1
DEPARTMENT OF HEALTH AND HUMAN
SERVICES
FOOD AND DRUG
ADMINISTRATION
CENTER FOR DRUG EVALUATION AND
RESEARCH
PERIPHERAL AND CENTRAL NERVOUS SYSTEM DRUGS
ADVISORY COMMITTEE
NDA21-645, MT 100, (naproxen
sodium
and metoclopramide
hydrochloride)
Tablets, Pozen, Inc. for the
proposed
indication of acute treatment
of migraine
headache with or without
aura
Thursday, August 4,
2004
8:00 a.m.
Advisors and Consultants Staff
Conference Room
5630 Fishers Lane
Rockville, Maryland
2
PARTICIPANTS
Karl Kieburtz, M.D., MPH, Acting Chair
Anuja Patel, MPH, Executive Secretary
MEMBERS
Michael D. Hughes, Ph.D.
Carol L. Koski, M.D.
Roger J. Porter, M.D., (Industry Rep,
Non-Voting)
Ralph L. Sacco, M.D., M.S.
SPECIAL GOVERNMENT EMPLOYEES (VOTING)
Larry B. Goldstein, M.D.
Lily K. Jung, M.D., MMM (Acting Consumer
Rep)
Stanley Fahn, M.D.
Marc E. Lenaerts, M.D.
K. Michael Welch, M.B., Ch.B., FRCP
Sheila Weiss-Smith, Ph.D., FISPE
Mark W. Green, M.D.
FEDERAL GOVERNMENT EMPLOYEE CONSULTANT
(Voting)
Dilip V. Jeste, M.D.
FDA
Robert Temple, M.D.
Russell Katz, M.D.
Eric Bastings, M.D.
Mary Ross Southworth, Pharm.D.
3
C O N T E N T S
PAGE
Call to Order and Opening Remarks:
Karl Kieburtz, M.D., MPH 5
Anuja Patel, MPH
Conflict of Interest Statement:
Mary Ann Killian 7
Overview of Issues:
Russell Katz, M.D. 17
Sponsor Presentation, Pozen
Incorporated
Introduction and Summary:
Marshall E. Reese, Ph.D. 24
Overview of Tardive Dyskinesia:
A.H.V. (Tony) Schapira,
M.D. 35
Review of MT100 Efficacy:
William James Alexander, M.D.,
MPH, FACP 61
Potential Role of MT100 in Migraine
Therapy:
Balancing Benefits and Risks:
David B. Matchar, M.D.,
FACP 78
Clinical Considerations on Migraine
Treatment:
Stephen D. Silberstein,
M.D. 99
FDA Presentation
FDA Risk/Benefit Considerations:
Eric Bastings, M.D. 108
Overview of Tardive Dyskinesia:
Hyder A. Jinnah, M.D.,
Ph.D. 127
Post-marketing Review of Movement
Disorders
and Neuroleptic Malignant Syndrome
Associated
with Metoclopramide:
Mary Ross Southworth,
Pharm.D. 138
Questions from the Committee to the
Sponsor
and to FDA
160
4
C O N T E N T S
PAGE
Open Public Hearing
Cynthia McCormick, M.D. 217
Committee Discussion and Response to FDA
Questions 225
5
P R O C E E D I N G S
Call to Order and Opening
Remarks
DR. KIEBURTZ: Good morning.
This is the
Peripheral and Central Nervous System
Drugs
Advisory Committee. We here to discuss the New
Drug Application 21-645, proposed trade
name of
MT100 Tablets, from Pozen, Incorporated
for the
proposed indication of acute treatment of
migraine
headache with or without aura.
I would just also take the
opportunity to
refer people to the agenda. Incorporated in the
agenda are the questions which are posed
to this
committee which will be discussing and
voting on
today.
We won't be discussing or voting on prior
actions of the FDA including the
non-approvable
letter or any issues about a
approvability of the
product.
That is not our remit or discussion for
today.
So I would hope that the
presentations are
focused on what the committee will be
discussing
and deliberating about today.
When people speak, please
speak into the
6
microphone and turn the microphone
on. If you are
interested in speaking, raise your hand
or you can
turn the microphone on. Anuja, the Executive
Secretary, will keep track and will get
to people
who want to speak from the committee.
Just to the committee members,
the voting
committee members, please keep in mind
that, to
vote, you need to be here. So there is no leaving
of votes. Hopefully, there is no leaving until the
meeting is adjourned which is scheduled
to be at 5
o'clock.
Please plan your travels accordingly.
In a second, I am going to
introduce Mary
Ann Killian. There is a new procedure--I think we
are the inaugural run of it--for
disclosure of
conflicts of interest where Mary Ann
Killian reads
a statement and then each individual
member of the
committee reads their conflict
statement. When
that is concluded, Mary Ann has some
concluding
remarks and then we will move on with
the rest of
the agenda.
The only individual who does
report
conflicts of interest is Dr. Porter as
he is the
7
industry representative.
So Mary Ann Killian, the
Program Integrity
Advisor from the Ethics and Integrity
Staff.
Conflict of Interest Statement
MS. KILLIAN: Thank you very much. The
FDA is convening today's meeting of the
Peripheral
and Central Nervous System Drugs
Advisory Committee
under the authority of the Federal
Advisory
Committee Act of 1972. The advisory committee
meeting provides transparency into the
agency's
deliberative processes.
With the exception of the
industry
representative, all members of the committee
are
special government employees or regular
federal
employees from other agencies and are
subject to
federal conflict-of-interest laws and
regulations.
Consequently, in the interest
of
transparency and the spirit of
disclosure, the
following information on the status of
this
advisory committee's compliance with
federal ethics
and conflict-of-interest laws covered by
but not
limited to those found at 18 U.S.C. 208
and 21
8
U.S.C. 355(n)(4) is being provided to
the
participants in today's meeting and to
the public.
FDA has determined that
members of this
advisory committee are in compliance
with the
Federal ethics and conflict-of-interest
laws
including but not limited to 18 U.S.C.
208 and 21
U.S.C. 355 (n)(4). Under 18 U.S.C. Section 208,
applicable to all government agencies,
and 21
U.S.C. 355(n)(4), applicable to FDA,
Congress has
authorized FDA to grant waivers to
special
government employees who have limited
financial
conflicts when it is determined that the
agency's
need for a particular individual's
services
outweighs his or her potential financial
conflict
of interest.
Members who are special
government
employees at today's meeting, including
special
government employees appointed as temporary
voting
members, have been screened for
potential financial
conflicts of interest of their own as
well as those
imputed to them including those of their
employer,
spouse, minor child related to the
discussions of
9
today's meeting. These interested may include
investments, consulting, expert witness
testimony,
contracts/grants/CRADAs,
teaching/speaking/writing,
patents and royalties, and primary
employment.
Today's agenda involves a
review of New
Drug Application 21-645, proposed trade
MT100
Tablets, proposed for acute treatment of
migraine
headache with our without aura sponsored
by Pozen,
Inc.
MT100 is a combination of two approved drugs,
naproxen sodium, manufactured by
the Albemarle
Corporation, and metoclopramide
hydrochloride,
manufactured by Cosam S.p.A, a member of
the CFM
group.
This is a particular matters meeting during
which specific matters related to the
NDA will be
discussed
Copies of each acknowledgement
and
consent-to-disclosure statement signed
by each
participant at today's meeting who
received a
conflict-of-interest waiver along with
this
statement will be available for review
at the
registration table during this meeting
and will be
included as part of the official meeting
10
transcript.
A copy of the written
conflict-of-interest
waiver statements may be obtained by
submitting a
written request to the agency's Freedom
of
Information Office, Room 12A-30, of the
Parklawn
Building.
At this time, each member will
be asked to
state his or her name for the record and
announce
whether his or her participation in this
meeting is
based on a conflict-of-interest waiver.
Please state your name and
whether you
have received a waiver from the agency
to
participate in today's meeting. If you have
received a waiver, please describe the
details of
the interest or interests for which the
waiver has
been granted. If the agency has reviewed your
reported interest and determined that
you do not
require a waiver, please indicate that
for the
record.
I guess we will start with
you.
DR. KIEBURTZ: I will be the exemplar. I
am Dr. Karl Kieburtz. I am a neurologist and on
11
the faculty of the University of
Rochester in
Rochester, New York. Based on the agenda for
today's meeting and the information
regarding my
financial and other interests required
to be
reported to the agency prior to my
participation
today as a committee member, I have not
received a
conflict-of-interest waiver to
participate in
today's meeting. That means I don't need a waiver.
Next is Dr. Porter.
DR. PORTER: Pass.
DR. KIEBURTZ: If you would just introduce
yourself for the record.
DR. PORTER: Sure.
I am Roger Porter. I
am a neurologist twenty years at the
NIH, ten years
at Wyeth. I am now a consultant.
DR. HUGHES: I am Michael Hughes. I am
Professor of Biostatistics from Harvard
University.
Based on the agenda for today's meeting
and the
information regarding my financial and
other
interests required to be reported to the
agency
prior to my participation today as a
committee
member, I have not received a
conflict-of-interest
12
waiver to participate in today's
meeting.
DR. KOSKI: I am Dr. Carol L. Koski. I am
a Professor of Neurology at the
University of
Maryland School of Medicine. I have received a
waiver for ownership of stock in two
competing
firms.
The first is valued between $5,001 and
$25,000.
The second is valued between $25,001 and
$50,000.
DR. SACCO: Hi.
