data we emphasize and why although
we acknowledge certain risks we continue to support estrogen/progestin as an
option for osteoporosis. I also want to
explain how the company responds when we receive clinical study data particularly
safety data that will have an impact on the use of the product for women and
practitioners.
Now
I will be presenting positive data about Prempro. I want to say in advance that it's not my
intention to ignore or downplay the risks observed in WHI. You will see that we take these reports very
seriously. I will discuss them, but I
did choose to reduce some of the effective data first. I just wanted to remind you that I'm the head
of Clinical Research at Wyeth. I'm
representing actually a medical team that's been supporting our reaction to the
WHI and actually our support for estrogen/progestin over the last several
years.
I
have four items I would like to cover today briefly. First there's an introduction. I want to explain how we come to the
conclusions that E + P, the combination Prempro, should be used for
osteoporosis. I also want to go over
some clinical data about bone loss and estrogen therapy. This probably shouldn't be new to any of you
but I did want to review it today. I
also want to discuss the WHI data and it's clinical application to practice and
the risk that were reserved in this trial and how we deal with them. The fourth thing is that I want to review the
information in the current product label.
What I mean by that is the product-prescribing information and that was
I believe included in the material that was sent to the Advisory Committee.
Let
me start with this one slide. These are
five points that the medical team at Wyeth used to construct our
recommendations about Prempro. These are
really the five ideas that I want to convey to you today.
1.
The first is that prevention of osteoporosis is an important aspect of
healthcare especially for women in menopause.
I think we would all agree to that.
2. The second is that Prempro is effective for
osteoporosis and it is one of a relatively small number of medical therapies
available for osteoporosis.
3. The third point, estrogen/progestin is the
only therapy that can reduce menopausal symptoms and prevent osteoporosis. I think we would agree with that too.
4. The fourth point is very important to us and
I want to make sure that it's emphasized properly. Practitioners really do need to determine the
use of hormone therapy for an individual based on all the evidence available
and the goal of treatment. I think that
should be clear from this morning's discussion and some of the questions that
came up in the afternoon because there are areas about which the certainty is
lacking.
5. And the final thing - and this is very
important from the company's point of view as the sponsor of the product - is
the Prempro label provides accurate information. The point is the point number four -
practitioners need to make the decision- has to be supported by point number
five which is that sponsor provides appropriate information.
Now
let's go into these in a little bit of detail.
I think we didn't talk about this very much today but there can be
significant disability and mortality related to fractures in women. It really does demand our attention. That's why we're having a meeting today.
An
interesting statistic, the National Osteoporosis Foundation advertises that
every 20 seconds there's a fracture related to osteoporosis. Also I think we know this that at any given
level of trauma someone with bone loss, whatever degree, is at high risk for
fracture than someone without a decrease in bone density or quality. So prevention of bone loss is an important
aspect of healthcare for women.
Let
me summarize just the four points in this slide.
1. First, we know bone loss accompanies
menopause.
2. We know that bone loss increases the risk of
hip, vertebral and other fractures.
3. We know that fracture risk increases before
bone loss has progressed to the level of osteoporosis.
4. We know that hip and vertebral fractures are
associated with increased mortality and also significant disability. This was alluded to earlier in the
morning. One year mortality after hip
fracture can be as high as 20 percent.
Twenty-five percent of women need nursing home care after hip
fracture. Vertebral and other
osteoporoic fractures can be disabling.
Now
I said I would talk about the positive data for Prempro. Prempro is effective for osteoporosis
prevention and treatment of menopausal symptoms. Remember this is one of the premises that the
medical team at Wyeth has based our discussion and our recommendations
upon. Prempro has been shown to reduce
non-vertebral fractures especially hip fractures now even in women who do not
yet have osteoporosis. You heard that
this morning from WHI.
You'll
also see some data from me about low dose Prempro which reduces menopausal
symptoms and also increases bone density.
I want to emphasize this is important because symptoms and bone loss may
be concurrent medical problems. We're
not really focused on symptoms today but I don't want to forget about them
because that is part of the clinical presentation in some women who also have
bone loss.
We
also all know that because the awareness of osteoporosis has increased, this
has encouraged the development of new medical therapy so that in 2003
estrogen/progestin is one of a number of agents available to protect bone
health. My point here is that the
availability of different therapies is an advantage. The therapies have different mechanisms. They had different side effects. This allows the women and the practitioners a
reasonable array of choices because each agent has strengths and weaknesses,
effectiveness, tolerability, compliance with each therapy. They may vary with individuals. I want to emphasize this because the medical
team concluded after looking our product and looking at the other products that
the option to use estrogen/progestin is an advantage of women and
practitioners, but it's not the only therapy available.
Let
me show you something about how we think about the strengths and
weaknesses. First of bisphosphonates, we
know that bisphosphonates prevent fractures.
There are clinical trials supporting that. But we also know that bisphosphonates may not
be suitable for all women. There are
limited data in non-osteoporoic women and bisphosphonates have gastro-intestinal
side effects.
The
selective estrogens prevent vertebral fractures, raloxifene, for example. But so far, raloxifene hasn't been shown to
prevent hip fracture. Moreover, hot
flashes occur in about 20 percent of women so it's not really an appropriate
therapy for women with menopausal symptoms.
The
fourth point here we talk about E + P today.
We know it prevents vertebral and non-vertebral fractures. We've also learned that E + P may be
associated with increased risk of breast cancer and CVD in certain
populations. The summary is the products
have strengths and weaknesses and the variety of agents available helps to
support clinical practice.
Now
we also concluded - and this was the fourth point on my first slide - that the
decision to use estrogen/progestin or not to use estrogen/progestin really
needs to be made by the woman along with a knowledgeable practitioner. Now it's very clear to everybody that the
results of the WHI study have had a major impact on the assessment of the
risk/benefit for estrogen/progestin. But
still a decision to use estrogen/progestin for osteoporosis and menopause and
particularly in the younger women cannot be based just on the WHI study.
The
overall objective of the study was not necessarily to target a therapy for
every woman who may use E + P. I just
remind you women with significant symptoms were discouraged from participation
in the WHI study. There were some women
in the study with symptoms but that was not a major objective of the
study. The study was designed to assess
potential benefits of long term use. We
went through those, fractures, colon cancer, CVD. We know the outcome and selected long term
risks, breast cancer, DVT. We know the
outcome there too. But it really wasn't
designed to assess a question that physicians do face all the time which is
"How to use estrogen/progestin in women closer to menopause who have bone
loss and menopausal symptoms."
Now
I intend to discuss the label for Prempro as the last item on the agenda. The premise here is that individual judgment
requires knowledge. The label for
Prempro represents again what the medical team concluded is the information to
support clinical decision making. The
key points about the label are shown here.
You've actually seen part of this earlier today. I'll discuss them briefly at the end of my
presentation, but there are four points here.
1. First the pertinent results from numerous
trials are included.
2. The safety information is updated regularly
after medical review of evidence.
3. The WHI data are included in the current
version of the label.
4. The information is available both to
practitioners and to women. There is a
product-prescribing information which is available to the prescriber. There's a patient package insert which the
women will receive when a prescription is filled. There's also the recent FDA
Educational Campaign which Dr. Orloff referred to in his introduction today.
Let
me go back to my first five premises. Prevention of osteoporosis is
important. Prempro is effective for
osteoporosis. It's one of a few agents
available. Hormone therapy, that's
estrogen/progestin for the purpose of today is the only therapy that can reduce
menopausal symptoms and prevent osteoporosis.
Fourth and fifth points very important.
Practitioners need to use the product, estrogen/progestin, for the
individual woman after making a decision based on evidence and based on the
goal of treatment. We need to support
their decision with the Prempro label providing accurate information.
I
want to talk now about the clinical data for E + P. There are four points here too.
1. Rapid and progressive bone loss that occurs
early in menopause can be prevented with E + P.
I want to show you some of that data.
2. Most fractures occur in women who are
osteopenic, not osteoporoic so early intervention may be important.
3. Prempro and I'll show this data at all doses
improves bone density in osteopenic women.
4. Prempro in the WHI reduced fractures
significantly even in women who were not osteoporoic.
Let
me review these four points in some detail.
First, this slide which I borrowed from Dr. Lindsay's Lancet article from
1976 shows that bone loss follows estrogen loss and it can be prevented with
early post menopausal use of estrogen.
The slide plots metacarpal bone mineral content on the Y-axis over time
on the X-axis for women who were not treated after ovariectomy which is the
blue line and women who were treated immediately after surgery, the red
squares, starting three years after surgery, the green and starting six years
after surgery, the blue triangles.
The
data from this study show that the women who started estrogen immediately after
ovariectomy preserved bone mineral content at or near their baseline before
ovariectomy. The women who started six
years later, the blue triangles, maintained bone mineral content at about the
same level it was when they started treatment but that was below their baseline
from their ovariectomy. Those who
started estrogen within three years actually fell in between the two extremes.
This
is a biological effect and it suggests that early post menopausal use of
estrogen would maintain higher bone strength.
It's one of the pieces of evidence that has supported estrogen use in
the early post menopausal period.
Other
evidence about the incidence and the number of fractures in a large cohort
study also suggests that early intervention would be useful. This slide from Dr. Siris' paper shows that
fracture incidence increases as bone density decreases. The density is only one of the factors that
accounts for risk. Bone quality which is
a reflection of remodeling is also very important but this does show that with
lower BMD score the number of fractures per 1,000 woman years in this cohort
increases several fold. It's actually
highest in the women with WHO defined osteoporosis which is to the far right of
the graph.
But
this slide shows that in the same cohort the actual number of fractures is
highest in the women with osteopenia because there are so many more women who
fall into the category of mild or moderate BMD loss who are not yet
osteoporoic. This is not too much
different from the population in WHI. So
this is not just a theoretical benefit which I showed you from the early
intervention. There appears to be a
practical benefit as well in that more fractures can be prevented.
Based
on the biologic effect of estrogen and the consideration that prevention of
further bone loss has a clinical benefit, we evaluated Prempro at different
doses specifically for osteoporosis prevention in post menopausal women, many
of whom were osteopenic. These studies
include the original studies of Prempro of more than ten years ago and the most
recent study performed as the basis for approval of the low doses of
Prempro. This recent study is the
Women's HOPE study. That's the one I'll
discuss briefly.
The
study was designed to see if doses lower than 0.625 mg estrogen and 0.625 mg
progestin, the dose that was used in WHI, would be active for symptoms and for
bone loss. Two thousand, eight hundred
and five women were randomized at various doses of Prempro, Premarin or
placebo. The average age was 53. The average time since menopause was 4.7
years. The endpoints included among
numerous things most important reduction of vasomotor symptoms and improvement
in bone density and protection of the endometrium. The bone density substudy which I'll show in
the next slide included 800 women who were followed for two years. Much of the data from this study have been
published.
Dr.
Lindsay's publication in 2002 showed the
Prempro improves bone density in all doses.
On the left panel is the bone density in the spine. This declined in the placebo group which was
expected. That's that blue line that's
going downward. But it increased in all
the time points starting at six months in the women who received 0.3 mg, the
red triangles, 0.45 mg, the purple squares, or 0.625 mg. That's the dose of Prempro that was used in
WHI shown by the green diamonds.
At
the spine, the 0.45 dose, the purple, increased density about two percent. The 0.625 dose about three percent. All the differences reached significance
compared with placebo. On the right
panel are data from the hip. It's the
same colors. Again bone density declined
in the placebo group. In contrast, bone
density was increased by all the doses of Prempro. In this case as with the spine, all the
differences reached significance compared with placebo at the time points
starting at about one year. By 24
months, the results for all the three doses were very close to one
another. Moreover the increase in
density compares favorably with data from studies of raloxifene and
bisphosphonates and I won't show you that data.
Now
you've heard this in detail already today.
Many epidemiology studies concluded that estrogen/progestin products
were associated with a decrease in fractures in women. WHI provides evidence that fractures are
indeed prevented even in osteopenic women.
I took these numbers from the publication. All fractures were reduced by 24 percent. Hip fractures reduced by 33 percent. Vertebral by 35. Arm and wrist fractures by 29 percent.
But
the data also indicate a very reliable and robust effect. Now I emphasize these data today because part
of my job is to explain how we responded to the WHI results. Now of us on the medical team thought that we
could or should ignore the highly favorable fracture results.
1. It was particularly impressive that these
results were achieved even though low bone density was not a requirement for
study entry. Only about four to six
percent of the women were osteoporoic.
Generally we studied bone sparing agents in osteoporoic women. So
this is a first study to demonstrate such a benefit in osteopenic women. It's consistent with what I told you in the
last few slides about fractures in osteopenic women.
2. The fracture incidence was probably
underestimated. The endpoint was
clinical fractures. I think this has
been explained already. Most studies we
do for regulatory approval includes fine radiographs so we can detect
subclinical fractures. Of the women who
have a radiographically identified fracture, about 15 to 20 will develop
another fracture within a year or two.
3. The reduction was observed within the first
year of treatment. I'm not telling you
something that you don't already probably know, but what I would emphasize is
these are the data that we evaluated in making our decisions.
So
there is convincing evidence that estrogen/progestin can prevent
fractures. Let me just summarize these
points again. There is rapid bone loss
in early menopause. Fracture incidence
increases as density decreases. Most
fractures occur in women who are osteopenic.
Prempro improves bone density in osteopenic women close to
menopause. That's what I showed you from
the HOPE study. The WHI shows that
Prempro reduces fractures even in women who are not screened for osteoporosis.