Ralph Sacco. I am a
Professor of Neurology and Epidemiology
and
Director of Stroke and Critical Care at
Columbia
University. I have received a waiver for my
service as a consultant for a competing
firm. I
also serve on the Data and Safety
Monitoring Board
for a competing firm and I receive less
than
$10,001 per year from each firm.
DR. GOLDSTEIN: I am Dr. Larry Goldstein.
I am a Professor of Medicine at Duke
University and
Director of the Duke Center for
Cerebrovascular
Disease.
I have received a waiver for consulting
for four competing firms and I receive
less than
$10,001 per firm per year from three of
the firms
13
and between $10,001 and $50,000 per year
from the
fourth firm. In addition, I serve as a member of
two advisory boards and two steering
committees for
competing firms and receive less than
$10,001 per
year from each firm.
DR. JUNG: Hi. My
name is Lily Jung. I
am a neurologist with the Seattle Neural
Science
Institute and Swedish Medical
Center. I am also a
Clinical Associate Professor at the
University of
Washington. I have received a waiver for ownership
of stock valued from $5,001 to $25,000
in a
competing firm.
DR. FAHN: Good morning.
I am Dr. Stanley
Fahn.
I am a Professor of Neurology at Columbia
University subspecializing in the field
of movement
disorders. I have received a waiver for serving on
steering committees for two competing
firms. In
addition, I also serve as a consultant
for two
competing firms. I receive less than $10,001 per
year from each firm.
DR. LENAERTS: Good morning.
Marc
Lenaerts, Assistant Professor,
University of
14
Oklahoma, Department of Neurology, a
headache
specialist. I have received a waiver for serving
on three speakers bureaus. One is between $10,001
and $50,000, and two are $10,000 or
less.
DR. WELCH: Good morning.
I am Dr.
Michael Welch. I am a Professor of Neurology at
Rosalind Franklin University of Medicine
and
Science.
I have received a waiver for serving as a
consultant for two competing firms and I
am also an
advisory board member for two competing
firms and
serve on the steering committee for a
competing
firm.
I receive less than $10,001 per year for
each firm.
DR. SMITH: Good morning.
I am Professor
Sheila Weiss Smith. I am an Associate Professor at
the University of Maryland Schools of
Pharmacy and
Medicine. I have not received a
conflict-of-interest waiver to
participate in
today's meeting.
DR. JESTE: Good morning.
I am Dr. Dilip
Jeste.
I am Professor of Psychiatry and
Neurosciences at the University of
California, San
15
Diego, and the San Diego V.A. Healthcare
System. I
have received a waiver for advisory
board
activities for a competing firm for
which I receive
less than $10,001 per year.
DR. GREEN: I am Dr. Mark Green. I am a
Clinical Professor of Neurology at
Columbia
University and Director of the Columbia
University
Headache Center. I have received a waiver from my
employer's contracts and grants with three
competing firms. My employer receives less than
$100,000 from one, between $100,001 and
$300,000
from a second and more than $300,000
from a third.
MS. KILLIAN: Thank you very much.
Lastly, Dr. Roger Porter is the Industry
Representative on the committee today
and he will
be acting on behalf of all related
industry.
In the event that the
discussions involve
any other products or firms not already
on the
agenda for which an FDA participant may
have a
financial interest, all meeting
participants are
reminded that they are required by 18
U.S.C. 208 to
exclude themselves from such deliberations
and
16
announce their exclusion for the record.
Finally, in the interest of
public
transparency, with respect to all other
participants, we ask that they publicly
disclose,
prior to making any remarks, any current
or
previous financial involvement with any
firm whose
products they may wish to comment upon.
Thank you very much. This concludes my
statement.
DR. KIEBURTZ: Thank you everyone for
doing that. For an inaugural run, I think that
went pretty well.
I would just like to point to
the agenda
before letting Dr. Katz begin which is,
some people
know, the sponsor will have
approximately an hour
and fifteen minutes, up until the 9:45
break, to
give their presentation. We will then break and
then there is a presentation from the
FDA.
There will then be the
opportunity for the
committee to ask questions about the
content of
those presentations to the
presenters. Then we
will break for lunch. There will be a public
17
hearing after that and then a discussion
amongst
the committee members after that.
During those discussions, the
committee
members may ask questions of the
presenters
regarding details of their presentation.
Presenters may not interject or
contribute to that
discussion voluntarily, just so people
know the
rules of the game here.
If you have questions that
arise during
presentations, the FDA's presentation
slides are
numbered. You may want to note them. You may want
to note the slides of a presenter so
that you can
refer back to them with reference when
you pose a
question.
On the FDA side of the table,
I would like
to introduce four people. It looks like it flows
from right to left from my sitting. Dr. Robert
Temple, Dr. Rusty Katz, Dr. Bastings and
Dr.
Southworth.
Dr. Katz?
Overview of Issues
DR. KATZ: Thanks, Dr. Kieburtz. I want
18
to be very, very brief. I just have a couple of
points I want to make but, first, I want
to add my
welcome to the committee. Thanks for coming.
Particularly we have several new
members. I would
like to thank them for agreeing to serve
on the
committee.
I would also like to thank Dr.
Kieburtz
for agreeing to chair the
committee. It can be a
tough job. I would also especially like to thank
our invited guests, of whom we have
quite a few,
who are experts to help us deal with
this
interesting issue. In particular, I would like to
thank Dr. Jinnah who has graciously
agreed to
actually be part of the presentations
this morning.
So thanks very much to everybody for
coming.
As you know, we are here to
discuss NDA
16-145 submitted by Pozen for the use of
MT100
which, as you have heard and which you
know, is a
combination of naproxen and
metoclopramide for the
treatment of acute migraine.
Actually, we are asking you
today to
address a type of question that is
actually fairly
19
unusual for the committee to deal with
and that is
because many of the questions that we
are going to
be asking you to consider are
hypothetical in
nature.
Those of you who have been on
the
committee or have seen previous
committee meetings
know that, in a typical case, when we
bring you a
new drug application, we would ask you
whether or
not the application contains sufficient
evidence of
safety or effectiveness in order to
support
marketing approval.
But, today, as Dr. Kieburtz
has already
stated, we are not primarily interested
in the
question of whether or not the sponsor
submitted
substantial evidence of effectiveness
for the
treatment of acute migraine. We have already
decided that they have not done so, in particular
because we are unsure that they have
presented
sufficient evidence of effectiveness for
the
combination, itself, as a treatment for
acute
migraine.
But, perhaps, more importantly
for today's
20
discussion, we have determined that they
have not
demonstrated a contribution of one of
the
components to the overall effect of the
drug and
that component is metoclopramide. I think we will
have a lot of discussion about that
particular
question today.
You will, though, of course,
hear some
more or less detailed presentations of
that
effectiveness data that we have already
ruled on in
a sense.
You will hear from the company and you
will hear, to some extent, from us as
well, from
Dr. Bastings. We would hope that you would
primarily consider those data in the
context of
helping to inform your answers to the
series of
hypothetical questions that we are going
to ask
you.
In particular, we would like
you to think
about the previous effectiveness data in
the
context of giving us your advice as to
whether or
not, if the sponsor does perform an
additional
study or additional studies in a
particular
population which you will hear about,
whether or
21
not the results--if the results of these
new
studies or new study are more or less of
the same
magnitude as what has been seen already,
whether or
not you would think that would justify
approval of
the combination given the potential
risks of the
treatment.
Of course, the potential risks
of the
treatment are the underpinnings for the
second
serious of hypothetical questions we
want to ask
you.
Specifically, we are interested to know your
views about the likelihood of occurrence
and,
perhaps, even estimates of the frequency
of
particular adverse events that we are
concerned
about which, as you know, are tardive
dyskinesia,
primarily, but, in additional, other tardive
movement disorders and possibly
neuroleptic
malignant syndrome associated with the
chronic
intermittent use of metoclopramide as it
would be
presumably used in the treatment of acute
migraine.
This series of questions is
hypothetical
because the current data on the risks
for these
adverse events associated with
metoclopramide, such
22
as they are, don't speak directly to the
question
of what the frequency of--what they
might be when
the drug is given in the regimen that
the sponsor
proposes; namely, chronic intermittent
use, as is
typical for an acute-migraine treatment.
As difficult as those
questions might be
to answer, we would like you to go even
further and
venture an opinion about what sort of
possible
dosing recommendations, if any, actually
could be
adopted that might reduce the risks to
an
acceptable level and then ask you to
discuss what
you think that possible result and level
of risk
might be. So these are all, obviously, questions
for which we do not have adequate data.
That is what makes it
difficult. We know
these are difficult questions, but
partly because
they are so difficult, and partly
because we think
these questions are very important to
try to answer
from the perspective of public health,
given the
large prevalence of acute migraine in
the
population, that is why we have come to
you today.
So, again, thank you for
coming. I want
23
to thank you in advance for all the hard
work that
you have done already in reading the
documents and
in today's discussion. So thanks again and I look
forward to an interesting and productive
meeting.
Thanks.
DR. KIEBURTZ: Thank you, Dr. Katz.
Actually, I realize I was a
little remiss
in introducing all of you. Maybe, as we have all
had the chance to introduce ourselves
around the
table, Dr. Temple, maybe you could start
so that
everyone knows who you all are.
Also, to follow up on Dr.
Katz' comments,
just before you do that, Dr. Temple,
these are
difficult questions and they are unusual
questions.
I hope the committee members feel
comfortable
voicing if they are uncertain about that
and I will
be happy, as chair, to direct back to
the FDA
questions about clarifying as to whether
we are
answering the questions they had in mind
and
getting clarity that we are providing
them the
advice that they are seeking from us
because it is
a little bit unusual.
24
So, if people are a little
uncomfortable
about that, that is how we can do
that. We can ask
questions of them to be certain we are
addressing
the issues at hand.
So, Dr. Temple, please.
DR. TEMPLE: Good morning.
I am Bob
Temple.
I am the Director of ODE I. That
is
office in which the Division of
Neurology Products
lives.
I have not received a waiver.
DR. KATZ: I am Russ Katz. I am the
Director of the Division of Neurology
Products. I,
too, am not allowed to have a conflict
of interest.
DR. BASTINGS: I am Eric Bastings. I am a
clinical team leader in the Division of
Neurology.
DR. SOUTHWORTH: I am Mary Ross
Southworth, a safety evaluator in the
Office of
Drug Safety.
DR. KIEBURTZ: Next on the agenda is
presentations from the sponsor.
Sponsor Presentation, Pozen,
Incorporated
Introduction and
Summary
DR. REESE: Good morning and thank you.
25
(Slide CC-1-2)
Pozen wants to thank the FDA for
assembling the Peripheral and Central
Nervous
System Drugs Advisory Committee today to
review our
naproxen-metoclopramide combination
product called
MT100 for the acute treatment of
migraine with and
without aura.
(Slide CC-3)
Let me briefly review an
outline of
Pozen's presentation for this
morning. Following
my introductory comments, Dr. Schapira,
Professor
and Chair of Neurology at the Royal Free
and
University College Medical School in
London and
Professor of Neurology at Queens Square,
will
present an overview of tardive
dyskinesia with
metoclopramide use.
Dr. Alexander, Senior Vice
President and
Chief Medical Officer at Pozen, will
briefly review
the efficacy data for MT100 as contained
in our
NDA.
Dr. Matchar, Professor of Medicine and
Director of the Center for Clinical
Health Policy
Research at Duke University, will discuss
the
26
potential role of MT100 in migraine
therapy and the
benefit-to-risk ratio of MT100.
Dr. Silberstein, Director of
Jefferson
Headache Center in Philadelphia and the
current
President of the American Headache
Society, will
review clinical considerations in
migraine
treatments. Then I will close our presentation of
this morning.
(Slide CC-4)
A bit of history. Pozen filed the IND for
MT100 in 1997 and undertook a
preclinical, clinical
and pharmaceutical development
program. There were
several discussions in meetings with the
FDA over
the next six years which culminated in
the
submission of the NDA in July,
2003. Pozen
believed that the totality of the data
in the NDA
supported approval of the
fixed-combination
product.
However, the FDA did not agree with Pozen
and issued a not-approvable letter in
May, 2004.
A critical-path meeting was
held in late
October, 2004 with the Division
Director, Dr. Katz,
and the Office Director, Dr. Temple. As a result
27
of that meeting, the FDA suggested an
advisory-committee meeting be convened
to address
the potential risk of tardive dyskinesia
with MT100
before we undertook any additional work.
(Slide CC-5)
That brings us to today's
meeting which
really revolves around one central
question; does
the potential risk of tardive dyskinesia
preclude
the ultimate approval of MT100, whether for
all
patients or for a readily identifiable
group of
patients who receive the maximum
benefit.
(Slide CC-6)
MT100 is a patented
pharmaceutical tablet
formulation which is basically a pill inside a
pill.
The core consists of the 500 milligrams of
naproxen sodium that is sprayed with an
insulating
coat followed by a spray coating of 16
milligrams
of metoclopramide hydrochloride, which is
equivalent to 13-and-a-half milligrams
of
metoclopramide base, then followed by a
color coat.
The tablet is designed to
release
metoclopramide immediately into the
stomach to
28
alleviate the gastroparesis often
associated with
migraine following the release of the
long-acting
drug, naproxen, after it leaves the
stomach.
Please note that the doses of both
components are
well below the maximum daily doses
approved for
these two products for other
indications.
(Slide CC-7)
In May, 2004, the FDA issued a
not-approvable letter for MT100 citing
both
efficacy and safety concerns. The FDA concluded
that the efficacy data for MT100
provided only
modest benefit over naproxen at 24 hours
and that
this benefit, coupled with the possible
risk of
metoclopramide-induced tardive
dyskinesia, did not
warrant approval of MT100.
The not-approvable letter also
stated that
the data submitted in the NDA did not
provide a
significant benefit for all of the
migraine-associated symptoms at two hours versus
placebo in two well-controlled
studies. The FDA
did agree that one study was considered
to have met
all the endpoints necessary for
approval.
29
Therefore, the FDA felt that
the potential
risk of developing tardive dyskinesia
was not
outweighed by the 4 to 6 percent benefit
of the
MT100 over the active control, naproxen,
at 24
hours.
(Slide CC-8)
Now, regarding tardive
dyskinesia, the
not-approvable letter states, "The
absence of any
detected cases among 300 patients is
consistent
with the true rate of TD of about 1
percent, an
unacceptably high risk in the absence of
any
advantage of the product."
The FDA's mathematical
calculation of 1
percent is derived from the upper limit
of the 95
percent confidence interval around zero
which we
believe is based on the 300 subjects in
the
long-term safety study. Any implication that the
true rate approaches 1 percent is
unfounded based
on the available scientific data in the
literature,
the spontaneous case reports from the
U.S. and the
U.K., national safety databases and our
own
clinical-trial experience in treating
over 3700
30
patients with MT100.
We feel that the risk of tardive
dyskinesia is very low and, certainly,
much less
than 1 percent. While approximately 2700 of these
patients treated only single attacks,
our 12-month
safety data that we conducted was actually
three
times larger than the FDA had requested.
This study exposed over 1000
subjects to
MT100 for three months, over 600
subjects for 6
months and over 300 subjects for 12
months treating
over 23,000 individual migraine attacks
and there
were no reports of tardive dyskinesia in
these
studies.
(Slide CC-9)
Now, metoclopramide had been
on the market
for over 20 years when Pozen submitted
the NDA and
there were never any concerns raised by
the FDA as
far as I am aware regarding tardive
dyskinesia
during the development of MT100. Even though we
saw no cases of tardive dyskinesia
during the
development program, to be conservative,
Pozen
mimicked the current metoclopramide
labeling found
31
in Reglan, from the Warnings Section of
the
approved label, regarding any possible risk
of
tardive dyskinesia.
The Reglan label states,
regarding tardive
dyskinesia, that both the risk of
developing the
syndrome and the likelihood that it will
become
irreversible are believed to increase with
the
duration of treatment and the total
cumulative
dose.
Less commonly, the syndrome can develop
after a brief treatment period at low
doses. In
these cases, the symptoms appear more
likely to be
reversible.
I would like to stress, again, that the
use of MT100 in the migraine population
exposes
patients to both a low dose, 16
milligrams, of
metoclopramide hydrochloride and to an
episodic use
of about three to six times per month.
(Slide CC-10)
Based on the available
scientific
evidence, Pozen submits that the risk of
tardive
dyskinesia associated with
metoclopramide use is
very low and should be even lower with
the episodic
32
use of MT100. The therapeutic dose of
metoclopramide hydrochloride, as I said,
in MT100
is only 16 milligrams. The data from the long-term
safety study indicates that the expected
use of
MT100 is only about four doses per
month.
Dr. Schapira will review the
spontaneous
national safety databases from both the
U.S. and
U.K. and the scientific literature. There have
been very few cases of tardive
dyskinesia reported
from the chronic use of metoclopramide
as a single
ingredient over the past 40 years and,
to our
knowledge, no cases of tardive
dyskinesia have been
reported with the episodic use of
metoclopramide.
As I said, there were no cases
of tardive
dyskinesia seen in our clinical-trial
program
either.
Therefore, to the best of our knowledge
from the literature, the national safety
databases
and experts in the field, the risk of
developing
tardive dyskinesia from the episodic use
of MT100
should be lower than currently approved
metoclopramide-containing products. Therefore,
Pozen feels its potential risk of
tardive
33
dyskinesia should not preclude the
ultimate
approval of MT100.
(Slide CC-11)
Since MT100 is a
fixed-combination
product, it must also satisfy the FDA
combination
policy as shown on this slide which
simply states
that, "Two or more drugs may be
combined in a
single form when each component makes a
contribution to the claimed effects and
the dosage
of each component is such that the
combination is
safe and effective for a significant
patient
population requiring such concurrent
therapy as
defined in the labeling."
We believe MT100 satisfies this policy.
(Slide CC-12)
Dr. Alexander will review the
efficacy
data for MT100 in a few moments, but I
would like
to share a few highlights of what he
will show you.
There was a significant
improvement in the
primary endpoint of sustained pain
response over 24
hours in five of six studies versus
placebo or the
pseudoplacebo metoclopramide. One study did not
34
achieve significance and the p-value was
0.054.
The data from the two
component studies
both demonstrate that each component of
metoclopramide makes a significant contribution
to
the claimed effects for all patients but
an even
greater effect in a significant patient
population
experiencing migraine attacks without
nausea.
In addition to the primary
24-hour
sustained pain endpoint, the FDA
requested that we
evaluate migraine efficacy endpoints at
two hours
versus placebo. In all six efficacy studies, MT100
was always significantly better than
placebo for
pain at two hours. We also showed improvement over
the associated symptoms of nausea,
photophobia and
phonophobia at two hours.