Now
of course it's 2003. It's likely that
every clinical decision includes some discussion about WHI. Practitioners need to know about it. They read about it. It's featured in numerous journals. It's a subject of CME. Women have learned about it through the
media. The results are featured
prominently in the Wyeth Prempro Prescribing Information. The most recent version of the label is part
of that background and it's also on the website.
But
as I stated in the beginning, point four if you remember, applying the results
of a clinical trial really requires informed clinical judgment. There are some limitations to the evidence
that are related to differences between a clinical trial and between clinical
practice. The investigators who spoke
this morning actually alluded to some of these.
Again
I want to point out the medical team at Wyeth reviewed and discussed the WHI
data at great length, internally with the investigators, with the NIH team,
with the FDA. We acted on the data last
year by amending the label and supporting dissemination of the WHI data. You'll see how we did this too. But the medical team doesn't agree fully with
some of the broad interpretations of the data, particularly some of the
statements about the application of the data to all clinical practice
especially some of the subgroup analyses.
Now
we know that the subgroup analyses are supposed to be hypothesis
generating. They are not supposed to be
definitive. But one of the problems is
that in clinical practice the women whom you actually see come from one of the
subgroups or they have characteristics of one of the subgroups and some
characteristics of the other. So you
have to make an individual judgment.
These
are the four points I want to make about the WHI study and about how to apply
the data from that study to clinical practice.
1. To remind you in general, the women who
receive hormone therapy than the average age of the women in WHI. I know some younger women were studied in
WHI, but in fact the most robust effects were driven mostly by the older women
and they have menopausal symptoms, the women in general in practice who receive
hormone therapy.
2. This one was also discussed earlier in the
morning. The risk/benefit assessment in
WHI didn't take into account all vertebral, that includes the clinical and morphometric fractures, and
all of the nonvertebral fractures as well as some other benefits and risks. It was defined prospectively but it wasn't in
fact selected.
3. Dr. Anderson referred to this one
already. The global index from WHI is a
clinical trial tool, but it cannot be used to assess the risk/benefit in
individual women.
4. The data provide important information, being
a little bit repetitious, but clinical practice requires individual patient
judgment.
Let
me take these one point at a time. The
first point, most women who take estrogen/progestin are younger than women in
WHI. In the Women's HOPE and the other
studies of estrogen/progestin in menopause, the women in the study were within
five years of menopause. In general,
that's because we tried to enroll women in the study in whom we can demonstrate
a benefit on vasomotor symptoms, but this age group is approximately ten years
younger than the average age of the WHI population. Again the robust effects were driven by the
average of the population. The average
age in the Women's HOPE study was about 53.
The average age in the WHI study was about 63. The women in Women's HOPE were closer to
menopause.
That's
point number two. The women less than
ten years since menopause appear to have no excess cardiac risk. Now I'm pointing that out because when you
look at the paper for cardiac risk, it does look as though the women less than
ten years have no excess cardiac risk and it's consistent actually with some
common sense clinical practice, some things that we know about age related risk
of cardiovascular medicine. Again it's a subgroup analysis of the younger
women, but the fact is that if it's hypothesis generating, one of the
hypotheses could be that younger women have less cardiovascular risk.
In
the absence of being able to make a clear demonstration of that fact,
physicians and practitioners have to be able to make a decision for the
individual woman. That's my point, not
to have a discussion about the pluses and minuses of a subgroup analysis. It's to have a discussion about when you're
finished with the subgroup analyses, how do the physicians use the data that
you give them. It generates a hypothesis
that the younger women closer to menopause may have a lower risk of using the
estrogen/progestin.
The
final thing is that in the younger women symptoms and osteoporosis are more
likely to coexist and estrogen/progestin is the only therapy that can
concomitantly treat menopausal symptoms and prevent osteoporosis. Remember women will come to the physician
partly because of a desire to treat a condition or a symptom or a problem, not
just to be put into a trial for a long term prevention. So there will be a medical issue to address
at the time.
I
don't want to belabor this but the risk/benefit assessment did not take into
account all of the osteoporoic fractures.
The failure to do that when you calculate the global index may
underestimate the benefit of hormone therapy for osteoporosis in general.
That's
not really the point about adding up the global index. The point that I want to make and also what
the medical team thinks about is that the disability from any type of fracture
may have a significant impact on an individual woman. It may change the individual risk/benefit for
estrogen/progestin. That's what actually has to be decided when someone
wants to write a prescription.
Let
me talk a little bit about the WHI global index. Dr. Anderson alluded to this. It's a clinical trial tool. It's not really a risk management tool for
individuals. It serves the purpose of a clinical
trial, but it wasn't designed to serve clinical practice. I just want to point out that clinical trials
evaluate the population. That's what we
analyze. That's what we look at. That's what we add up. But clinical practice considers the
individual risk/benefit.
I
alluded to this earlier. The individual
may or may not match closely. The actual
population that was evaluated in the WHI trial may not match the
subgroups. The age of the woman, the
BMI, the time for menopause, the menopausal symptoms, the degree of osteopenia,
the perceived need for osteoporosis prevention are differences that may
characterize an individual and it may be very hard to characterize actually all
of those differences in the population analysis that we do. So extending the results beyond the trial
population really again when all of the discussion is done requires that the
practitioner use judgment.
Leading
to my next slide, the data provide guidance, but clinical practice requires
individual patient management. Now based
on all of the data from this study and the other studies, I think the decision
making process would be as follows:
1. The decision to use estrogen/progestin in
menopause will be influenced by the presence, the severity of symptoms and the
bone density measurement. The potential
benefit of estrogen/progestin therapy on bone health should not be ignored in
younger women in early post menopause, but the physician and the woman have to
evaluate the benefit in light of the potential risk of vascular disease, stroke
and heart attack and breast cancer. The
individual risk has to be considered.
2. The use of estrogen/progestin in women with
bone loss but no menopausal symptoms will have to based on the need to
treatment women at high risk. We heard
that the highest risk that was evaluated in WHI may not be the highest risk
that will actually be seen in practice. Still those are the women who have to be
treated. Also the consideration would be
the unsuitability of the other handful of agents that are available. This actually isn't too far away from the
recommendation that was made by Dr. Cauley.
So
let me summarize this section. How do
you apply the data from WHI and a lot of other clinical studies to clinical
practice and the individual woman?
First, remember the women who take estrogen/progestin in general are
going to be younger than the average age of the study. The risk/benefit assessment did not include
all the fractures and a particular kind of fracture or a concern about a
fracture may be important to a particular woman in practice. I just want to remind you again that the
global index from WHI is a clinical trial tool, but it's not being advocated as
some way to determine the risk/benefit for each woman. That still has to
be done. The data provide guidance. Clinical practice requires individual patient
management. The product information
which is going to be the subject of my next section provides the information
useful for practice decisions. Finally,
estrogen/progestin in our estimation after evaluation by the medical team
remains an important therapeutic option for osteoporosis.
I
want to talk about the product information specifically now. Let me start with one very important point
about the product label. The medical
team developed a label that is clear and balanced. It is the company's policy to revise the
label when appropriate. Now I'm
presenting the medical team's point of view which is that the current label
accurately reflects the state of knowledge and the recommendations consistent
with the evidence.
I
want to go through these four points.
1. The product information strikes a balance so
that the clinical practice is guided but its use is not appropriately expanded
or limited. Those are important.
2. The label information for prescribers
includes some recent results from a variety of clinical and epidemiological
studies. There's a lot of data on the label.
3. The balance includes statements regarding the
risks that have been reported and, with regard to safety, a conservative
interpretation is presented.
4. New data are considered for inclusion as they
become available. That's exactly what
happened last year when WHI became available and we worked with FDA to make
changes in the label. That's exactly the
process.
Now
the recommendations for Prempro use are based on the evidence that we have
today. For women with menopausal
symptoms, Prempro can reduce symptoms and prevent bone loss. We say that and we cite the clinical trial
results on bone density. For women
without menopausal symptoms, Prempro is recommended only for women at
significant risk for osteoporosis and for whom non-estrogen treatments have
been considered. This change was made
based on the results of WHI after consultation with our medical team and with
the medical team of the FDA.
Let
me be more specific. What does the
indication actually say? Prempro or
Premphase is indicated for:
1. Treatment of moderate to severe vasomotor
symptoms associated with the menopause.
That hasn't changed in the last year.
2. Treatment of moderate to severe symptoms of
vulvar and vaginal atrophy associated with the menopause. This sentence in blue was added in the
labeling as a result of the WHI. It says
that "When prescribing solely for the treatment of symptoms of vulvar and
vaginal atrophy, topical products should be considered at the same time."
3. This indication about preservation of bone
states "Prempro is indicated for mention of post menopausal
osteoporosis." The sentence in blue
was also added after consultation and review of the WHI data and it says
"When prescribing solely for the prevention of post menopausal
osteoporosis, therapy should only be considered for women at significant risk
of osteoporosis and non-estrogen medication should be carefully
considered."
We
also highlight certain information to promote awareness. Estrogen/progestin should not used for
prevention of cardiovascular disease.
That's very prominent. The risk
of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli and
DVT as reported in WHI and other studies are prominently and repeatedly
noted. Specific information on breast
cancer, coronary heart disease from WHI and other studies and information on
dementia from the WHIMS study are also included. In fact the relevant risk of the outcomes in
the global index which I discussed earlier that was published in JAMA
last July is reproduced in the product information.
We
also recommend therapy should be prescribed at the lowest effective dose. We also recommend that the duration of
treatment should be only as long as required to meet objectives for the
particular woman. As you saw this
morning, a boxed warning was added and that assures that actually the prominent
information is the first thing that's seen when the label is read.
Now
the changes in labeling were accompanied by a communications program. The first thing was that practitioners were
notified by letter of the results of the
WHI and the changes in the product information.
We did that last year. The data
from WHI were distributed to practitioners by mail and the Wyeth
representatives were also asked to distribute a copy if necessary.
Information
wasn't given just to the prescribers.
There's information in the patient package insert that includes a clear
assessment of the cardiovascular disease and breast cancer and other risks that
we have determined are associated with the use of estrogen/progestin. So the patient gets this information as well.
The
question we need to answer is "Has all this made a difference?" The data we have now on the pattern of use of
Prempro is consistent with the new recommendations that have been made in the
last year. I just want to address two
points.
1. About 25 percent of the new prescriptions are
for low dose. We're making a
recommendation for low dose. The low
dose was made available only around July of this year. After about four months after the low dose is
available, 25 percent of the prescriptions are actually for the low dose. So prescribers are following the new recommendations
which is good.
2. The second point is 94 percent of women
initiate Prempro for menopausal symptom relief.
It's very clear on the labeling that's where the use is directed. By and large, the substantial majority
of women and prescribers are using the
product now for menopausal symptom relief so younger women constitute by far
the majority treated.
I
want to emphasize this. The changes in
labeling had the desired impact. This is
very important. When the clinical
research suggested a change in the use of the product, the medical team at
Wyeth responded. We responded with
recommendations that are consistent with the scientific data. The result
as a pattern of prescribing indicates that practitioners have changed in
response to the new scientific data as well.
The
major conclusion I want to leave with you is that our medical team in
collaboration with the FDA has been able thus far to respond to new data and to
accomplish the objective I set out in the beginning which is to support the
appropriate use of this particular product.
My
last slide is just a summary of the key points
1. With the reminder that osteoporosis is an
important medical problem, fractures cause mortality and significant
disability. We don't want to forget that
in our discussions.
2. There are only a handful of treatment options
currently available for osteoporosis.
3. Estrogen/progestin is only one of the
therapies that we know can treat both the menopausal symptoms that occur and to
prevent osteoporosis.
4. We know now that Prempro prevents
osteoporosis and reduces the incidence of all fractures including hip
fractures.
I
want to thank you for your attention. If
there are any questions, I or my team will do our best to answer them. Thank you.
CHAIRMAN
McCLUNG: Questions or comments? While you are gathering yours, let me make a
couple. About the HOPE trial, you've
emphasized that bone loss happens early in menopause and that most of the women
who take estrogen now are younger. The
average time since menopause in that trial is 4.7 years.
DR.
CAMARDO: Correct.
CHAIRMAN
McCLUNG: The bone loss happens most
rapidly in the first three to five years after menopause and then slows
down. You looked at lower doses in the
HOPE trial to show that it was effective in preventing bone loss. Have you actually looked at the women who
were closer to menopause, those within the first three years for example when
bone loss we know is faster and to know whether the lower doses of Prempro or
Premarin are effective in that group of women that you are focusing our
attention on?
DR.
CAMARDO: The question is did we look at
a subgroup of the women even closer to menopause than the average 4.7 years?
CHAIRMAN
McCLUNG: Right.
DR.
CAMARDO: I'm going to have to ask my
team to help me out on that. Dr. Lindsay
or Ginger?
DR.
LINDSAY: The response to your question
is that we did not look at that because we had groups of only 80 in size and it
would be an inappropriate subgroup analysis.
CHAIRMAN
McCLUNG: The other question I'd ask has
to do with the durability of effect. One
of the points that you made is that the recommendation is that estrogen be used
only as long as necessary to achieve the treatment objective. Being treated forever is not a likely
circumstance. Then knowing how long the
protective effect of estrogen and particularly the lower doses of estrogen last
becomes an important consideration. If
patients are at very low risk when they're begun on therapy, treated for three
years or five years and then therapy is discontinued, it could be that the
benefit then last until they are old enough to be at risk. Or does the effect disappear? Have you followed the women since therapy was
discontinued in the HOPE trial or in other studies?
DR.
CAMARDO: Not in the HOPE study. There are actually some data that address
that. I had it in one of my slides but I
won't show it. I think that the
conclusion that we came to is that you can assure the preservation of bone
while you're using the therapy. Once this
estrogen/progestin is stopped, there is a decay period. I think that's actually been published. It's not immediate and it doesn't look like
it's accelerated. What I think will
happen in general and in practice is that if a practitioner and woman make a
decision to use estrogen/progestin for osteoporosis after a certain period of
time which is going to be hard to determine for sure, they will likely want to
stop the estrogen/progestin for symptom relief if that was part of the option
and continue something else for bone preservation. I think there would be no disadvantage to
having used estrogen/progestin.
In
fact, you might argue that there would an advantage because you would be
starting from a higher baseline. I want
to make sure that it's clear that I'm not advocating that if you make the
decision to use the therapy that you have to continue it forever. You can continue for as long as a reasonable
tolerance for the risk, clear benefit and then after that you have to use
another therapy which seems to make practice sense and there wouldn't be
disadvantage. Am I supposed to moderate
the questions? You're supposed to
moderate the questions, aren't you?
DR.
ROSEN: Rosen here. I have three questions, two specific and one
general. How closely tied is bone loss
to menopausal symptoms? You've tied that
in several occasions, especially rapid bone loss. Can you establish for us what that connection
and if you're trying to treat both at the same time, can you be sure of that as
a clinician?
DR.
CAMARDO: I'm going to give you part of
the answer and I'm going to ask if maybe Dr. Gallagher could help me with this
because he actually is a clinician in practice.
What we've seen is that if we do a study, we screen several thousand
women on the basis of symptoms. We
manage to find a reasonable percentage of women who actually have osteopenia as
well. So they are concomitant. It's a very common event in practice, but if
it's okay, I'd like to ask Dr. Gallagher to respond.
DR.
GALLAGHER: Dr. Gallagher, Creighton
University, School of Medicine. About 50
percent of women will complain of vasomotor symptoms during the menopause and
maybe 40 percent will complain of vaginal dryness (dyspareunia). Certainly from the HOPE study, we know that
the great majority of women actually develop bone loss so they are coincident
conditions.
DR.
ROSEN: I'm just a little concerned about
the term "rapid" bone loss because as you know, Chris, this comes up
all the time. How many of these people
are actually losing bone rapidly and what is that definition?
DR.
GALLAGHER: I think that the common
figure that goes around and Claus has certainly pointed this out is that 25
percent of women have rapid bone loss after the menopause. Still there's a considerable portion who are
having somewhere between average and that.
So we're talking at least 50 percent.
Just a point of information for the women in the HOPE study, the average
number of years for menopause was 2.7, not 4.7.
CHAIRMAN
McCLUNG: Not 4.7?
DR.
GALLAGHER: No.
CHAIRMAN
McCLUNG: Let me ask to follow through
with Cliff's question. Is there a
relationship between women who are symptomatic and the rate at which bone loss
occurs? Is that question that you were
asking?
DR.
ROSEN: That's right.
CHAIRMAN
McCLUNG: So we appreciate that the bone
loss happens after menopause. We appreciate
that many women have symptoms. Do the
women who have symptoms lose bone more quickly than those who do not
symptoms? I think that's Dr. Rosen's
question.
DR.
GALLAGHER: I think I'd like to hand the
microphone over to Dr. Christiansen.
DR.
CHRISTIANSEN: There's a tight relation
between rate of bone loss and estradiol concentration. There's also a tight relation between serum
estradiol and the symptoms. None of
that's close as to the rate of loss but those are very significant. Therefore of course, there's relation between
symptoms and rate of bone loss. We have
shown that many years ago.
DR.
ROSEN: Okay. I just want to finish with two very quick
questions. I'm not sure I understand
what you're referring to when you say "WHI did not address some
non-vertebral fractures." Can you
clarify for me what you're talking about "didn't report some non-vertebral
fractures"?
DR.
CAMARDO: Yes, what I was referring to is
arm and wrist fractures. I mean included
in the index calculation. I did not see.
DR.
ROSEN: In the global index.
DR.
CAMARDO: In the global index.
DR.
ROSEN: But it's very important to
appreciate that they reported all non-vertebral fractures that are
standardized.
DR.
CAMARDO: Yes, they did, but it wasn't
included as part of the side of the benefits.
DR.
ROSEN: I have one philosophical question
because I am a practitioner as well. I
don't quite understand why you make the distinction between what we see in
clinical trials and what we do in practice.
Can you tell me a little bit about that reasoning? It seems to me that we have to base what we
do in clinical practice on what the evidence is. So you constantly make that distinction. This is what's in the trial. This is what we do in practice. Can you elaborate a little bit on that?
DR.
CAMARDO: I probably should have included
my original slide which was a quote about how there are consensus guidelines
that are developed on the basis of trials.
Applying the guidelines to actual patients sometimes can be difficult.
DR.
ROSEN: Oh, I'm not a fan of
recommendations or guidelines but each of the practitioners has to weigh the
evidence.
DR.
CAMARDO: I don't disagree with you at
all. I think the practitioners have to
weigh the evidence. In general, when you
do a trial, you have defined a population and you have taken certain steps to
make sure that the population fits into the criteria that you've set up. Actually if you set up a trial and try to
find the people that you want to get into it and you go into a practice, you'll
find that a lot of the people may have the disease that you're trying to treat
but they don't actually fit in the trial. So you have set up a situation
that requires that the results be applied with care. That's all I'm really saying.
I
do not want anyone to mistake that I don't believe in the value of clinical
trials. Wrong. That's absolutely not
true. But I still think when you take
the data you have to let the practitioners apply them. That's what I want to tie to our product
information because we feel strongly that we need to provide the information
balanced.
CHAIRMAN
McCLUNG: Ms. Solonche.
MS.
SOLONCHE: Yes. Early in your presentation, you showed a
slide from a 1976 article in the Lancet.
The title of it is "Bone Loss Follows Estrogen Loss and Can Be
Prevented With Early Use of Estrogen."
I see that all the participants in this seem to have had oophorectomies.
DR.
CAMARDO: That was the study actually.
MS.
SOLONCHE: My question is the studies
that you've used since then and the WHI study, are these people who have had
oophorectomies, surgical menopause; or are these women who have what we'll
aphoristically call "natural menopause"? Do you think that makes a difference in the
results?
DR.
CAMARDO: The latter, natural
menopause. I think it probably does make
a difference in the results, but I really used the 1976 paper as a model for
looking at intervention at a time point when you could determine when estrogen
had disappeared rather than over time.
So it was really a way of looking at a specific question about the time
point of estrogen replacement when it was known when estrogen loss
occurred. That was a particular
situation just to test the value of estrogen.
In the study participants in Women's HOPE in general are women who are
going through menopause, not women who ovariectomized.
MS.
SOLONCHE: Thank you.
CHAIRMAN
McCLUNG: Dr. Follman.
DR.
FOLLMAN: You were saying that you didn't
like the idea of using the global index to help tradeoff the risks and benefits
for an individual patients. The reason
you gave was that really this index had been designed more for monitoring of
the trial. Now it's being put to another
purpose. I was wondering if you had any
other reasons why you didn't like the global index or making this
individualized risk/benefit tradeoff and if you had thought about a different
quantitative way of making the risk/benefit tradeoff because a large part of
what we hear today is trading off risks and benefits.
DR.
CAMARDO: That's a good question. I think actually the WHI investigators, not
just I, pointed out some of the limitations of the global index. I found it a complicated endpoint for the
trial. I think the medical team would
agree with me that it didn't evaluate the benefit of the intervention the way
we often evaluate the benefits of intervention which is to see what they are,
define the magnitude and then have a discussion about whether the risks make it
worth it. They decided really on the
basis of a number which you can't just apply to a woman who walks into the
office I think. That's in all
cases. It's just a matter that it tends
to want to homogenize the results here and it wasn't designed to be a
tool. It's not like the Gail index or
the Framingham. Those things assessed
cardiac risk or breast cancer risk. It
really isn't that. I don't think it was
designed to do that.
DR.
FOLLMAN: So I guess you're saying you
don't want to use that index and just look at all the data, look at the risks
and benefits for the different endpoints and then make some gestalt decision
based on the patient and her profile and all this information from the WHI and
other studies.
DR.
CAMARDO: The recommendation we are
trying to make is that the data need to be available and that since there are
some areas of gray there is a certain point where a physician would have to
make the decision. I think that would be
a fair way to say "I don't know what I would do if I were in
practice." I'm not in practice
right now, but I believe that there's some gray in that even when you look at
the risks there are some cases where either you could evaluate that the risk is
lowered because of some particular status of the individual such as low blood
pressure, low cholesterol, no history of heart disease, very young and a lot of
reasons that others have alluded to today and decide that maybe the risk is
really low.
There
are other circumstances where I think for an individual woman the risk even if
you take it at face value might be worth the benefit. I don't think we want to make a judgment
about that. I don't want to advocate for
any particular position. I want to make
it clear that our mission is to make sure that the knowledge base is adequately
displayed in the labeling. I'm telling
you what I think the thought process might be.
CHAIRMAN
McCLUNG: We've heard that the global
index was put together at the time the study was started. One of the important things to remember is
that the world is different now in lots of ways than it was ten years ago. Our understanding and even the outcomes that
were expected turned out to be different than were planned and predicted. Dr. Rossouw has already thrown a challenge to
the clinical community that if we can come up with the justification for a
different set of risk factors and benefits to be included in a different global
index. My sense is that much of that
data exists in some database and in your database to allow us to look at
that. So we're struggling with trying to
apply in clinical practice a tool that was put together a long time ago where
our understanding about each of the diseases and the effects of estrogen has
moved on from that time. Please.
DR.
CARPENTER: In addressing risk/benefit
issues, you've shown the recent impact of your data demonstrating that lower
doses of Prempro are effective in preserving bone marrow density and recent
increases in prescriptions for the lower dose formulations. In that this is potentially a very useful
strategy for maintaining benefit and it appears to be motivated by the
potential for reducing risk, I wondered to what extent there is data being
collected and what plans there are to organize or collect that data at the
lower doses for these various adverse actions.
DR.
CAMARDO: At the current time, we have
the database from the study which is about 3,000 women followed for about a
year. That's very small but we have some
assessment of the cardiovascular risk in that study which is relatively small
actually. That's one thing. The only other thing at this point in time is
really post marketing surveillance. We
don't have at this point a study designed that would answer the particular
question to the same extent that it would addressed in the larger study that we're
talking about today. So as you said, we
have the bone marrow density data. We
have the data on vasomotor disease. We
have the side effect data which we know from the HOPE study. At this point in time, the product's been out
for a couple of months so we have mostly post marketing surveillance
reports. That's the extent of it for
right now.
CHAIRMAN
McCLUNG: Dr. Woolf.
DR.
WOOLF: A question and a comment. On one of your slides, you state that the
duration of treatment should be only as long as required to meet objectives for
the particular woman. You've talked
about osteoporosis obviously not meant to be lifelong. But what about flushing? Is this something that a post menopausal
woman for want of a better term outgrow or will this simply return once the
estrogen preparation has been discontinued?
DR.
CAMARDO: I think those are both extremes
of what can happen and everything in between.
I don't want to give you a flippant answer, but in fact what we've done
to try to address that is to point out in the patient information that the
particular objective which is flushing should be addressed on a regular
basis. Our advisors are telling us that
in general - these are the recommendations from ACOG and others - that a yearly
reevaluation be performed and to consider to discontinue in some women. With the discontinuation, flushing will
return. We know that. In others, it does apparently go away.
I
could ask one of the clinicians in practice to talk about that, but the way
it's been addressed is actually in the patient information. We advise that a discussion occur with the
practitioner about whether you still need treatment. That generally refers to flushing because
that's the most apparent one. There are others. The implication is if you don't need it
anymore for flushing see if you don't.
You have to try that.
CHAIRMAN
McCLUNG: Dr. Schade.
DR.
WOOLF: My comment about the global index
really doesn't pertain specifically to Wyeth or WHI but my understanding about
an index is you develop an index from a population base and then you go and
test it against another population base.
From what I can gather, this has not been done with the global
index. It was simply meant to be a tool
for deciding the severity or the risk and benefit but it really hasn't been
validated in another dataset. To use it
as a tool to decide risk/benefit when it hasn't been really tested in a new
dataset to see its validity may in fact not be appropriate.
CHAIRMAN
McCLUNG: Any other comment about that?
DR.
ANDERSON: I would like to comment. I think what you were talking about in terms
of developing and validating in another dataset has to do with more a risk
score such as the Gail model or the fracture risk score that they were talking
about where you're trying to identify risk factors of individuals and put them
together to then make a simpler stratification of individuals.
The
global index is something quite different where it's trying to summarize
treatment effects, not individuals. It's
a summary of those benefits and it's a valid comparison of the randomized trial
endpoint. It's a disease free survival
statistic where the disease now is actually the whole list of diseases that
we're looking for. That's what it is.
DR.
WOOLF: But my point is that this
distinction is liable to be lost on the public and that it is becoming in fact
the Gail index or some other index of global disease. In fact from my reading of the New York
Times and my local paper, the Philadelphia Inquirer, that's exactly
what's happened. It's become the marker
of treatment that it has become a validated instrument to decide whether to use
estrogen or not. The statistical nuances
are clearly lost on the public. It's
hard enough for me to understand. I
don't know if I do, but that information is not getting across.
DR. ANDERSON: Yes. I
would say probably none of us here want to take complete responsibility for
what's in the newspapers. It's clearly limited
in the sense that it was designed for this trial and never meant to go any
further.
I
would say that it's a very valuable tool for looking at the risk/benefit
profile in a philosophical sense to have some summary index of these because we
need quantitative measures of risks and benefits to help in evidence base
medicine. I would say in defense of this
product is that we lack that similar risk balance information for a lot of
other products out there. We need to
move forward to have better information like that on all these products
particularly for prevention work.