Although these studies were
not powered to
show a difference in these secondary
symptoms, in
most cases, MT100 was numerically, if
not
statistically, superior to placebo.
(Slide CC-13)
In conclusion, I believe that
the
potential risk of tardive dyskinesia
should not
35
preclude the ultimate approval of MT100.
(Slide CC-14)
Next I would like to introduce
Dr.
Schapira, Professor and Chair of
Neurology at the
Royal Free and University College Medical
School in
London and Professor of Neurology at
Queens Square,
who will summarize the available
information on
tardive dyskinesia associated with
metoclopramide
use.
Thank you.
DR. KIEBURTZ: Dr. Reese, before you--does
anybody have just a quick clarification
or--okay.
Thank you.
Overview of Tardive
Dyskinesia
DR. SCHAPIRA: Thank you, Dr. Reese, and
thank you, Dr. Kieburtz, and thank you
to the
committee for the opportunity to come
and speak to
you this morning.
I guess I am coming here
wearing two hats.
The first is of a neurologist, a general
neurologist, in the U.K. who, in
outpatient clinic,
sees a spectrum of neurological
disorders, a
36
significant proportion of which, of
course,
includes headache and a significant
proportion of
that, in turn, includes migraine.
The second hat is that of a
neurologist
with a specific interest in movement
disorders. So
it is with those two hats, if you wish,
that I am
going to cover some specific areas this
morning.
(Slide CC-15)
The first is to address the
issue of why
use metoclopramide in migraine and the
second is
specifically to address the risk of
tardive
dyskinesias, or TD, with metoclopramide
use. I
would like to divide my comments on this
into three
areas; the chronic, intermittent and
episodic use.
I will come back each of those in turn.
(Slide CC-16)
Just to begin with why use
metoclopramide
in migraine.
(Slide CC-17)
I will cover this only briefly
because
others will also comment on this, but we
know that
it enhances absorption of orally
administered
37
analgesics. It is an anti-nauseant and
anti-emetic. A meta-analysis indicates that
parenteral metoclopramide seems to have
a specific
anti-migraine activity on its own.
(Slide CC-18)
The advantages, if you wish,
of
metoclopramide in migraine have actually
been used
in the U.K. because we have, for 25
years, actually
had access to three drugs, all of which are
metoclopramide analgesic
combinations. The first
is MigraVess. The second is Paramax, and MigraMax.
MigraVess was available between 1980 and
1999 and
was then withdrawn in favor of Migramax
because of
the higher dose of aspirin compound in
the latter.
All of these three compounds,
as I say,
contain 10 milligrams of metoclopramide
per dose
and the maximum recommended dose in the
U.K. is
three dose per 24 hours, so a 30-milligram-per-day
dose of metoclopramide.
There is no restriction in the
U.K. on the
number of times a patient may take this
compound
per week, per month, et cetera, so long
as they do
38
not exceed the three-times-per-day,
24-hour, dose.
I should also point out that, for
general use,
metoclopramide has been available in the
U.K. since
1964.
(Slide CC-19)
The use of these
metoclopramide-analgesic
combinations in the U.K. have been found
useful.
In fact, they have now been incorporated
into the
U.K. Guidelines for the management of
acute
migraine. The first step is a simple analgesic.
The second step is, then, the
metoclopramide-analgesic combinations
given orally
or, if necessary, given by
suppository. The third
step is the use of a triptan.
We have found, in clinical
practice in the
U.K., that that middle step, that Step
2, is a very
useful practical intermediate step
between the use
of simple analgesics and the use of a
triptan.
(Slide CC-20)
Now, I would like to come on
specifically
to address the issues of tardive
dyskinesia. In
terms of the use, I will focus first on
chronic
39
use.
This I am going to define, really, as the
most frequent, most common, use in the
U.S.,
particularly, of Reglan, or
metoclopramide, for its
gastrointestinal uses, and also in the
U.K. we have
an equivalent drug which we call
Maxolon, again
with the same range of uses for
gastrointestinal
disturbances.
(Slide CC-21)
Let me, first of all, though,
before
moving on to the surveillance data,
begin with a
view of tardive dyskinesia. There are several
different definitions of tardive
dyskinesia, so
what I have tried to draw out is some of
the
commonalities between them.
I think we could say that it
is a syndrome
consisting of potentially irreversible
involuntary
dyskinetic movements which can affect
any part of
the body but which predominantly affect
the
orolingual-buccal region. It has traditionally
been associated with chronic, and that
is 30 days
or
more, use of a dopamine antagonist, generally
speaking, at the higher dose ranges of
the those
40
antagonists.
But some definitions of TD
also include
daily use for three months, or daily use
for one
month if the patient is 60 years or
more, onset
during use or, alternatively, onset with
four to
eight weeks of cessation.
The pathogenesis of tardive
dyskinesia is
not fully understood but it is thought
to include
the development of supersensitivity of
the
dopaminergic system. The prognosis of TD, once it
develops, is variable and, again, the
precise
handles on this can vary. Two studies, for
instance, quoted in the helpful FDA
submission,
suggest that 33 percent of patients may
resolve
spontaneously in two years and another
29 percent
over six months.
But, certainly, TD can be
irreversible and
can be extremely distressing.
(Slide CC-22)
I would like to just now move
quickly to
some of the surveillance data that is
available on
TD, the first of which, looking at the
association
41
between TD and metoclopramide came from
Scandinavia. Between 1977 and 1981, there were
established 11 million doses and they
identified 11
cases of TD.
Then the first of two U.K.
studies. The
first was a retrospective analysis of
the Committee
of Safety of Medicines. This is a yellow-card
system whereby medical practitioners
will send in a
yellow card to the CSM when they identify
an
adverse drug reaction.
Looking at the years between
1967 and
1982, so about 15 years, of Maxolon
only--so this
is looking at the use of, if you will,
the Reglan
equivalent in the U.K.--it established 15.9
million
prescriptions over this 15-year period,
so just
over 1 million per year. They identified four
cases of TD.
Then there was a prospective
study by the
same author looking at a time point in
1986 over a
six-month period where they
prospectively looked at
prescriptions, again for Maxolon, the
Reglan
equivalent, not for the
metoclopramide-analgesic
42
combination. So, for this Reglan equivalent, they
identified just over 2-and-a-half
thousand
prescriptions or patients who were given
prescriptions and found 25
extrapyramidal events
with 12 dystonias, eight akathisias, five
drug-induced Parkinsonism but no case of
tardive
dyskinesia.
It might be helpful just for
me to set in
context the dosage issues of
metoclopramide in the
form of Reglan or Maxolon and that
suggested for
MT100.
(Slide CC-23)
Reglan, here, I understand, is
used at a
recommended dose of 10 to 15 milligrams
per day, in
some cases up to 20 milligrams, but the general
recommendation is for 10 to 15, up to
four times a
day.
So the maximum dose would be 60 milligrams a
day.
Then the course of the medication varies
according to the indication it is used
for, up to
eight weeks or up to 12 weeks.
If you look at the maximum
calculated
recommended exposure for one course, you
come to
43
just over 5 grams of
metoclopramide. But, if you
take a conservative estimate of
usage--let's say if
you half that recommended maximum--you
would come
out with, let's say, 10 milligrams four
times a day
and for eight weeks rather than 12
weeks.
You come out to about 2.24 grams, so
that is 45
percent of the maximum recommended dose
on that
schedule.
Just to put this in context,
that
half-exposure, if you wish, half of the
maximum
recommended exposure, is the equivalent
to treat
166 doses of MT100, 166 migraine
attacks, or, if a
patient were to take MT100 at its
maximum
recommended dose of 6 tablets per month
every
month, they could take 2.3 years of
MT100.
In fact, the median number of
doses per
year of MT100 in the 302 study was 22,
so if you
translated this into practical MT100
usage, this
would be the equivalent to
seven-and-a-half years
of Reglan at half its maximum
recommended dose or
15 years of practical use of MT100 at
the maximum
exposure of Reglan in one specific
course.
44
So that just sets the sort of
dosage
issues in context.
(Slide CC-24)
I would like to now come to
this very
helpful review by Shaffer, Dr. Shaffer,
who was--he
and two other colleagues from the FDA
and another
from Duke published a paper looking at
the U.S.
reporting system for the period 1968 to
2003, so
over 35 years.
Now, just for the 10-year
period between
1994 and 2003, they estimated that there
were about
42 million scripts for metoclopramide. They
identified in their database 87 cases,
40 of which
made that predetermined definition of
TD. But I
will talk about this in a little bit
more detail.
(Slide CC-25)
This is a 35-year review. Interestingly,
just when they looked at all the scripts
for
patients who were given metoclopramide,
62 percent
of those were intended for women and 24
percent,
almost a quarter, were intended for
patients who
were age 70 or over. The authors actually didn't
45
include the use of migraine in their
estimations
but I understand from the FDA submission
that they
have now calculated that 2 percent of
this use was
for migraine and, no doubt, they will
address that
issue specifically themselves.
Now, the predetermined
definition of TD
that these authors used to identify
their cases was
metoclopramide exposure for 30 days or
more and
documented involuntary movements or
symptoms. As I
say, they identified 87 separate reports
but 60 of
these had involuntary movements and 53
had duration
of use of 30 days or more.
In practice, 40 of the 87 met
the
predetermined criteria of TD. I note that, in the
FDA submission, their number is 68 and,
again, no
doubt, they will address that
separately.