Prevention
work is some of the toughest. You never
know with the patient that you're treating for those clinicians if you give
them this medicine whether you actually prevented that disease or whether they never would have had it in the first
place. The prevention is really
population-based work. I'm not sure that
I really agree with this individualization for prevention purposes. For treatment, it's a different argument, but
I'm going beyond my scope.
CHAIRMAN
McCLUNG: Okay. Great.
Dr. Schade.
DR.
SCHADE: I have two short questions. You showed us data on the lowest dose of
estrogens. What about a dose response
curve for symptoms and the estrogen dose?
You didn't show us that. You
showed us with the bone mineral density.
In other words, does the dose response curve look similar to the BMD
response?
DR.
CAMARDO: I'm going to ask for this
specific question about the study Dr. Pickar to just remind me of the results
for the dose response for symptoms if you could do that.
DR.
PICKAR: When you look at the doses of
Prempro that were studied for menopausal symptoms, they were all very similar.
DR.
SCHADE: All right. I think I asked that question because
obviously there is a push for the lowest dose.
We're seeing reasons for that even though right now at least the
prescriptions don't reflect that. That
may be as you point out on your slide that the product hasn't been available
that long. The other question I have is
on labeling. It's probably my
ignorance. You use a term "should
be seriously considered." In other
words, what does that mean? I'm a
practitioner and basically when you have a choice of treatments in every case
you should seriously consider all the treatments and choose the optimal
treatment. So it seems to me on the
label unless that's a term that the FDA has utilized in many situations that
I'm not aware of but as a practitioner that doesn't say very much. I just wondered about your interpretation of
that "should be seriously considered" statement.
DR.
CAMARDO: It is just short of requiring
that an alterative agent to tried and shown to fail or be ineffective. Our medical team discussed this a lot. There's a regulatory implication to some of
this which I think will be discussed later.
It falls short of requiring a demonstration of failure. We thought about it and discussed it and came
to the conclusion that there are some cases where it wouldn't really make sense
for us to recommend that another product be tried and fail first when you could
choose among ?- We thought it was sufficient to recommend choosing among the options
which is not something that was ever said about the product previously and it's
usually not said about products. It's
usually assumed. We explicitly state
that. The reason we were short of
demonstrating is that we thought that there are some cases where you could
predict that the products might not work anyway.
Now
I should tell you there is another discussion about the older women which I
would just like to mention briefly. In
older women because of the incidence of dementia in WHIMS, we're actually
discussing the possibility of requiring that other agents actually be used
first because in the older women, there seems to be a different risk/benefit
implied by the results of that study.
We're discussing actually in that case maybe we should go on the other
side of that recommendation and make it a little bit stronger. But it's a bit of a fine line and as said,
some of the evidence suggests that you just make the recommendation to
consider. Other evidence seems to
suggest that you may want to make the recommendation to try other
products. Does that make sense?
DR.
SCHADE: Yes. Now I understand at least what you mean.
DR.
CAMARDO: Okay.
CHAIRMAN
McCLUNG: Dr. Stadel.
DR.
STADEL: Yes, I just have a further
question on the issue of summary risk assessment. As I recall from the presentation of the
fracture data in the group that was defined as being at high risk of fracture -
it got pretty close to one - the global index was still slightly worse in the
treated group than the placebo group, but it was getting closer. My question to you is has Wyeth proposed any
further refined analyses aimed at identifying a group within the total for whom
the net would be beneficial? That's what
I hear you saying is that of course as a practitioner we have to say "How
do the risk characteristics of this patient play against the group experience
that we're using to judge?" Have
there ben any specific recommendations for further analyses using more
refinements of definitions coming from Wyeth back to the WHI people?
DR.
CAMARDO: Yes, the answer is that the WHI
and Wyeth have actually been working on some analyses together with the
understanding that the lead is always going to be taken by WHI in terms of
publication and everything else. So we
tend to be in line after the publication results which is appropriate I
think. But we have asked to look at some
of the higher risk and we've also discussed the possibility of looking at women
who may be at high risk for osteoporosis and low risk for some of the other
side effects.
I
don't think that's an original idea. I
think it's something that we discussed.
I haven't discussed it. Dr.
Stevenson and her epidemiology group have discussed it. The shorter answer is yes. It's a little disappointing though that high
risk osteoporosis doesn't seem to be that high risk compared with the risk
scale. So again you may not see in that
population women who you might see in practice.
That's where the limitation would be.
The answer is yes. We've actually
been discussing other possible analyses.
We've had some ideas. Go ahead.
DR.
CAULEY: Yes, I just wanted to point
out. I think we talked about the high
risk women being older and this brought to my mind when you talked about this
issue with regard to the risk of dementia in the older women. The high risk women that we called "high
fracture risk" were actually in their 70s.
That was the average age. That's
the group where the dementia finding were limited to women age 65 and
over. So caution also when we talk about
including other aspects in the global index.
It's important to include other risks and benefits. That would be something that would be needed
to be included as well.
CHAIRMAN
McCLUNG: Dr. Bone.
DR.
BONE: It seems to me that many of us
have been concerned that our major target population for treatment with hormone
therapy of one kind or another would be the very early post menopausal woman
within the first year after cessation of menses who has symptoms with or
without low bone density at menopause carried forward a limited number of
years, probably something like three or five years during which time we would
have expected most of the symptoms to resolve.
Perhaps the dose could be tapered over that time. It sounds to me like one of the things that
would be extremely useful would be a prospective clinical trial actually
representing that group. WHI has done a
commendable job but it didn't really emphasize the very early post menopausal
women particularly those who are quite symptomatic. This very early phase of bone loss is also an
issue that's been brought up. My
question to Wyeth and it would be a question for sponsors of other products
would be "Do you have any plans to look at that population
specifically".
DR.
CAMARDO: We have plans to continue to
evaluate the low dose. We don't at the current time have plans for a
study of the size and duration of the study we discussed this morning.
DR.
BONE: I'm not exactly sure that it would
be required to obtain quite a bit of useful information about that very
specific segment.
DR.
CAMARDO: It has been discussed. I don't have a specific proposal that would
be ready for discussion by this Committee.
I think if advice goes in that direction then it's something that we
would work out with the FDA medical team to actually determine how big and how
long it should be and what kind of methodologic problems we'd have to face to
do it. I don't want to give an answer
about anything in particular because we've really only discussed it in general
terms.
DR.
BONE: Having taken your point and
understanding that, it's actually who we're concerned about and that's actually
the treatment model that we're most focused on.
DR.
CAMARDO: Okay.
CHAIRMAN
McCLUNG: Other questions or comments? Yes.
DR.
ZERBE: I have a question about total
mortality. There's been a lot of
discussion about the global index and the pros and cons of the various things
that have been included. Total mortality
does not appear to be different. Could
you discuss a little bit about strengths and weaknesses of the use of that as a
prominent feature in the evaluation of the risk/benefit?
DR.
ROSSOUW: Let me start and then Garnet
can follow up and correct me if necessary.
Two points about total mortality.
It's an extremely insensitive index particularly when you're dealing
with a drug entity that has a variety of effects, some favorable and some
unfavorable. By its nature, it's going
to be insensitive. Also in a relatively
short period of just over five years in a healthy population, the chances of
finding a significant effect on total mortality even though disease incidence
may be tending in a certain direction are slimmer.
My
main point is that total mortality may be an appropriate thing when you're dealing
with a high risk population such as a secondary cardiovascular prevention study
where most of the subsequent deaths are going to be due to that specific
disease. As your treatment is effective
for preventing incidence, it will also prevent mortality. We've seen that in the statin trials and
hypertension trials and so forth. For
this kind of drug in a prevention study with a variety of effects in a healthy
population, total mortality, you'd have to have a huge sample size and a very
long follow-up to find an effect.
DR.
CHLEBOWSKI: Maybe just an example from
the breast cancer area where we have invasive breast cancer. We had 349 cancers which will ultimately kill
25 percent of the women even with our more effective therapies now, but that's
going to take a decade. We have eight
deaths now. To come back and ask that
question, we'll have to come back ten years from now. I think that's true for many of these other
events as well. It's a time related
phenomena. It's like waiting for all of
the events to occur or doing a censored analysis.
DR.
ZERBE: Yes. I guess the only thing I suppose emphasizes
that there really is not even the suggestion.
So it isn't really an issue totally of power. There's not even a suggestion at this point
that there's any increase mortality. Is
that correct?
DR.
CHLEBOWSKI: (Off microphone.)
CHAIRMAN
McCLUNG: Dr. Camardo. Thank you very much.
DR.
CAMARDO: Thank you.
CHAIRMAN
McCLUNG: We are just ahead of
schedule. Are there other questions that
we have for the WHI group? With Dr.
Rossouw's permission since we cut that short, I'm going to make sure we have
our queries and information lined up before we deliberate later on.
Yes. Dr. Woolf.
DR.
WOOLF: Just a clarification. I recall a slide that has been shown a couple
of times regarding the incidence of fractures versus the number of women who
fracture in relationship to whether they are in the osteopenic or osteoporoic
category. I believe one of the slides
demonstrated that there are a greater number of fractures in the osteopenic
group. I wondered if that holds up for
both placebo and hormone treated women and if there is a discrepancy there, how
one might explain it?
DR.
CAULEY: That wasn't WHI data.
CHAIRMAN
McCLUNG: No, that was from the NORA
study so it was not a treatment study.
It was just an observational study, but a number of studies were shown
that as was pointed out the total number of patients experienced hip fractures
for example who have osteoporosis is less than half of the hip fracture of the
population. That's because there are a
lot more younger people. So while the
absolute risk is higher in the group of patients with low bone density and
osteoporosis, the proportion of the total fracture burden falls in younger
people at lower risk. If the relative
risk reduction with intervention were the same across the spectrum of risk,
then the number needed to treat to prevent fractures would be a lot greater of
course in the osteopenic population than in the osteoporoic population. That's just the way risk is about that.
The
other facet about that is that when you look at all fractures the distribution
of the types of fracture also changes substantially with age. In several epidemiologic studies in women in
their 60s, hip fracture and spine fracture constitute a very small proportion
of the total fractures. In the WHI, only
15 percent of the total fractures in either of the groups were constituted by
clinical spine fracture or hip fracture.
So 85 percent of fractures were other fractures which to many of us at
least my personal view probably have less clinical import than do hip fracture
and spine fracture.
In
contrast in women in their 80s, the majority of fractures that occur are hip
fracture and spine fracture. So not only
does the risk of fracture increase with age but the distribution of the types
of fractures and the severity of the types of fractures increases with age as
well. That's often not factored in or
expressed in the sorts of data that we see.
DR.
ROSEN: Mike, can I clarify something?
CHAIRMAN
McCLUNG: Yes.
DR.
ROSEN: The point is that there are many
more people who are osteopenic than osteoporoic. So the number of fractures on the Y axis is
going to be greater. That's just when
you refer to number of fractures versus absolute risk. That's the difference. I do want to point out. Jane had a slide that she took out but the
number needed to treat ?- Maybe you can talk about it, Jane, the number needed to treat because
estrogen does work across prevention populations. It is important to emphasize that point from
your data.
DR.
CAULEY: The slide that Cliff is
referring to is I just calculated the number needed to treat ("NNT")
in WHI for clinical vertebral fractures and compared it to the numbers that
were in the Osteoporosis Research Advisory Group ("ORAG")
report. Now the problem with doing that
is that other report included morphometric vertebral fractures and we only had
clinical vertebral fractures. And the
populations varied markedly. They define
low risk in that report as BMD. They had
BMD measurements on all the women. So it's difficult to compare numbers needed
to treat across the different agents and across the different trials.
But
it did show that in this calculation about 800 women would be needed to be
treated for two years to prevent one clinical vertebral fracture in the WHI
population. I say that with some
limitations, no inherent and calculating NNTs and in the fact that we were
limited to clinical vertebral fractures.
CHAIRMAN
McCLUNG: That's a good point. Let me just come back and emphasize for the
sake of what our subsequent discussion will be that NNT is not an index of
therapeutical efficacy because it's driven almost entirely by the risk in the
population rather than by the effectiveness of the drug. So the WHI as a very low risk population
would be expected to have a high NNT as opposed to lots of other trials where
patients are specifically recruited and enrolled in the study. From a cost effectiveness standpoint, that
mostly reflects the population being treated rather than the therapy being
considered.
DR.
ROSEN: Actually I was going to make the
point that if you look at the NNTs in the ORAG trial they are up over 2,000 for
the bisphosphonates and only 800 for estrogen.
So in a low risk group of people, actually estrogen looks like it does
very well. I think it's just consistent
with the data and again thinking about the caveats that we talked about already
in terms of different populations.
DR.
ROSSOUW: If there's a minute, I can't
refrain from picking up on a discussion that panel members had earlier and
stimulated Dr. Camardo's presentation which essentially says that practitioners
are back to making individual judgments based on what they think the risk profile
is of the patient. We did this trial in
this population to get some real evidence to help physicians make that judgment
in an older population on average. I
think those are very useful and you've seen how practice has changed as a
result of that new evidence base.
It
seems to me that if we now focus in on the younger patient who is symptomatic
to fall back and say "We don't really have good data in that group and
we're still back to seat-of-pants clinical judgment" is a an
unsatisfactory situation. Now the data
that we have in WHI is actually the best data available at this point even for
that population. It is the best data.
Now
for osteoporosis our data are perfectly consistent with smaller studies. That's not the issue. The issue is the non-osteoporoic outcomes,
the cardiovascular and the cancer outcomes.
Just to throw it back on the clinician and say "We don't have good
data on that so make your own judgment" seems unsatisfactory.
Now
it does seem to me that where it's going now with most bodies and why the self
recommending shortest period of the lowest possible base is a perfectly
sensitive clinical thing to do. As I
say, it makes a lot of sense, but can we be sure that the adverse effects are
in fact less? Now they probably are less
just by virtue of the fact that this is a younger population and a healthy
population so one could make a very valid argument that the absolute risks are
low.
So
even if there is a E + P associated effect, the benefit for symptom relief and
osteoporosis prevention you can assume that the benefits can outweigh the
risks. As we've learned, assumptions are
tricky things. So when people say,
"We really need a large clinical trial to address this specifically"
I must say I personally resonate to that which is not volunteering NIH to do
the trial of course.
CHAIRMAN
McCLUNG: All right. Before we take our break, the final formal
presentation will be the FDA review of the WHI data and comments and Dr. Stadel
will lead that discussion.
DR.
STADEL: As a clarification, my comments
as a reviewer as a large of my job here has been to work with Dr. Rossouw in
communications about the NHLBI WHI presentation here. I've been intensively enrolled in reviewing
selected parts of the data. My comments
now are really though intended in a little broader sense. I just reflect for a moment on the purpose of
the trial which was to test the notion that there was widespread
cardio-protection. It was designed to do
that and did that. The purpose of this
meeting is the implications with regard to the osteoporosis indication for the
drugs. Those two are related but they are
not identical.
So
in going to that focus, let's look for a moment just as a reminder at what is
currently approved by combination estrogen/progestin drug products. I merely put this up to emphasize that one
drug product dose was chosen for study.
I don't disagree with that. I
just want to emphasize that the class labeling and then the considerations of
future testing apply to a diverse array of doses and formulations including
both the medroxyprogesterone and 19-nortestosterones in the various doses of
estrogen in the combination products and also in the estrogen only products,
the additional consideration of transdermal versus oral administration for which
there are various bits of evidence suggesting that there might be some
differences. One of the questions to the
Committee is their deliberations about what kinds of things should be
emphasized in the development and testing of new products. I'll raise that as a global comment.
Before
going ahead, the next slide I'd like to show is just the drama essentially of
the historical event. This shows total
prescriptions per year for Prempro 2.5 and 5.0.
I combined them. It's mostly
2.5. For the Prempro low dose and for
Premphase also and for the newer formulations also. Now as you can see, you have this enormous
increase from 1995 on the graph and then in 1998, you have the publication of
the first major paper from the HERS trial.
That's where I think you begin to see the cresting of the wave.
The
acceleration slows down, tops off and then in July 3, 2000 you have the second
paper from the HERS, the long term outcome paper and then on the 17th,
the first paper from the WHI. So you can
see on the national picture the very widespread of use of this medication. Dr. Rossouw had referred to the diverse
practitioners who were prescribing at the time.
In one area, we have been dealing with a public health issue having to
do with the widespread use of the drug in an effort to prevent cardiovascular
disease. I think the trial myself
accomplished its goal in that regard and I think the prescribing data indicate
an appropriate response on the part of the medical profession to learning that
the observation data were not sustained in a large randomized trial.
I'd
like to now comment briefly on the breast cancer data because I've been very
involved in discussing this with the investigators. This is a very simple rendition of what was
presented in a far more elegant and far more statistically rigorous fashion by
Dr. Anderson. I put it up this way for a
particular reason and that is to emphasize my view that absolute differences
are the appropriate way to communicate risk in the clinical application.
That
relative risk especially when presented as percentages can easily be
misunderstood by people who do not work with them on a regular basis. A change from 2:10 to 1:10 and a change from
2:1000 to 1:1000 have the same relative change but a vastly different
meaning. That's a simple statement but
it's one that I recurrently see a problem with in looking at editorials and the
popular and the lay press information on this topic. I wanted to take this opportunity to stress
it.
In
the women who had prior use, the top group here there was an over the trial of
1.22 percent difference in breast cancer.
I've done a very simple approach to the statistics. I thought that Dr. Anderson's modeling that
used observational techniques was appropriate to a safety outcome where there
are unexpected things and one has to retrofit.
That did show some rigor in there being a difference between the two
groups. I think the difference is fairly
apparent that in the large number of women in this trial about 74 percent of
the patient population. The duration of
exposure only on trial the net was two
percent and not very impressive as a statistical finding.
Now
this doesn't contravene that they're of the notion that it's long term use that
matters. The prior use contributes. And it contributes something that we don't
fully understand. Notice that the group
with the lowest rate was the group that had the prior stimulus and then went on
placebo. One interpretation is that the
prior stimulus had stimulated cancer in susceptibles and then the remaining
group when they went on placebo were at fairly low risk. That's a possibility. There are other possibilities.
The
highest risk is in women who had prior use and continued on use. That is entirely consistent with the notion
that very long term use of estrogen/progestin produces an increase in breast
cancer. There's no disagreement with
that.
However
I think it's important to note that in the women with no prior use the rates
are in the middle. So there's a message
to a very large number of women in the country who only use this product after
it was approved by the FDA and whose use would have fallen largely within the
duration of use accompanied before the trial was stopped. I thought it was stopped at the appropriate
time in that regard. There's a message
to those individuals that if they have incurred an increase in breast cancer
risk it is not a very large one and it is not a very clear one.
The
next very important issue that comes to mind is what happens when women
stop. This is of great practical
importance to women who were taking the drug who may have revised their
feelings about benefit/risk. What
happens when they stop? Now this is a
slide from the Million Women Study that was referred to earlier. This is
not a trial. It is an observational
study. I think it's a good observational
study.
The
graph here is one which shows the risk in the top for never users as one and
for past users by duration of use there is no increase of risk except for one
little blimp at five to nine years.
Current users of estrogen only there is a slight increase in risk in
these data and a much more pronounced increase with the combination. So in that regard, it's quite consistent with
the experience of the trial.
DR.
SCHADE: Excuse me. Could you use a pointer because I can't read
the slide from here.
DR.
STADEL: I'm sorry. I had a lot of trouble figuring out how to
make this. This is never users. This is past users whose duration was less
than a year. One to four years. Five to nine years. And greater than ten years. So it's pretty flat. This is the same sort of data for women who
used estrogen only. One to four
years. And at ten year, there's an
increase. It doesn't go up much with
duration sitting around 1.3ish. 1.2
here. 1.25. I tend to round them off.
Now
in contrast for the estrogen/progestin group, it went up from less than one
year of 1.45 up to over 2.0 when you go up to five to nine and greater than ten
sitting out here in these data. Then of
unknown HRT, I don't think is entirely relevant to this discussion.
So
my main reason for showing this is twofold.
1. The current use findings are consistent with
what's been reported from the randomized data.
2. The past use data are quite flat by duration
of use.
I
would like to also show the next slide which is from the same study. This is never users. This is all current users. This is all past users of less than five
years, five to nine years time since last user.
Less than five years since last use, 1.04. Within this if you look at less than one year
since last year, the relevant risk is 1.15 and it's statistically significant
reported in the text. Again I think
these findings are consistent with what we're seeing. It provides some hope for the notion that
when the stimulus is renewed the increase in risk stops. That we need very much to see more follow-up
of the WHI trial data, but that's the best interpretation I can give at the
present time.
Also
when this was looked at separately for past use of estrogen only and past use
of estrogen/progestin, there was no increased risk. You could not isolate that by past use of
less than one year duration in the way they presented the data. So my only reason in raising this is that the
overall results from breast cancer are rather less frightening than one would
get from reading some interpretations that I have seen.
I'd
like to go on now. I only have a couple
more comments. One is a well known
element that needs to be considered in this whole issue. After menopause, there are many papers
showing that the major source of estrogen after menopause androstenedione
mostly secreted from the adrenals and
and aromatized to estrone which then equilibrates with estradiol.
It's in adipose tissue. I think
most people believe it's in the stromal cells where aromatized enzymes are
located.
It
is widely believed in many papers that this accounts for the positive
association between post menopausal breast cancer and obesity. Why is this important? It's because the amount of estrogen that
women make after menopause depends on their amount of adipose tissue and the
functionality of their aromatizing enzymes.
So if you give a specific dose of estrogen to someone who has estrogen,
you could expect clinically that you might get a different response than if you
give that same dose of an estrogen to someone who doesn't have estrogen.
Now
I'm going to go to my last view here and this is something I very much hope
that I'll hear opinion from members of this Committee from your endocrine
backgrounds and others. These are just
two references that I pulled out that relate to this issue. In particular, Cummings, et al. using the
osteoporoic cohort study did an investigation in what's called a case cohort
analysis, a technique that's not terribly important here. But what they said basically was points
straightforward. They measured serum
estradiol levels and the really high risk of fracture was in people who had
virtually undetectable levels.
So
I'd ask a question here. We're talking
about "What should be done to develop new products". Should this include an effort to more highly
define the indication for treatment with hormones. There are various reasons bone density may be
low. One of them certainly is low
estrogen but should we be working people up with hormone measures at baseline
at least initially in more studies and potentially clinically?
The
converse of course since this is a well existed literature and I've just cited
one article which is compatible with the notion that the increase in breast
cancer after menopause is very related to the increased BMI and there's a large
literature relating this to the increased production of endogenous
estrogen. So then one would say that
giving more estrogen to someone who already has enough might not be a wise
idea. Those are really my only
contributions I hope to this meeting.
I
will make a very brief comment about the WHIMS study, only to mention that
there is some indication that endogenous estradiol estrogen in women is related
to the risk of vascular dementia.
Cerebrovascular changes are recognized as contributing to Alzheimer's
Disease ("AD"). This is
discussed by Dr. Schumaker in the WHIMS paper and also by Dr. Katz who might
comment if needed on the specific review of the WHIMS trial by the FDA. Lastly in an autopsy study, it was found that
vascular changes in the absence of AD were present in patients with histories
of dementia.
I
put this together to say that vascular disease may be contributing more here than
immediately apparent. That's important
because if we tailor the doses of estrogen and the doses and types of
progestin, we'll more likely be able to control any contribution of exogenous
treatment to vascular disease than to other types of dementia. Thank you.
CHAIRMAN
McCLUNG: All right. Thank you.
Questions or comments or clarifications for Dr. Stadel from us? If not, let me suggest that we take a 15
minute break and to be back at 3:05 p.m.
We will embark upon our deliberation among ourselves. Thank you.
Off the record.
(Whereupon, the
foregoing matter went off the record at 2:50 p.m. and went back on the record
at 3:10 p.m.)
CHAIRMAN
McCLUNG: On the record. So we have completed the formal presentations
by those who were invited or who asked to be a part of the presentation. The remainder of the meeting will be focused
on a discussion among the Committee members to share ideas with each other and
to address some of the specific issues that were posed to us by the FDA.
We're
happy to have the audience stay but there won't be the opportunity for audience
members to make comments or presentations unless we, the Committee, have some
specific issues of clarification from either the WHI group or the group from
Wyeth. To start this session, let me
invite Dr. Orloff to make comments again and to provide us our charge.
DR.
ORLOFF: First of all, I see that most of
the WHI team has departed. I want to
thank the doctors who are staying and make sure that you all thank the rest of
the group for their input. I guess I
should also comment that never let it be said that we "slow-pitch"
our advisory committee. This is an
extremely complex issue. Also let it
never be said that the FDA's job is an easy one. And with that, charge. No.
This
has truly been a fascinating day and a unique one in bringing together the
group of investigators of a landmark trial and obviously an extremely important
and high profile public health area to present face-to-face the results,
up-to-the minute and on-going plans for their study to our Advisory Committee
and to have interested public as well as the particular interested
pharmaceutical sponsor, the most interested perhaps be here to comment as well.
We
have really two central issues that we'd like to hear more comment on. The first one relates to essentially your
satisfaction, your consideration of the accuracy and appropriateness and
completeness of the labeling changes that have been made to the labeling for
this class of drugs after the WHI. By
and large, the discussions on both sides up to this point, by the WHI group and
by Wyeth, pretty much inform directly your discussion on that issue. So we really need some more direct
input. That might go fairly quickly I
would anticipate.
The
other one is a much more complicated issue.
That has to do with the true intent of the meeting which is the
implications of the WHI and its results for the future vis _ vis this class of
drugs particularly related to the clinical development of these drugs for use
in post menopausal women. What we're
asking for is some comments on everything from endpoints to inclusion criteria
to duration of trials to size of trials to whatever else you may want to
speculate on. I'll leave it at
that. Thank you.
CHAIRMAN
McCLUNG: Thank you. And I propose that we deal with those in
order. So let me ask the Committee to
share with me your thoughts and comments about the first issue which was your
feelings about the revisions and the current prescribing information for
Prempro that's been provided to us and has been presented today. Are there specific comments to make about
that?
DR.
SCHAMBELAN: I could continue the
baseball metaphor. Unfortunately the
people in the San Francisco Bay area got used to fast pitch baseball the last
weekend and so I guess I don't have to watch much more television for the next
couple of weeks.
The
question I had about the prescribing information really focuses on a point that
was raised just before our break and actually directed to folks at Wyeth about
the subtlety of the language in point three under indications and usage about
the careful consideration of non-estrogen medications versus a requirement that
another medication be tried. I'm not
sure that I have a specific recommendation to make, but it seems to me of all
the recommendations I've seen here that's the one that strikes me where we need
the greatest amount of thought.
I
come from the land of Grady and Cummings and Holly and Black and this has been
discussed obviously since the HERS and WHI trials have come out. The focus of these individuals has been to
recommend other therapies before and this is in an asymptomatic patient we're
talking about now which would be presumably point number three for the
prevention of post menopausal osteoporosis.