Of those that did develop TD,
the mean age
was 60 with a range of 11 weeks to 95
years, and 65
percent of the TD patients were women
which
corresponds, actually, quite well with
the 62
percent women that were given the
scripts in the
first place.
46
The mean dose was 33
milligrams per day,
the duration 753 days although, again,
the FDA
submission, I note, identifies the median
as 180
days.
Six of the patients were on anti-psychotics
as well as metoclopramide and 22 of them
were
considered to have permanent disability,
eight of
whom needed a visit to the emergency
department or
hospitalization because of their TD.
(Slide CC-26)
I would like to now move from
what I have
considered in terms of the Reglan or
Maxolon type
usage in the U.K. and the U.S. to the
intermittent
or episodic. Here I would like to draw my own
distinction between these.
In my understanding,
intermittent
pharmacotherapy is a course of treatment
separated
by a period of treatment followed by
another course
of that same treatment so, over a
prolonged period,
intermittent doses with periods in
between without
the medication. I contrast that with episodic PRN
or as in "when required" use
such as, for instance,
as used in acute migraine attacks. That is what I
47
am going to refer to as episodic use.
(Slide CC-27)
Let me just remind you that,
in the U.K.,
we have, for the last 25 years, had
access to these
metoclopramide-analgesic combinations
for the
treatment, the episodic treatment, of
acute
migraine the dosage of which, in any 24
hours, is
30 milligrams. Looking at the equivalent,
incidently, in MT100, the maximum daily
dose is
13.5 milligrams in terms of the base of
metoclopramide which is the equivalent
in these
combinations.
In the U.K., it is estimated
almost
100,000 patients receive a total of
about 8 million
doses of these combinations per
year. In the
five-year period 1999 to 2003, there
were estimated
to be a total of 40 million doses. So these are
drugs which are used relatively commonly
for the
treatment of acute migraine in the U.K.
(Slide CC-28)
Now, the ADROIT database is a
physician
database. It records physician-identified and
48
reported adverse events to a central,
now
computerized, database and it records
prescriptions
as well as adverse events, so it is
particularly
helpful.
In the period 1964, when
metoclopramide
first became available, to 2005, so
about a 40-year
period, they were able to collect data
on
metoclopramide. But what is, I think, of
particular interest this morning is that
this
database is able to discriminate between
the
Maxolon-Reglan type use in the U.K. and
the use of
metoclopramide-analgesic combinations
for acute
migraine. So the database discriminates between
those two uses.
They found almost 3000 adverse-event
reports by any route of which 156 were
related to
the acute-migraine
metoclopramide-analgesic
combinations of which 69 were
neurological over a
period from 1980 to 2005 which is when
these
combinations have been available to us.
(Slide CC-29)
Just to look at little bit
more closely at
49
these 69 neurological events over that
25-year
period reported to this database, there
were 26
dystonias or oculogyric crises, eight
extrapyramidal disorders not specified,
three
dyskinesias which were not classified as
TD--they
were reversible after the patient
stopped their
medication--one of Parkinsonism, one of
akathisia
but no reports of choreiform movements
and no
reports over this 25-year period of
tardive
dyskinesias.
(Slide CC-30)
There were a collection of
other
neurological events; acute
extrapyramidal disorders
were numbered 14 and this may well
include things
like oculogyric crises, and then a
variety of other
neurological features. So that totals a number of
69
none of which were TD.
(Slide CC-31)
Just to make a comparison
between acute
episodic use of metoclopramide-analgesic
combinations for acute migraine and the
other
general use of metoclopramide, I have
listed there
50
the adverse events. You will see that there have
been reports, of course, of a variety of
neurological events including the
dystonia/oculogyric crises with the more
chronic
type of metoclopramide use, the sort of
Maxolon-Reglan type use, and 24 cases of
tardive
dyskinesia with the non-migraine use of
metoclopramide compared to the zero for
the
migraine use.
(Slide CC-32)
I would just like to very
briefly cover
the MT100 experience; nine phase 3
studies, 3,700
subjects, over 25,000 doses and a study
which took
just over a 1,000 patients to follow
them up over a
period of up to 12 months.
In the MT100 studies, there
were two
patients that experienced acute dystonic
reactions
but no patients that experienced tardive
dyskinesia.
(Slide CC-33)
Just looking at the
longer-term study,
1,000 patients recruited, 621 were
followed over
51
six months, 329 over 12 months, treating
23,000
migraine attacks. As I mentioned before, the
median number of doses per patient over
the 12
months was 22 and the mean number of
days between
each dose was almost 10.
(Slide CC-34)
So just looking at the--one
has to accept
somewhat limited MT100 data. We haven't seen any
cases of TD. But just looking at the U.K. data
where we have got data now for over 25
years, and
there is that period 1999 to 2003 where
specifically, just for that period, they
have
estimated 40 million doses, we haven't
had any
reports to the ADROIT database of any
cases of
tardive dyskinesia over that period.
(Slide CC-35)
I would like to summarize. I think we
have to accept that the MT100 experience
is
insufficient to exclude a small risk of
TD with its
usage.
But, moving to the larger U.K. experience,
I think we have had no reports of
analgesic-metoclopramide combinations
causing TD
52
and that is use for migraine over 25
years and at a
very conservative estimate, over 100,000
million
doses.
This, remember, is using a
dosage and a
frequency for these
analgesic-metoclopramide
combinations in the U.K. which is
greater than that
which is proposed for MT100.
(Slide CC-36)
The FDA briefing documents raised some
important topics and I would just like
to address
three of those specifically. The first is the
question that they asked, is there
sufficient
evidence that the chronic intermittent
administration of metoclopramide does
not carry the
same risk of TD as the chronic
administration.
I can say that the experience
from the
U.K. over the 25 years that we have had
them of
these metoclopramide-analgesic
preparations, the
answer is yes. Yes; we do have sufficient evidence
that the chronic intermittent
administration of
metoclopramide does not carry the same
risk of TD
as the chronic administration.
53
(Slide CC-37)
So, if the answer is yes, what
is the
maximum number of recommended monthly
doses to
avoid the risk of TD? Well, the answer to that is
not known. But I have to come back to the U.K.
experience just to mention that, over
the 25 years,
there have been no cases of TD using the
metoclopramide-analgesic combinations at
their
recommended dose and schedule which
exceeds that
for MT100.
(Slide CC-38)
Finally, this is an issue
which will be
addressed by other experts specifically
and that is
on medication-overuse headache, but the
question is
posed, do you believe that, based on the
existing
data on medication-overuse headache,
there is
evidence that the proportion of patients
prescribed
MT100 will likely take a number of
monthly doses
higher than that recommended.
Well, I can't answer this
question
specifically, of course, but I can only
say that if
this does happen, even if it does happen
with this
54
type of combination, the U.K. data don't
indicate
that it should lead to TD.
Thank you very much.
(Slide CC-39)
I would like now to pass to
Dr. Jim
Alexander who is Pozen's Chief Medical
Officer. He
will review the data on the efficacy of
MT100 in
migraine.
DR. KIEBURTZ: Same thing.
Anyone have a
point of clarification?
DR. SMITH: Could you go over with me, on
Slide CC-21, the definition of tardive
dyskinesia,
please--the definition. My question is, you say
some definitions include the duration of
exposure.
When do the definitions include
that? In other
words, is that a common use definition?
DR. SCHAPIRA: The definitions vary. As I
say, some definitions, looking at the
case studies
that have been published on TD and
metoclopramide
have required that the patient has been
taking
metoclopramide continuously for two
months, others
for three months. Some of the other studies like
55
the Shaffer review have said that the
patient
should be taking it for 30 days or more.
So there is some variation in
how people
define the requirement of metoclopramide
exposure
before they will associate it with TD.
DR. SMITH: I see.
So, if it doesn't meet
the duration of use, it would be dyskinesia,
not
TD?
Is that correct?
DR. SCHAPIRA: I think that would depend
on the individual study and the
interpretation of
the authors. For instance, in the Shaffer paper,
they identified that they would use the
definition
of 30 days or more. But they also recognized--for
instance, I think they reported on three
juvenile
cases, two infantile and one adolescent
case, that
developed tardive dyskinesia, I think
the two
infants following an overdose of
metoclopramide and
the adolescent also had some other
features.
So I think it depends clearly
how strictly
you want to define and whether you will comment
on
other cases that fall outside your
definition.
DR. SMITH: Okay.
Thank you.
56
DR. KIEBURTZ: Let's hold on that because
we will hear more about
definitions. If the
question is about TD
definitions--no? Go ahead.
DR. LENAERTS: Dr. Schapira, in sharing
your U.K. experience, what is your
estimate of the
prevalence of specifically migrainers
either
overusing metoclopramide-analgesic
combinations or
staying frequently or constantly at the
maximum
recommended dose, because you mention--
DR. KIEBURTZ: Excuse me.
I am just going
to stop.
If you have a clarification on what he
presented, that is one thing. Additional questions
about something he didn't talk about,
not yet.
DR. LENAERTS: Thank you.
I will hold.
DR. KIEBURTZ: Just clarifications of the
presented material. Dr. Katz?
DR. KATZ: A couple of questions. On
Slide 22, the second Bateman study, just
for
clarification, what the design was. That was a
prospective study?
DR. SCHAPIRA: No; that is a retrospective
study.
The CSM, yellow-card system.
57
DR. KATZ: The second one is the
yellow-card system. I thought you said it was a
prospective study.
DR. SCHAPIRA: No.
I'm sorry. The second
Bateman study that you see on the slide
there, the
one published in 1989, that was a
prospective
study.
DR. KATZ: Right; I am talking about the
second study.
DR. SCHAPIRA: I'm sorry.
I thought you
said second on the list.
DR. KATZ: Oh; I'm sorry. The second
Bateman study, the 1989. So that is prospective,
so those patients were followed and
their adverse
events were recorded contemporaneous
with their
occurrence.
DR. SCHAPIRA: Yes.
DR. KATZ: It was a true prospective--
DR. SCHAPIRA: Yes.
DR. KATZ: Okay.
Thanks. One other
question. Slide 28, which looks at the reports of
these events over a 40-year period, do
you know
58
anything about the temporal pattern of
those
reports?
In other words, were there more reports
earlier on and then reports started to
wane over
time which sort of happens all the time,
we think,
with spontaneous reports? Do you know anything
about that?
DR. SCHAPIRA: No; I can't comment on
those.
I can only say that the system has been in
place, of course, for all of that
time. More
recently, over the past years, it has
been
computerized. So the ADROIT system is a fairly
responsive system which is linked to
primary-care
computers throughout the U.K. But I can't tell you
about the pattern of those over the
years.
DR. KATZ:
Just one other, if I can,
question. The previous slide, 27, which looks at
the combination, the actual
acute-migraine
treatments, do we know the actual doses
that people
took?
As you say, the maximum dose, I guess, is 30
a day.
Do we know? I don't know. Maybe we figure
it out from the numbers, but do we know
what people
actually took?
59
DR. SCHAPIRA: No; we don't know precisely
how many they took, only how many were
prescribed.
As I say, it is estimated as an average
of 85 per
person, but that doesn't tell you how
many they
took in an individual dose. So I don't have the
data on that.
DR. KATZ: Dr. Fahn?
DR. FAHN: If we can go back to slide 22,
again, for a clarification, the second
Bateman
study, the 1989 study, zero cases of TD,
do you
know what definition of TD they used to
come to
that number?
DR. SCHAPIRA: No.
They did not specify
their definition of TD.
DR. KIEBURTZ: Dr. Goldstein?
DR. GOLDSTEIN: I am not all that familiar
with your drug-reporting system. Two questions
about it. One is how compulsive is the use of
this?
In other words, how often do you think you
are actually getting reports about
things that are
actually happening.
The second question related to
it is does
60
the system allow for validation somehow
of these
reports because, especially with
primary-care
physicians, it is not clear to me how
accurate
these reports may be about particular
types of
problems.
DR. KIEBURTZ: It is a little evaluative.
It is a good question. Can we hold on it because I
am conscious that the sponsor only has a
certain
amount of time to present. I don't want to
infringe on that.
One last question about the
second Bateman
study that you have already had
questions about.
Was that only new prescriptions?
DR. SCHAPIRA: Yes.
DR. KIEBURTZ: Thank you.
DR. SCHAPIRA: I'm sorry; can I just
clarify.
That was the number of prescriptions that
were given during that six-month period. So it
didn't specify whether that was a
renewed
prescription for that individual or not.
DR. KIEBURTZ: Oh; I see.
Okay. Thank
you.
61
DR. SCHAPIRA: Thank you.
I will now hand
over to Dr. Alexander.
Review of MT100
Efficacy
DR. ALEXANDER: Thank you, Dr. Schapira.
Although the potential risk of
tardive
dyskinesia is the primary focus of this
meeting,
when Pozen and the FDA discussed the
meeting, we
agreed that the committee should have
the
opportunity to review data described in
the
efficacy of MT100.
(Slide CC-40)
My presentation will,
therefore, summarize
the results of studies designed to
evaluate the
efficacy of MT100 using two different
trial designs
which evaluated the acute treatment of
single
migraine attacks.
First, I will show the results
from the
phase 3
studies which evaluated MT100 versus
placebo or metoclopramide as a
pseudoplacebo.
These studies examined the efficacy of
MT100 as a
migraine drug using those endpoints that
are
usually required for the approval of new
migraine
62
therapies.
Secondly, I will review the
data from the
two component controlled trials which I
will call
the factorial studies. These are the trials that
compared MT100 to its two individual
components.
Now, as you have heard, the efficacy of
naproxen
sodium as a component of MT100 is really
not in
question. So my focus in discussing these data
will be on comparisons between MT100 and
naproxen
sodium which directly address the
contribution of
metoclopramide as a component of MT100.
(Slide CC-41)
The MT100 phase 3 program was
quite
extensive and almost 6,000 subjects were
enrolled
in six controlled trials treating single
migraine
attacks.
Four studies directly compared MT100 with
placebo while, in the two factorial
studies shown
below, 301 and 304, metoclopramide was
considered a
pseudoplacebo.
2,355 subjects received single
doses of
MT100.
Did these studies provide evidence that
MT100 was an effective migraine
drug? Well, Pozen
63
believes that the data clearly showed
this.
(Slide CC-42)
This table lists the six
studies in the
left-hand column. It is arranged to show the 30
individual different primary and
secondary
endpoints in the five columns to the
right. Study
306, which is at the top, is the study
that was
accepted by the FDA as demonstrating the
efficacy
of MT100. The two columns on the far left show the
key pain endpoints--that is, sustained
pain
response at 24 hours, which was the
primary
endpoint in four studies, and the
two-hour pain
response in the second column was a key
secondary
endpoint in five studies.
As shown now on the slide, in
11 of 12
comparisons, MT100 was significantly
superior to
the comparator for each of these pain
endpoints.
In Study 303, which had an unbalanced
randomization
with a smaller number of placebo
recipients, the
p-value for sustained pain response was
0.054.
But in all six studies, the
efficacy of
MT100 over the comparator for the
two-hour pain
64
response, shown in the second column,
was
significantly superior. These results provide
clear and compelling evidence that MT100
provides
effective two-hour pain relief, the
usual
regulatory endpoint in migraine trials,
as well as
providing sustaining pain responses at
24 hours.
I will provide a better
definition of
sustained response in a few
minutes. I want to
mention the efficacy on the associated
symptoms.
Efficacy for the associated symptoms of
nausea,
photophobia and phonophobia, are also
for a
migraine drug. But, in contrast to pain, these
symptoms are not always present in migraine
attacks
and, in fact, none of the Pozen studies
were
powered to detect differences for these
endpoints
but all were specified as secondary
endpoints in
our studies.
Nevertheless, significant differences in
the incidences of these symptoms were
seen among a
number of these studies at two hours
after dosing,
as shown now. In additional comparisons, shown in
yellow, the p-values were between 0.05
and 0.1.
65
The p-values, finally, in orange, are
above 0.1.
As is reviewed in your
briefing document,
by three or four hours after dosing,
significant
benefits on all of these associated
symptoms were
usually present with MT100 treatment.
So, to summarize, the totality
of the
evidence from these six studies clearly
shows that
MT100 is an effective acute treatment
for migraine.
(Slide CC-43)
I will now show the
comparisons of MT100
against naproxen sodium. These comparisons, again,
reflect the direct assessments of the
contribution
of metoclopramide within MT100 in order
to satisfy
the combination drug rule.
The two phase 3 factorial
studies were
each performed at sites in the U.S. Subjects were
randomized to treatment with either
MT100, naproxen
sodium 500 milligrams, or metoclopramide
16
milligrams, the identical doses of these
component
drugs that are contained within MT100.
Subjects treated a single
migraine attack
of moderate of severe pain intensity and
symptom
66
assessments were performed at baseline
and hourly
for 24 hours. Rescue medication was permitted
after at least two hours had elapsed
after dosing.
(Slide CC-44)
I would like to take a second
and explain
the pain assessments in these trials,
the primary
endpoint as well as the secondary
endpoints.
Sustained pain response at 24 hours was
agreed by
Pozen and the FDA as the appropriate
measure to use
to assess the efficacy of MT100 versus
each of its
two components.
Sustained pain response is a
composite
measure of efficacy and is defined as
pain relief
at two hours--that is, no pain or only
mild
pain--and no relapse or moderate or
severe pain and
no need for the use of rescue medication
over the
next 22 hours after the two-hour
assessment. The
efficacy of this endpoint is judged by
how many
subjects meet this definition at 24
hours.
I would like to stop at this
point and
explain why Pozen and the FDA agreed
that the use
of the two-hour pain response endpoint
would not be
67
acceptable for the comparison of MT100
with
naproxen sodium. This was because both treatment
are active due to the presence of
naproxen in each
drug and should, in fact, produce very
similar pain
responses at the time point of two hours
after
dosing.
Two-hour pain response was a
secondary
endpoint in these studies and was used
to evaluate
MT100 versus metoclopramide as a
pseudoplacebo, as
I have previously shown.
In contrast to the sustained
pain response
and two-hour response rates which
measure the
number of subjects responding, at the
bottom of the
slide, you will see three secondary
endpoints that
were also evaluated in these
trials. These are the
Pain Intensity Difference score, PID,
the Sum of
Pain Intensity Difference scores, SPID,
and the
TOTPAR scores, or Total Pain Relief
scores, over
time.
These are the measurements of
how much
pain relief is obtained, not of how many
subjects
have a specific pain response at a given
time.
68
These are the accepted general endpoints
for
analgesics within the FDA. They are recognized as
very sensitive for detecting differences
between
individual active analgesic drugs.
But let's first look at the agreed primary
endpoint and that was sustained pain
response from
these two studies.
(Slide CC-45)
Shown here are the data from
these studies
with a percent of responders
plotted. First, note
that the metoclopramide-alone treatment
produced
sustained pain response rates of 19 and
20 percent
which are similar to what might be
expected of a
placebo.