From my point of view in terms of recommendations, that's where this
discussion could best go.
CHAIRMAN
McCLUNG: Dr. Bone.
DR.
BONE: Thank you. We certainly want to commend the
investigators for managing an enormous amount of information. Their forthright recognition that the
osteoporosis related questions were fairly far down the list in the
considerations of the study design. We
have to recognize the challenges to the FDA in calculating things like risk/benefit
balance from a regulatory standpoint when we are dealing with information that
wouldn't really be considered - I don't mean this with any disrespect at all
for the work that was done - an adequate and well controlled trial for the
indication, prevention or treatment of osteoporosis.
The
patients weren't selected on the basis of their risk for those conditions. The endpoints that were measured were
fracture but we don't have comprehensive bone density data. We don't have turnover markers. We don't have a lot of the information that
we would want to use to relate the risks and benefits. We have a risk scale which appears to give a
relatively shallow gradient between the highest and lowest tertile. But with that gradient, it looks as though
most of the disadvantage to being treated is abolished in patients who have
somewhat higher risk of developing an osteoporoic fracture.
I
actually think that the Agency has done a good job of incorporating this
information and the company into the current labeling. It's going to be difficult to improve on this
very much without having the kind of more precise estimates of effectiveness
for one thing that we would drive in a purpose-built trial. We're getting to the point where we're
pushing it pretty hard to try to see more than has been said with some possibility of some nuances.
The
suggestion that a twofold increase in the risk of fracture is somewhere near
the breakeven point which is tantalizing as something that might be
incorporated into labeling but I think it's pretty soft. I'm not sure that I could make that
recommendation. I really think that when
we start looking at the limitations of the way in which this enormous
undertaking specifically addresses the questions that we're dealing with, I'm
not sure we can add a great deal.
CHAIRMAN
McCLUNG: Other comments? Dr. Follman.
DR.
FOLLMAN: Yes, I have a question about
the labeling. It's more my ignorance of
this area. But there's this one phrase
"should be prescribed at the lowest effective dose for the shortest
possible period to achieve treatment goals." I wondered what "achieving treatment
goals" means for osteoporosis. Does
it mean that you have a target-free BMD and you try and achieve that target and
so it sounds like the therapy could go on forever. I don't know what are the treatment goals for
using this for osteoporosis. I think if
I understood that better I'd have a better handle on what the duration might be
and other points.
DR.
ROSEN: Mike, can I comment?
CHAIRMAN
McCLUNG: Sure.
DR.
ROSEN: Yes, I think that's the problem
in clinical practice. I think we don't
have good endpoints. We use bone density
as a surrogate marker but I'm not so sure that it's the endpoint that we should
be looking at. We have women that
fracture on estrogen whose bone density goes up. That clearly can be misleading and that's a
big part of the problem.
When
we're talking about the indication labeling here particularly for prevention
which has to be highlighted not treatment of osteoporosis where we have
endpoints such as fracture, we're in a real gray zone in terms of what
prevention outcomes should be. Should it
just be bone density? Well, 40 percent
of women taking calcium and vitamin D will maintain their BMD two or three
years after menopause. This is a real
gray area that we haven't established in our "osteopenic population"
and that's what makes it very difficult for you as well as for us who are
dealing with it on a regular basis.
DR.
BONE: Could I just respond to that?
CHAIRMAN
McCLUNG: Yes, Dr. Bone.
DR.
BONE: One of the things here is when
we're talking about prevention "Do we mean stabilization of osteopenia or
do we just mean prevention of any loss whatsoever?" We could argue
that a person whose T-scores averaged plus one who took a drug and didn't drop
over the next 20 years had prevention of osteoporosis. And she might have, but another way to look
at this is to identify a patient with increased risk of developing osteoporosis
and then modify that risk in some measurable way. Maybe that's something that we should be
clarifying.
I
don't think that's something that is a response of the Agency in the labeling
of this particular medication in response to this particular set of information
but as a general approach that bears on the next question of going
forward. How we understand ourselves to
be preventing osteoporosis or preventing post menopausal bone loss and how
those two slightly different objectives interrelate is going to have tremendous
implication especially for issue like risk/benefit analysis.
CHAIRMAN
McCLUNG: My personal view about the
labeling and indications is that of Dr. Bone.
It's truly hard to get better than we are. The issue of what the endpoint is for
prevention is well taken. While we know
that bone density is a very powerful predictor of fracture risk in untreated
patients, the relationship between the magnitude of the change in bone density
in response to any therapeutic intervention and the reduction of fracture risk
is less well defined. So it is a
hypothetical model in our head as we imagine that if we preserve bone mass and
prevent the loss of bone architecture and the deterioration of bone quality
that it would make things be better. But
those aren't measurable endpoints or outcomes.
The
issue about what to do with non-estrogen medications and whether they should be
used first or recommended first is more difficult in my view for two
reasons. One is the WHI has given us
this huge set of information with a very large clinical trial of 16,000 women
followed for five years. So we have
80,000 patient years to deal with. No
other osteoporosis alternative, non-estrogen alternative, be it a SERM or
bisphosphonates has that kind of information.
While we are more confident about the risks associated with longer term
estrogen use, I personally am less confident about the risk profile of long
term use of these other agents too. So
we're not quite comparing apples and apples in that regard.
Lastly
if we require that somebody be treated with another drug first and then fail,
the definition of failure of therapy is an unknown issue too. Having a fracture on bisphosphonate therapy
or raloxifene therapy or estrogen therapy isn't evidence of treatment failure
because the drugs don't cure osteoporosis. They just reduce risk. The absence of fracture doesn't mean that the drugs are
effective so we don't have a way to decide whether a patient has failed on
therapy or not which would make it even more confusing from a clinical
standpoint.
So
from an indication standpoint, my personal view is that the changes that have
been made of clarifying that the use of Prempro is for the prevention of
osteoporosis, not for the treatment of osteoporosis was helpful. That it was recommended only for women at
significant risk. Trying to define that
risk more specifically in the context of a label is really difficult and that's
not been imposed upon any other therapy for osteoporosis. That the reminder that there are alternatives
now for the prevention of bone loss is included in the statement already. That's made great progress with the changes
that have been made this past year. Dr.
Bone.
DR.
BONE: Actually one comment that was made
by Dr. Colman I think was kind of provocative.
That was if we were in a better position to assess the risk/benefit
relationship some of the newer data showing a reduction in hip fracture would
actually support even a specific treatment indication.
But
the problem as pointed out by a number of the WHI group is that we don't have the analysis at least at
the moment to look at things like the effect on cognition in the same
population that's at the highest risk for fracture. So we come back to the point I was making
earlier about trying to go from an all-purpose trial to a very specific kind of
information. This is one of the places
where I'm not sure we can make that step.
CHAIRMAN
McCLUNG: Other comments about the
current labeling issue? Dr. Woolf.
DR.
WOOLF: I personally like the wording on
the third bullet point. Clearly
physicians need to know what their options are.
While clinical trials are meant to give us population risk, what is the
appropriate treatment for a woman with significant breast family history and
coronary artery disease clearly may be very different than somebody who has no
family history of breast cancer and no family history of coronary artery
disease and who has some vague GI problems.
This gives sufficient information to physicians to take all these
individual things into account and decide what treatment is best for the
patient for osteoporosis.
CHAIRMAN
McCLUNG: There are indications for
therapy but the indications are like this.
They are indications for diseases and for problems in general. They don't usually define how that diagnosis
is made which gets to the point of trying to attempt to define which patient
would be the candidate for in this case estrogen/progestin therapy. This is not what's usually done in the way
we're given information as clinicians about that. Is my assessment correct?
DR.
ORLOFF: I think your assessment is
correct. You know the hardest part about
labeling a drug is to ?- Put it this way. We can never
expect or even hope to fully direct the practice of medicine via a drug label
nor do we think that it's a good thing.
As has been stated many times, the practice of medicine although we like
it to be evidence-based and as Dr. Anderson has said particularly in the area
of prevention that has to be based upon population studies. Nevertheless when we do take care of
patients, it's one-on-one.
That
said, the purpose of the label is to convey throughout the extent of the label
with a particular focus within the indications and usage section that
information on expected benefits and risks within the context of use in the
proposed target population. We wind up hedging a lot and the way we structure these indications fall short for
example of using the term "second line therapy" but logic directs
that the intent here is that the only primary indication for this use of this
product at this point is for the treatment of vasomotor symptoms because as has
been stated here I guess here and elsewhere that this is really the only viable
therapy for that aspect of the post menopausal condition in women. We go on to say then as is clear that if you
are treating because you want to direct an intervention towards the other known
expected benefits of in this case estrogen plus progestin, think about what
your other options are because on balance, we cannot tell you across the board
that you can expect benefits that outweigh risks.
CHAIRMAN
McCLUNG: Dr. Schade.
DR.
SCHADE: I may be the only one who
doesn't like this labeling. I'm
convinced that everybody at this table who sees patients and I see patients
would make the right choice. What
bothers me is many physicians at least at my institution wouldn't have the
background and knowledge of this whole trial and hear this type of discussion.
I
actually think point number three here where we're talking about prevention of
post menopausal osteoporosis doesn't really help the physician enough. In other words, the minimum I would do is to
extend the last sentence where it says "When prescribing solely for the
prevention of post menopausal osteoporosis, therapy should only be considered
for women at significant risk for osteoporosis and non-estrogen medications
should be carefully considered." I
would add something to the nature that "particularly in patients with a
family history of breast cancer, with cardiovascular disease," etc. The things that we're worried about.
I
would simply extend that sentence to be more helpful to the general
practitioner who hasn't heard a day long discussion of the WHI. I think that this is not specific or detailed
enough to be very helpful.
CHAIRMAN
McCLUNG: Dr. Lukert.
DR.
LUKERT: But do we really know that the
people who are most likely to have these adverse effects when given estrogen
were people with a family history and the other risk factors? It was my understanding that it really wasn't
the case. Maybe it wouldn't be accurate
to say that we could limit this to worry about the people who had these
particular risk factors. It seems to me
that this insert adequately -- anyone who reads it ?- If they don't read it, there's
nothing that we can do about it. But a
physician or patient who reads this - in my experience, the patients read them
rather consistently ? the dangers are going to be emphasized to them and they are going to
understand that this is a drug with considerable risk as well as benefits. I think it's fairly well balanced in that
regard. I'm not sure that we will be
giving them accurate information if we add those risk factors. I'm not sure that increasing their
susceptibility is the adverse effect in response to estrogen although we would
expect it to be global.
DR.
ORLOFF: I want to make a quick comment
if I might of clarification.
CHAIRMAN
McCLUNG: Yes.
DR.
ORLOFF: Because I do agree with Dr.
Lukert. Unfortunately drug labels are
long and they must be read to be understood.
That's a whole other discussion.
But as I said the label in toto addresses expected benefits and risks
when used in the proposed target population.
By and large, the indications reflect expected benefits. Elsewhere in the label you see the risks and
indeed in the sections directly following indications, there are
contraindications which are the strongest recommendations against the use of
the drug for safety reasons. Then those
are followed by warnings and by precautions.
Based
upon the results of the WHI, the warnings and precautions sections of this
label have been changed to add additional information about the overall risks
of the product. And those risks need to
be taken into account when you're sitting across or at the bedside of the
individual patient and making the consideration about on the one hand whether
their risk for osteoporosis which isn't something you read from this label, but
whether they're at risk for any of the known potential adverse effects of this
drug that your gestalt would alter your impression of the overall balance of
risk and benefit.
CHAIRMAN
McCLUNG: Mr. Follman.
DR.
FOLLMAN: I'd like to talk about the
table on page 18 of the insert which goes into the relative and absolute risks
for the various events comprising global index.
I actually like this with displaying the data. I thought it laid it out in a lot of its
complexity. It showed the pros and
cons. The relative risk numbers are
useful to the population and would be appropriate here in that we usually in
clinical trials think the relative risk for the entire study is appropriate for
all subgroups. That feeling has been justified
by all the analyses that were done today where we show that the relative risk
for the most part if not entirely were consistent across the wide variety of
subgroups.
When
you talk about absolute risk though, the story is a little different. The absolute risks in this table are for the
entire WHI cohort. If we're thinking of
osteoporosis specifically, I'm imagining this is going to be prescribed for
women who are at high risk for hip fracture.
If that's the case, then these absolute risks given in this table
probably are too low and don't quite fully reflect the benefit you might get
from hormone replacement therapy.
I
did a little rough calculation based on Dr. Cauley's article where she looked
at the risk of hip fracture as a function of this risk score. She showed that overall the relative risk was
similar but there's a huge gradient in the risk of hip fracture as a function
of this risk score. At the highest
tertile, instead of expecting hip fractures in the placebo group for 10,000
person years, it would be more like 65 and for the estrogen replacement
therapy, it would be more like 45 instead of 10. So instead of a difference of five, it would
be something more like 20. This isn't
actually an exactly correct number because I couldn't do the exact calculation
based on the information in the JAMA article.
But
the larger point is whether we should give more specific information regarding
absolute risks in aiding the decision.
We're trading off risk and benefit here.
We're thinking about absolute risk for each individual decision and more
precise estimates and more tailored to the individual would be helpful.
CHAIRMAN
McCLUNG: My comment about that is that
there are ways that people can find out what absolute risk is. There are a variety of studies that had
helped us to do and there's a move afoot among the osteoporosis and bone density community to
move away from expressing bone density values in terms of T-scores and absolute
values, but rather to express them in terms of absolute risk that incorporates
at least three important dimensions, BMD, age and previous fractures. So determining the absolute risk in an
individual is an important clinical objective.