The responses to naproxen
sodium alone
were 9 to 10 percent higher than
metoclopramide and
the rates were actually 28 percent and
30 percent
in the two trials. These were significant
differences over metoclopramide. The
sustained
response rates for MT100 were 6 percent
and 4
percent higher than those for naproxen
sodium in
these two studies.
69
I am sure you have noted that
Pozen and
the FDA arrived at different p-values
for these
comparisons. But both parties agree that the
absolute differences are 4 and 6 percent
for this
endpoint. Are these differences confirmed by other
analyses? The secondary endpoints provide support
for these findings.
(Slide CC-46)
The mean SPID scores at 24
hours show
significant differences for MT100 versus
naproxen
sodium in both studies. So these analyses of a
secondary endpoint, a valid measure of
pain relief,
support the findings of the sustained
endpoint. I
would also note, and not shown, but the
fact that
the differences were significant in the
SPID scores
at two hours after dosing in both
studies.
(Slide CC-47)
A third dataset, the 24-hour
TOTPAR
scores, is also supportive with mean
TOTPAR scores
at 24 hours for these two studies
showing
significant differences between MT100
and naproxen
sodium.
So these additional analyses, which were
70
secondary, support and confirm the
results seen
with the sustained pain-response
endpoint and
substantiate the contribution of
metoclopramide to
the effect of MT100.
But, even if this were not the
case, there
is a subgroup pseudoplacebo that seems
to respond
much better to MT100 than the naproxen
sodium.
Now, the reason that we can discuss this
subgroup
is the following: at the outset of the
phase 3
program, Pozen theorized that
metoclopramide might
contribute not only to better pain
relief but might
also contribute to the relief of nausea
that may
accompany migraine attacks.
(Slide CC-48)
For this reason, one of the
three
pre-planned analyses that were used in
all of the
phase 3 studies include analyses of pain
endpoints
within two subgroups of migraine
attacks--that is,
those with nausea and those without
nausea at the
time of treatment.
(Slide CC-49)
These are the results for subjects
whose
71
migraine attacks were not accompanied by
nausea.
This type of migraine attack made up
one-third of
the attacks treated in Study 304 and
one-half of
the attacks treated in Study 301. The number of
subjects in each study is shown with the
figure on
the left being 301, the figure on the
right, 304.
In these subgroups of attacks,
the
differences between MT100 and naproxen
sodium for
sustained pain responses were
essentially doubled
to 9 and 10 percent. In this instance, the
differences were highly significant,
with p-values
less than 0.01 in both studies. This was seen in
both studies and, therefore, is not
likely to be a
chance occurrence.
Pozen took a further step of
providing its
phase 3 data to Drs. Richard Lipton and
Ken
Kolodner who conducted independent
analyses of
these data and confirmed these findings.
The odds
ratios and the significant p-values are
provided in
your briefing document in Table 11.
(Slide CC-50)
As additional confirmation,
the mean SPID
72
scores in these subjects with attacks
without
nausea also showed significant
differences in these
sensitive measures of pain relief for
MT100 versus
naproxen sodium at 24 hours. When Pozen met with
the FDA in late 2004 and the data for
this subgroup
of attacks were presented to the agency,
Pozen was
asked if the same effect was seen for
MT100 across
the phase 3 studies.
The answer is definitely yes. Pozen
performed a pooled analysis of phase 3
trial data
and these results were obtained.
(Slide CC-51)
These studies were conducted
in the same
time period. They all treated subjects with
migraine attacks of moderate to severe
intensity
and there were similar entry criteria
and
evaluation criteria. The comparators included
placebo, metoclopramide and naproxen
sodium.
As you can see, there was a
significant
difference only in the treatment with
MT100 for the
comparison of the treatment of attacks
with and
without nausea, again, highly
significant.
73
So why would these effects be
present?
The only plausible explanation is the 16
milligrams
of metoclopramide contained within
MT100.
(Slide CC-52)
Therefore, the unique
contribution of
metoclopramide may be described as
counteracting
the gastric stasis associated with
migraine,
enhancing the rate of absorption of
naproxen,
providing better pain relief in the
overall
treatment population and, finally,
enabling maximum
benefit to be obtained in migraine
attacks without
nausea.
(Slide CC-53)
So where does this leave the
efficacy of
MT100?
Pozen believes that the data show that
MT100 is an effective migraine
treatment, that
MT100 provides an absolute 4 to 6
percent
improvement in sustained pain response
over that
for naproxen sodium, that MT100 provides
absolute 9
to 10 percent improvements in sustained
pain
response over naproxen sodium in
migraine attacks
without nausea.
74
Secondary endpoints, SPID and
TOTPAR,
confirm the superiority of MT100 over
naproxen
sodium.
Finally, the contribution of
metoclopramide to the primary endpoint
of sustained
pain response is demonstrated in two
studies.
Thank you for your attention.
(Slide CC-54)
I would like now to
introduce--it is my
privilege now to introduce Dr. David
Matchar,
Professor of Medicine at Duke University
School of
Medicine. Dr. Matchar is Director of the Duke
Center for Clinical Health Policy Research
and,
over the past two decades, he has made
significant
contributions in the field of
evidence-based
decision making in medical care. In the migraine
area, he has been a member of the U.S.
Headache
Consortium and was lead author of the
group's
evidence-based guidelines for the
treatment of
migraine, a collaboration among eight
professional
societies.
Dr. Matchar was invited by Pozen
to
provide his perspective on the potential
role of
75
MT100 in the treatment of migraine and
his view on
the balance of benefits and risks of
this
treatment.
DR. KIEBURTZ: Just real quickly, any last
clarifying questions? Dr. Welch?
DR. WELCH: The nausea versus the
non-nausea studies. Was that a prospective nausea
versus non-nausea?
DR. ALEXANDER: The studies were both
designed to have a preplanned analysis
of the
subgroups of attacks with nausea and
without
nausea.
DR. WELCH: So you didn't look for
separate populations.
DR. ALEXANDER: I'm sorry; I
didn't
understand.
DR. WELCH: You didn't look for separate
populations. It was all in the same study.
DR. ALEXANDER: Oh; I'm sorry. It was the
same study. It was certainly not randomized
between nausea and no nausea.
DR. WELCH: Did you look at the time from
76
the start of the pain to the onset of the
nausea in
the nausea group?
DR. ALEXANDER: No; we didn't.
DR. KIEBURTZ: Dr. Temple.
DR. TEMPLE: Maybe you will think this is
too much discussion, but when you
separated out the
nausea people, my assumption always was
you thought
the drug would work better in people
that had
nausea, not less.
DR. ALEXANDER: That is exactly right. I
mentioned that--I may not have
emphasized it enough
because initially Pozen believed that
metoclopramide would have an anti-nausea
effect in
migraine. The thought was, we will look at those
with nausea and those without nausea.
We did that. As it turns out, if there is
an anti-nausea effect, it occurs after
two hours--
DR. TEMPLE: No; I don't even mean that.
You have said that the effect on pain is
better in
people with nausea.
DR. ALEXANDER: That's correct.
DR. TEMPLE: And you did, as you showed,
77
have groups with and without nausea
separated for
analysis. But what happened was the opposite of
what you expected. Maybe that is not a major
point.
DR. KIEBURTZ: Dr. Koski?
DR. KOSKI: I assume that your patients
within this study had more than one
attack of
migraine.
DR. ALEXANDER: That's not correct. This
was a single-attack study.
DR. KOSKI: It was single attack. Thank
you.
DR. KIEBURTZ: Dr. Goldstein.
DR. GOLDSTEIN: You may also want to defer
this question for later, but the
preparations that
you used in these comparator studies,
you went
through, or somebody went through, in
the beginning
talking about how the MT100 is put
together. You
have a core. Then it is sprayed and sprayed again,
and then there is another spraying on
top of that.
In these studies, how is the
metoclopramide put together? Was this done with a
78
blind core that was then sprayed in the
same way so
that the pharmacokinetics would be the
same?
DR. ALEXANDER: Yes; they were identical
in visual appearance and the
placebo--excuse me;
the comparators were identical and the
metoclopramide was around a core, a
blank core.
DR. GOLDSTEIN: Thank you.
DR. KIEBURTZ: Dr. Katz, did you have
something?
DR. KATZ: No.
DR. KIEBURTZ: Just to remind the sponsor,
we will stop in half an hour. Just if you want to
think about your presentations, we will
be stopping
at ten of the hour.
Potential Role of the MT100 in
Migraine Therapy
Balancing Benefits and
Risks
DR. MATCHAR: Good morning.
I think, in
addition to the introduction that Dr.
Alexander
gave me, I would just like to comment
that I am
also a principal investigator of the
three-city
study of headache management that is
funded by the
Agency for Healthcare Research and
Quality and that
79
is in an effort to link the
evidence-based
guidelines that have been developed to
actual
clinical practice. So it is in that context that I
will make my remarks this morning.
I guess, also parenthetically,
I should
mention that I am the husband of a
migrainer and
the father of a migrainer so I guess I
have both a
clinical, a research and also a personal
interest
in this topic.
(Slide CC-55)
My task that I have been asked
to fulfil
today is to talk about the clinical
trials and the
safety studies in a clinical-practice
context. In
thinking about this, three questions
really arose
in my mind that I felt were particularly
salient.
The first is is there really a role for a
new migraine therapy above and beyond
what we have
available. We have seven triptans that are out
there, for example. Do we really need something
else?