It's hard to figure out how to do that in the context in my view of a
specific label that is for one particular drug.
That needs to be a part of the educational process that we collectively
engage in to deal with improving the understanding of osteoporosis, its risk
and circumstances across the entire population.
Dr. Bone.
DR.
BONE: Just further to Dr. McClung and
Dr. Follman's comments. If we were truly
going to try to identify a group at what for those of us who make a large part
of our effort in osteoporosis area we consider high risk, first of all, the
risk gradient would be a lot higher than even you're describing. Secondly, we'd be talking about an indication
for the treatment of osteoporosis which is not part of the label. We go around in a circle there because once
we start talking about people with a higher risk of hip fracture, we're talking
about a disease for which the drug isn't actually approved at the moment. I'm not disagreeing with you. I'm just saying it takes us to a strange
place.
CHAIRMAN
McCLUNG: Let me attempt to summarize
then what I sense is a prevailing comment.
Let me see if I can do this in the right way. The current label for the combination
estrogen/progestin that was studied in the WHI has been upgraded and changed
substantially in two separate steps, first on the basis of results from the
HERS trial and then more recently with the results from the WHI data.
The
changes that have been made accurately reflect the information that was provided
to the academic community from those two trials and has put the use of the
medication for the prevention of bone loss and osteoporosis in a different
perspective than existed before. Changes
that have been made have been very useful and positive. Collectively, we can't think of a better way
to express the information than is stated in the third indication that
specifically focuses on the use of Prempro for the prevention of osteoporosis.
We
all recognize that none of this is perfect and this requires understanding in
the background that's in the rest of the package insert that has to do
specifically with the contraindications and the other risks that have been
described and that are outlined in subsequent paragraphs. I personally think that it's not possible to
incorporate all of that information into a succinct paragraph under the
indication and usage circumstance.
With
that, let me propose that we move on to the second issue which let me restate
it. We're asked to discuss the
implications of the WHI trial results for the future development, testing and
potential approval of estrogen plus progestin drugs products for the prevention
and/or treatment of post menopausal osteoporosis. We will expand the discussion beyond what
we've worked on. Who would like to open
that discussion?
DR.
FOLLMAN: I guess one thing that was
talked about consistent with the labeling is lower dose, shorter duration. I can see that there will be movement towards
doing studies like that where you have low dose and you'll look at probably a
surrogate endpoint bone mineral density say and see whether that differs from
placebo or not.
I
worry a little bit about that. This is
consistent with a point that I made earlier that you could show that there's a
difference at a very low dose between placebo and the treatment in terms of
bone mineral density but it might not be efficacious in terms of clinical
endpoints preventing fractures of different types. If you are doing such studies you should
probably be mindful of that and want to have a lowest dose that still gives you
what you guess is a clinically meaningful benefit. By "guess" I guess I mean that you
would use observational data correlating BMD with the probability of fracture
and have some comfort that the difference in BMD would translate into a
clinical benefit. I'm just wary of going
as low as you can.
CHAIRMAN
McCLUNG: Dr. Lukert.
DR.
LUKERT: I think that if you could have
done whatever you thought would be most helpful it would be to look at
transdermal estrogens as opposed to oral because of the effects of the first
pass through the liver, of the effects on coagulation factors and upon the
precursors of angiotensin. Those all
have such vascular implications plus the effect on growth factors produced by
the liver and the potential implications on those. One of our areas of investigation should be
other forms of delivery.
As
far as the implications are concerned, I'm just delighted when I see a patient
come in with such profound vasomotor systems that she has to be treated with
estrogen. I know that at the same time
that this will give us some time to improve her bone metabolism while we're
waiting for her get over her vasomotor symptoms. Otherwise, we're ethically on sort of shaky
ground given the data we have with evidence based medicine to use estrogen as a
primary form of treatment or prevention of osteoporosis.
CHAIRMAN
McCLUNG: Dr. Woolf.
DR.
WOOLF: I think if we learn anything from
HERS and WHI it's that we need hard endpoints and not surrogate endpoints. Any future estrogen trial have hard
endpoints, fracture data, current and adverse events and we can't use surrogate
endpoints because they led us astray for God knows how long. They'll make these trials very long and make
them complex and make them expensive.
But I don't see any alterative.
DR.
BONE: Can I just respond to one point?
CHAIRMAN
McCLUNG: Sure. Dr. Bone.
DR.
BONE: I think if we look at the
indication treatment of osteoporosis that's one point. But if we're talking
about prevention of osteoporosis, we're talking about starting with a patient
population at a very low risk of having a fracture in which we hope to see that
the risk does not increase. It becomes a
prohibitive problem to try to see a difference in fracture rate in the
prevention indication. That's the
subject of a lot of discussion and writing as you know. It's the reason why the endpoints are what
they are in the current guidance as to use of bone density to show prevention
of post menopausal bone loss. The
distinction there is between treatment of osteoporosis and prevention of post
menopausal bone loss.
CHAIRMAN
McCLUNG: Dr. Woolf, you're going to
respond to that.
DR.
WOOLF: I agree but these other endpoints
are going to take some time and the adverse events. Typically the prevention trials have been two
to three years and these other things are going to five or six years to develop
which may give you enough time for those factors. The WHI also showed us that these are very
potent drugs to prevent fractures. The
question is can we leverage in future years to come up with a dose of estrogen
and delivery system for estrogen that gives us the bone benefits without the
cardiovascular and CNS detriments. The
only way to do that is time and obviously enough patients, but some of the
bisphosphonate trials were three or four thousand patients so they are getting
up there.
CHAIRMAN
McCLUNG: Nine thousand patients.
DR.
WOOLF: Even better.
CHAIRMAN
McCLUNG: Right.
DR.
CARPENTER: I can only echo the comments
made by Barbara and others to pursue for future investigation both dose and
delivery mechanisms. I think weighing
risk and benefit in the lower doses is clearly an important strategy and one
that in fact with the data coming in through post marketing would be highly
encouraged to aggressively collect already at this point in time. I also would being in the role of a
pediatrician having to use many drugs off-label and look at other situations in
which these medications are used perhaps on but also off-label and that is the
life-long effects of using these medications in women with premature ovarian
failure for various reasons and that data is a smaller set but clearly everyone
is applying data from studies such as WHI and others that we've heard about
today extrapolating it to long term use.
I think we really don't have that data.
It's an important area to pursue.
CHAIRMAN
McCLUNG: Dr. Rosen.
DR.
ROSEN: Thank you. One of the areas that I feel uncomfortable
about in practice and also in research is predicting who is going to go on to
sustain rapid bone loss. This is an area
although we use bone density as a marker, we don't have the large scale trials to actually tell us what the
predictive factors are. So if you knew a
woman who walked in at 50 with a T-score of -1 was not likely to lose a lot of
bone versus somebody who walked in and they only had a five percent bone loss
as Claus has shown that some subpopulations do have those rapid rates of bone
loss, those are clearly individuals that might be targeted for short-term, low
dose therapy.
The
truth of the matter is the markers have not done a very good job certainly not
in practice of predicting that. We're
getting to an era now where it's open for the NIH and other non-commercial
entities to consider supporting this kind of investigation looking at
proteomics, trying to predict through protein markers what are the factors in
post menopausal women that might potentially predict their subsequent rate of
loss or fracture as well as genetic studies which are just starting to do in
WHI.
This
is an area of investigation that we still don't have a real good handle on and
I'm afraid in clinical practice we have a very poor handle on it. We use bone density, T-scores of -1, but how
that translates into those people five years down the road still is
problematic. That's an area that we
really would need tied to possibly to a prevention trial with our surrogate
markers. It's going to be impossible to
do a fracture study with young post menopausal women because their absolute
risk of fracture is so low. But we could
use another type of trial to pick up risks of rapid bone loss certainly that is
a surrogate for some aspects of changes in bone quality.
CHAIRMAN
McCLUNG: Right. Just to comment, there are some data about
that. In the EPI trial for example with
the large population, the only two things that we've been able to demonstrate
predicated rates of bone loss were body size and how close they were to
menopause. The distribution of the rates
of loss was actually amazingly tight.
There weren't a big subset of fast losers and other who didn't lose at
all. It was tightly grouped about that.
Of
course, that applies not just to this drug but to any choice of therapeutic
intervention for prevention. So defining
who the person is to initiate pharmacologic intervention is a general question
that the clinical community is still grappling with and which individual would
be candidate for estrogen as opposed to an alternative is a subquestion under
that big umbrella.
DR.
ROSEN: Sorry, Mike. I just wanted to add that part of the problem
may be that we don't have the right markers yet to predict that. That's an area of active investigation that
we should consider. There are a couple
of different new markers coming out or need to be explored and those are the
kind of investigations we need to take up.
CHAIRMAN
McCLUNG: Sure. Dr. Bone.
DR.
BONE: One of the things that we normally
do as endocrinologists is try to achieve very consistent and precise control of
the level of whatever hormone it is that we're administering. I'm not sure we've done as much about that in
this area as we could have. Dr.
Lukert's, Dr. Rosen's and Dr. Stadel's comments all make the point that first
of all some of the earlier studies that were done looking at the serum
estradiol levels required to stabilize bone mass might be revisited with more
sensitive testing to see if much of the benefit could be achieved at somewhat
lower serum estradiol levels.
Selby's
paper looked like something like 45
picograms per mL or something seemed to be effective in just about
everyone. There may be some individual
interactions that could be in part genetically determined on that basis. Maybe there's a group that requires a lower
dose where 14 picograms per mL of estradiol is just fine depending on what the
SHBG is or something.
But
this is what endocrinologists do. This
is more challenging in the case of CEE because this is a mixture of the
ingredients each of which is going to be metabolized differently. I don't think I can add anything to the
discussion that Dr. Woodcock gave last year at the NIH meeting on it where she
discussed this whole topic fairly thoroughly, but the point being that it's
more complicated with CEE. If we were
talking about serum estradiol or could pick out what it is and we really had to
be concerned with and then could thread the therapeutic needle so to speak, we
might find ourselves able to be on the right place on dose response curve for a
desirable effect with getting too far up the adverse effect curve.
I
suspect that the dose response curve is somewhat plateau-shaped as is usually
the case. And that is as often the case,
the adverse event curve may not be. We
may find that really understanding the endocrinology of post menopausal women
better and what our targets are that we should be trying to achieve in order to
mitigate this rate of loss could really put us into a more elegant, more
endocrinologic approach to solving some of these problems.
CHAIRMAN
McCLUNG: Other comments? Let me add a couple of my own. The question of what these implications are
for the development of other estrogen/progestin products for osteoporosis
management, both prevention and treatment, really is broken down into at least
three discrete categories. We met a year
ago to review the guidelines again about the prevention and treatment
indications in the guidance and the types of trials, the types of endpoints
that were there.
Those
guidance points have served us I think extremely well for the last ten years or
so. The distinction of preventing bone
loss in low risk populations with bone density as the primary endpoint still
makes good sense until we've had some other better determinant of bone strength
and bone architecture and bone quality.
As we develop new imaging studies and new techniques, we may move away
from simple bone density to the more sophisticated endpoints. To require fracture as an endpoint in studies
where the idea is simply to prevent and stabilize the skeleton will be beyond
the scope of what anyone can do.
For
the treatment indication, we all agree that surrogate endpoints aren't
sufficient and that documenting fracture risk is necessary to do that. Those are already embodied and codified in
the current guidelines. Whether we are
talking about estrogen/progestin drugs, estrogen only drugs, different routes
of administration, different doses, non-estrogens, all those still fall under
that same rubric.
The
major issue or another issue though that makes estrogens be unique is their
risk profile and dealing with evaluating whether different doses, different
preparations, different routes of administration have differences in risks is a
different both investigative and certainly a different clinical question to
address and may take a great deal longer time to do. It may not be practical to include in one
study particularly if we're talking about prevention indications the efficacy
endpoints on the one hand and the entirety of the safety endpoints that one
would like to see and to demand.
There
are already in the current label for this preparation and now expanded to the
other estrogen preparations the concerns and statements about risks that are
extrapolated from the WHI. My thought is
that for a drug to be approved for the prevention of osteoporosis it could
still get there by the same route to be distinguished as being different in
terms of its risk profile could be addressed in a separate question.
For
an estrogen or an estrogen/progestin preparation to be assumed to be in the
same category is maybe the most straightforward or the most sound place to
start and require that drugs do the studies
to distinguish themselves from the risks that are embodied in the
WHI. That would be a different type of
study that would change the contraindications and/or the risks but wouldn't
change the indication.
The
third piece of that is that it would be really helpful if we could work at
identifying the right people, the ones at risk and whether it's estradiol
levels or whether it's biochemical markers or new markers or whether it's some
other combination of risk factors. It's
a project probably beyond the scope of the FDA or the sponsors of studies that
are submitted to the FDA but is an NIH and/or some other global approach to
things. Dr. Lukert.
DR.
LUKERT: I really like the way you sorted
out the issues. But I do wonder. It seems to me that the major question now
though about estrogen/progestin is are there risks. We know that they do work to protect against
bone loss. So I guess the thing I would
question is whether we really need any other new estrogen product if we need to
just assess its effect on bone. It seems
to me that even the greater need is to look at the risks. That would be my only difference.
CHAIRMAN
McCLUNG: Yes.
DR.
ORLOFF: If I might.
CHAIRMAN
McCLUNG: Yes. Dr. Orloff.
DR.
ORLOFF: This is a question that can't be
resolved in the abstract. Some day the
data will have to be produced. What we
would probably conclude from this discussion is that the burden is on the
proposer and on the community involved in this field to produce a weight of
evidence that supports a favorable risk/benefit profile say for example for an
estrogen or estrogen/progestin administered by an alterative route or for a
lower dose of estrogen alone or estrogen plus progestin. That risk/benefit profile would thereby be
distinguished from the dose and product and route of administration that was
studied in the WHI. There's been a lot
of speculation today based upon one or another subgroup analysis of the WHI
despite cautions about inferences from those analyses that there may be reason
to believe that the risk/benefit profile for Prempro for example might be
different in one group versus another for example by age. Those are interesting speculations but I
don't think we have any data from this trial to bring to bear on it.
I
would say that we spent a lot of time today talking about the global index in
the WHI. I'm not sure that there was any
complete agreement on what the role of the global index was after the
fact. But for a new product coming
along, we would be hard pressed to from the start ask for essentially the same
quality of hard data, to ask for a global index score, for a new product. We would expect sponsors to propose a data
package that would be perhaps more traditional harkening back to the usual way
in which we evaluate drugs that someone referred to here earlier which is that
we design trials to establish the benefit based upon our hypothesis and then we
look at the safety profile and we make some judgment as to whether we think it
satisfactorily safe given the benefits.
We use our heads on this.
In
this particular instance, we would use our heads as Dr. Bone has suggested that
clearly there's every reason to believe that as you reduce the dose the risks
associated or at least some of the risks associated with the use of such a
product are also going to be reduced. So
also are the benefits, but we have to understand that the benefits of such an
intervention are monitorable.
We
go into this with an assumption that particular for estrogen there is a graded
and continuous relationship albeit not perfect from patient to patient but
there is a graded and continuous relationship between bone mineral density and
fracture risk. It comes from
epidemiology. It comes from
intervention. So we believe in BMD and
in practice one can monitor BMD to assess whether an individual patient has
responded to the dose, route of administration and particular molecular species
with which she is being treated.
That's
by way of saying that ultimately we'll know when we know. I don't think that I've heard here a
consensus and correct me if I'm wrong that we absolutely are looking towards a
day when no estrogen or estrogen/progestin could possibly come to market for
the management for post menopausal bone loss in the absence of a WHI type
study.
CHAIRMAN
McCLUNG: Comments about that? Dr. Bone.
DR.
BONE: Yes. Broadening out a little bit from that comment
from Dr. Orloff and little bit where we are, we are basically faced with class
labeling based on CEE and medroxyprogesterone acetate. We faced with some uncertainty about the
whole issue of generalization that's been to other compounds in these general
categories that people have discussed a lot about, not so much today, but at
other times. These variations include
the molecular species, the dose and the route of administration and so forth as
has been mentioned.
What
Dr. Orloff's comments lead us to is the question of how could a sponsor proceed
or how could even an independent organization proceed to try to investigate
some of these questions and have this reflected in the labeling of the drug
product. It seems to me that it would be
extremely difficult for the division to do away with the class labeling all
together in the absence of a study of at least comparable rigor. It might not be such a big study because it
could be more focused so that's a fair point.
But it would have to be a very large, very well designed study to
supercede with some other molecular species for example what class labeling we
seem to be developing.
On
the other hand, does this make this hopeless?
Could it not be the case that to the extent that a treatment, a
medication or a combination that was proposed within the overall umbrella of
the class labeling distinguish itself in some meaningful way by well-documented
data that could be incorporated into the clinical pharmacology section of the
labeling? The sponsor then would
basically be able to say "Yes, we're operating within this WHI class
labeling but we've been able to show that at least one element of this is
somewhat different or may well be or something like that."
It
seems to me that the clinical pharmacology section may be one place for this
and that could result in more nuanced warnings and precautions if the data are
there without disrupting everything.
That's a way that a sponsor could proceed in the development of a new
product to say "Okay, we're going to concentrate on what we think are two
to three important things where we really think we can demonstrate an
advantage. Then once we have a toehold
maybe we may go for the big trial."
It's just a way of thinking about that.
I
have to say without wanting to open a can of worms that there's some overlap of
this in the SERM area because of overlapping effects that some of these issues
may arise there as well in terms of how one distinguishes one product from
another and could that be done in clinical pharmacology?
CHAIRMAN
McCLUNG: Okay. Other comments?
DR.
CARPENTER: Just a brief response to the
issue of the global index and its future in potential other trials, it would be
a mistake to entirely discard this notion - and maybe I'm speaking from the
minority point of view here - but I find that particularly in the setting where
an efficacy endpoint is very hard to establish where we're talking about
primarily preventive efforts in whatever endpoint we're looking at. We're generally looking at continuous
variable of reversing a natural phenomenon with a considerable way of other
side effects of this that need to be weighed in some way against the endpoint
that we're looking for.
I
haven't seen anything at least to-date that can integrate this comparison
better than what I've seen today in terms of the global index. So it may actually be a model by which at
least other models could be amplified or modified for other comparisons. I don't think that it's something that I
would discourage as an indicator of where to go with these newer therapies.
DR.
ORLOFF: I wasn't quarreling that for the
purposes of producing or generating definitive information, the global index
didn't have a very important role. All I
was saying is that it would seem at this point a very high bar to place to ask
for that standard of evidence for every new product that comes along.
CHAIRMAN
McCLUNG: Dr. Follman.
DR.
FOLLMAN: I'd like to comment a little
about the global index also. I like it
as a simple understandable way of coming up with a number that traded off risks
and benefits. I would also mention that
I don't see how we can come with a different global index for the WHI or try to
refine it in some way. We know the
results of this study so it would be like doing this study without an endpoint
defined beforehand looking at all the data and all the tests and then trying to
come up with the primary endpoint. It's
basically impossible I think.
There's
a potential refinement of the global health index that I think could be
done. It would be to somehow weight the
different categories. A simple way to do
this would be for each of these events, say breast cancer, hip fracture and so
on, calculate the probability that you'd be dead say in the next five years if
you had one or more of these, separately for each of the events and then
instead of summing up, you just note whether you had one of these events or
not. Then you would calculate for each
woman the probability you'd be dead in the next five years based on whether you
had hip fractures, a stroke and so on.
That might be a way of trading off in some way what's worse, breast
cancer or hip fracture or stroke.
DR.
ORLOFF: I understand that the WHI
investigators considered that approach and figured when all was said and done
that it would just add one more level complexity to their trial, the planning
and implementation that wasn't going to be worth it.
CHAIRMAN
McCLUNG: Plus, it would reward events
that happened late in life. They would
get a higher score because the older you are the less likely you are to be
alive five years from now. There are all
kind of nuances to that. I think we all
agree that the global index was put together again for specific purpose of this
study. We've learned a lot about the
disease processes that were evaluated and the outcomes that were evaluated in
the study and nothing precludes the next study if there ever is a next large
study to prospectively define a modification of that index to include vertebral
fractures or other endpoints that we've now learned are important as a part of
these sorts of things. Dr. Woolf.
DR.
WOOLF: I personally would like to keep
the bar high in the next go-around because we have effective alternative
therapies for osteoporosis that have their own set of baggages. We certainly know a lot about Premarin and
its various forms. Why have a lesser
standard of evidence and a lesser standard of commitment to the next
go-around? Why pretend that we don't
have this information? So I'd like to
keep the bar high.
One
other thing, when first I read this material about a week or so ago, I really
did not like the global index. I thought
it was rather simplistic and everything was equal. In my own mind, they weren't equal and there
were a whole set of things that weren't there that may not have been as
devastating as breast cancer but nevertheless were pretty significant problems.
Over
the course of the day, my opinion has changed because I don't know of a better
alternative. I certainly haven't heard
of one. We did discuss at lunch despite
the Chairman's prohibition about weighting the factors of the global
index. One person's weight may not be
someone else's weight and you'd have a whole set of disagreements about the
weighting. We can use quality-of-life
years or something like that. I don't
know. I got away from that. I guess I came around to the global index and
liked it. Have something like that in
the next go-around.
DR.
ORLOFF: Mike, let me just make one more
comment which is that it's important for the record for everybody to understand
that this is class labeling as Dr. Bone has said. It's class labeling because at this point we
don't have sufficient not to apply in some qualitative if not direct
quantitative way the results of the WHI study to this broad class of
drugs. In the spirit of disclosure which
is what we do in labeling, we tell people what we know either specifically or
broadly about the risks and benefits.
I
want to make clear that I'm not proposing that the bar shouldn't be high in
order to have a drug marketed and promoted as somehow absolutely not carrying
these sorts of potential risks or this overall balance of risk and
benefit. That's not what I'm saying. There's a very high standard evidence and
quite frankly it's a little bit difficult to imagine at this point that we're
going to get there.
That
being said the way we've written this label now as I said before the only true,
first line use of this product is for the treatment of vasomotor symptoms. There is no reason not to encourage I believe
the development of lower dose, alternative routes of administration, estrogen
or estrogen/progestin drug products that would effectively address vasomotor
symptoms and then to study them in order to understand the expected effects on
other aspects of the post menopausal woman's health and particularly their bone
health. It doesn't mean that we would
alter the way we write this label. It's
just that we would have something else in the armamentarium to go to in lieu of
higher dose perhaps orally administrated agents for example not to pass any
judgment.
CHAIRMAN
McCLUNG: Dr. Zerbe, do you have a
question or comment?
DR.
ZERBE: Actually all the points have been
very well made and I don't have a lot to add except that the whole effort is to
be applauded in terms of the data that were generated. There really does need to be caution with
regard to general application. I guess
that's a statement of the obvious. From
an industry perspective, we need to be cautious about the bar which certainly
does need to be high, but we do need to also balance that against bringing new
products forward to actually replace some of the products that do have the
flaws. That would be the only thing that
I would say. Thanks.
CHAIRMAN
McCLUNG: Dr. Woolf.
DR.
WOOLF: Speaking of bars now, there is
one area where the bar is incredibly low.
In fact, I think it's below ground.
That's the whole notion of phytoestrogens and natural estrogens that my
patients are coming in with. We don't
have to worry about cancer. This is a
natural product here. It will cure my
bones. It will prevent osteoporosis. I understand the FDA's dilemma on this, but
this has really become a problem bordering on becoming a nightmare. Somehow or other we're going to have to get a
handle on this. I have no idea of what
it would take, but this notion that this is natural and no data either
efficacious or safe. We have to get a
handle on that.
CHAIRMAN
McCLUNG: I'm glad that wasn't today's
issue but we'll be happy to have you volunteer to be the chair of that
committee.
DR.
ORLOFF: Let me get right back to you on
that one.
CHAIRMAN
McCLUNG: That's right. Exactly.
Other comments or issues? Let me
if I can make again try to make some generality out of this. If what I say doesn't resinate with what
somebody else thinks the group said, we can modify it. To address the issue that we were handed about
the implications about the WHO for the future development, testing and approval
for estrogen/progestin products for the prevention and treatment of
osteoporosis, I have heard this. The
current requirements for the approval of an estrogen/progestin product or an
estrogen product for the prevention of osteoporosis is based on sound reasoning
and there seems not to be a need or a big statement to change the guidelines or
requirements for approval for prevention of bone loss.
With
that approval however comes the class labeling of the risks that are already a
part of the estrogen/progestin, estrogen labeling process. For a new product to be able to distinguish
itself as being somehow unique and different in terms of the risk profile, a
specific study that wouldn't necessarily have to address all of the risks
simultaneously but could address a risk one at a time as Dr. Bone could be
done. Then were that data reviewed, then
it could be incorporated somewhere in the package labeling to reflect that the
comparison had been made and that perhaps a uniqueness for that particular
product could be done. But the absence of
that, the concerns about the risks that we already have before us with estrogen
and progestin would not be able to be escaped.
Does anybody want to work on that harder?
DR.
ORLOFF: With the caveat that comparative
safety claims, even implied ones, are difficult to come by.
CHAIRMAN
McCLUNG: Sure.
DR.
BONE: Could I just add one thing?
CHAIRMAN
McCLUNG: Yes.
DR.
BONE: One thing that would be extremely
helpful here is if we can obtain more informative research about the possible
distinctions that have been hinted at in a literature between for example
different progestins and how they might interact with the risk of breast cancer
and that kind of thing. This is an area
not simply for large scale clinical trials but also for really intensive and
well-designed preclinical studies that could inform us in these areas.
CHAIRMAN
McCLUNG: Another point that I reflect on
and would just bring back that was made two or three times was that studying
the population of subjects for whom either the sponsor or the clinical
community thinks that a drug would be most applicable for would be
helpful. We've talked about that there
are different categories of risk or the different individual patients have
different risk profiles and perhaps to encourage studies to be done where the
clinical profiles are predefined and specific groups of patients be targeted
for evaluation. This would another thing
to come out of the discussions that we've had today.
The
third issue was the broadest of all and was a time if there were comments
beyond what we've already dealt with to make to Dr. Orloff and his team about
outcomes from the WHI trial and how it relates to the issue of approval for
osteoporosis indications for estrogen and progestin therapy. Any other comments? Now is the time to add that to the discussion
here.
DR.
ORLOFF: Dr. Woolf already got his other
comment in.
CHAIRMAN
McCLUNG: Right.
DR.
WOOLF: I expect a phone call.
CHAIRMAN
McCLUNG: All right. With that, Dr.
Orloff, we have exhausted our thoughts about this and hope that we've provided
some input that you and your group can deal with over the next time here.
DR.
ORLOFF: Again, thank you everybody for
giving up your valuable time. We much
appreciate it and we'll take it from here.
Thank you. Off the record.
(Whereupon, the
above-entitled matter was concluded at 4:26 p.m.)