The second question is, when
we look at
clinical differences in clinical-trial
results of 4
80
to 6 percent, what, really, does that
mean to
patients. Is that something really worth pursuing?
Then the third question is how should we
be
thinking about benefit to risk in the
particular
scenario of an acute migraine treatment.
So, in talking about these
three
questions, or in addressing these three
questions,
I am going to follow the following
outline which is
first describing just some context of
the clinical
burden of migraine, efficacy in clinical
trials
focusing on the relationship between the
measures
and the meaning those measures might
have in a
clinical setting, and a little bit about
available
oral treatments including something
about adverse
effects of available treatments, and
then, finally,
talk a little more about this issue of
balancing
benefits and risks and a clinically
useful
conceptual framework that I have, I use,
and I find
useful in thinking about benefit and
risk.
(Slide CC-56)
Not to really belabor the obvious to a
group of neurologists about headache,
headache is
81
about pain. The definition from the International
Headache Society places pain as
key. It is an
episodic disorder lasting 4 to 72 hours
with two of
any of the following pain
characteristics;
unilateral location, pulsating quality,
moderate or
severe intensity and worsened by
movement.
In addition, there are the
associated
symptoms which were described earlier,
specifically
photophobia and phonophobia together or
nausea
and/or vomiting. So that constitutes a definition.
But, again, the key element from a
clinical
perspective, and from the diagnostic
perspective,
is pain.
(Slide CC-57)
It might go without saying
that migraine
is not a homogenous disease. While pain is nearly
always present, what is less consistent
is the
presence of associated symptoms. Here the
phonophobia or photophobia, the punch
line,
basically, is that most people typically
do have
these symptoms whereas, in the case of
nausea, most
people typically don't have nausea. So the data
82
here is only 38 percent reported nausea
or vomiting
in more than half of attacks and only 32
percent
reported nausea in all attacks. So that is just,
again, the point. The nausea is not uniformly
present and that migraine really is a
syndrome with
a variable syndrome cluster
presentation.
(Slide CC-58)
The question I am moving on to now
is the
issue of the unmet need. I don't know if anyone
cited the statistic of 25 million people
in the
United States having migraine. That is based on a
very high-quality epidemiologic study
done by
Richard Lipton and colleagues.
Of those 25 million, 53
percent of these
individuals describe a disability,
significant
disability, or the need for bed
rest. Now, I think
this is going to be described a bit
later, but
there needs to be some understanding of
the true
magnitude of a migraine for most
migrainers. These
are very severe headaches. They are very
disabling. In fact, a day is sliced out of that
person's life.
83
In addition to there being a
lot of
migrainers and the disability being
quite severe,
patients tend not to be satisfied with
their
treatment. We will go into that a little bit
later.
I will mention--I will expand a bit on the
issue of adverse effects, in particular,
but there
is good evidence that patients are not
getting
effective care in their early visits,
that
physicians are finding it difficult to
take the
medications that are available to them
and create a
mix that is useful to a large majority
of patients.
One of the issues at the
bottom here that
is cited, and I realize it is not a FDA
concern,
per se, but it certainly is a concern
for our
patients, is that the medications
available are
very expensive and often interfere with
patients'
willingness and ability to take them
regularly for
their severe attacks.
(Slide CC-59)
What do patients need? What patients
need, effectively, is what they
want. What do they
want?
They want pain relief. Again,
this is from
84
a survey done by Dr. Lipton and
colleagues.
Patients surveyed with migraine, they
say the most
desirable outcomes in an acute migraine
therapy are
rapid onset of pain relief, their
freedom from pain
and there is no recurrence of pain. So it is the
notion of a sustained response to pain
and
sustained response that goes into the
definition of
what patients are asking for from a
migraine
therapy.
(Slide CC-60)
Do clinical measures, or do
measures used
in clinical trials, address what
patients want?
Now, the standard measure that is used
in clinical
trials is the ordinal rating system in
which pain
is rated 3, 2, 1, 0 from severe to
none. It is
important to point out that 3 to 2 is
not
especially valuable for patients but
going from 2
to 1 is something that patients would
clearly
desire and, therefore, the criteria for
entry into
clinical studies would be having severe
or moderate
pain and the criteria for response is
going from
severe or moderate to mild or none.
85
So the measure that is
typically used, the
standard measure that has historically
been used,
is pain response rate. It is the proportion of
subjects who achieve mild or pain-free
status two
hours after dose when pain was either
moderate or
severe at baseline and no rescue
medications were
allowed in that period. But it is a two-hour
measure.
(Slide CC-61)
Let's turn to that other issue about
sustainability of the response. Let's start with
the measure I just mentioned which is a
good
measure.
It is a two-hour pain relief. It
is a
good start. Historically, it is what has been used
as the regulatory endpoint. Triptans, for example,
were approved on the basis of the
two-hour
response.
But a better response takes
into account
this time-course issue that patients
care about.
Sustained pain response at 24 hours
includes mild
or no pain at two hours, so it is what
the
preceding measure includes, but also
includes to
86
relapse to moderate or severe pain and
no use of
rescue medications. This means you get relief.
You continue to have relief.
Again, from a clinical
perspective, the
notion that you are not going to have a
recurrence
is
extremely important because the possibility of
having a recurrence is a very ominous
concern for
patients. If you know that there is a good
likelihood that this is going to come
back again,
you are not going to be able to
experience your day
in a normal way.
This also raises this concern
about, well,
is 5 percent more people having this
response
really worthwhile. I would suggest, well, if we
were only talking about 5 percent of
people, or 5
percent of pain, being better, going
from 100 to a
95, or going from 95 to a 90, that would
not be
particularly worthwhile.
But what we are talking about
is 5 percent
more people, so we are talking about
people, in
this case, they get relief and they
continue to
have relief. Again, this is a point of
87
differentiation that distinguishes MT100,
potentially, here.
At the bottom, I have here
what would be
considered the best outcome which would
be
sustained pain-free at 24 hours. I think this
constitutes our vision for what we would
like to
see in migraine therapy and I think we are
moving
towards that as a more standard measure
in future
clinical trials.
(Slide CC-62)
Briefly, on the issue of
associated
symptoms, we talked about the three
photophobia,
phonophobia and nausea. In clinical trials, these
symptoms tend to be more commonly
reported than
they are in community samples of
migrainers. But,
again, even in trials, these symptoms
are
associated only with a fraction of the
patients.
They are recorded as present
or absent so
the all-or-none measure is a relatively
crude
measure of response to treatment. Again, efficacy
is assessed at two hours which has a
concern from a
clinical perspective that some of these
patients
88
who won't have nausea at the outset will
start to
have nausea after and will have nausea
two hours,
but then might have it relieved at three
hours
after their pain is relieved.
So I think the point here
really is that
the measures of associated symptoms--it
is not that
associated symptoms aren't
important. They are
important. But the measures that tend to be used
and are standard in clinical trials are
relatively
crude and more so than the measures used
for pain.
(Slide CC-63)
So what do we have currently
for migraine
therapy that is oral and FDA-approved
for migraine
indication? What is currently available includes,
on the left side, the over-the-counters,
which are
ibuprofen, which are two products,
acetaminophen,
aspirin-caffeine combination. That is one side.
On the other side, and I would
say,
actually, far on the right side, are,
then the
prescription medications. There are seven triptans
currently FDA-approved for migraine and
the point
here is there is a paucity of approved
oral drugs.
89
I don't know any clinicians who would
say they are
particularly happy with the variety of
medications
that are available.
In light of the fact that most
patients
presenting to a doctor have failed
over-the-counter
medications for at least their worst
headaches,
then there really, truly, is a big gap
in what is
available when a patient presents to
you. In
effect, the only thing you have
available, as a
migraine-specific therapy in this case,
is going to
be the triptans.
I will mention in a moment
that that is
not always a satisfactory solution for
patients.
Unfortunately, what happens clinically,
when this
gap is not filled with another more
useful
medication, physicians are tending to
use--continue
to use--narcotics and barbiturates which
are
undesirable for lots of reasons, three
of which are
that they have not been studied in
clinical trials.
They are not FDA-approved, so that is a
concern.
And they, obviously, have undesirable
adverse
effects.
90
(Slide CC-64)
This clinical impression that
there is a
therapeutic gap is supported by empirical
evidence.
This is a couple of studies in which,
they point
out, in the real world, half of patients
will often
delay treatment with prescribed
medications. They
will have a prescription in hand and 69
percent of
them will wait and see if the headache is
really a
migraine. About half of them will want to take
their medication only if the attack is
severe.
This is not the sign of a very
healthy
environment, that people have
prescriptions and
they are not wanting to take them even
though they
are having, in this case, at least
moderate to
severe pain.
As a consequence, I would
presume, that
four out of five migrainers have
expressed an
interest, a specific interest, in trying
a novel
product with similar efficacy to what
they have in
hand, the prescription they have in
hand, but has
fewer adverse effects.
(Slide CC-65)
91
This then turns us to the
issue of
bothersome adverse effects. Why don't migrainers
like what we have available?
On the right side, you see the
non-triptan
products which include the
over-the-counters I
mentioned, nonsteroidals, but also
include opioids
and barbiturates. As one would expect, the side
effects are sleepiness, nausea,
difficulty
thinking, inability to function, and so
on.
Not too dissimilar, even, are
the triptans
on the left side. But one syndrome which is
particularly bothersome to many of my
patients--I
know it is extremely bothersome to my daughter--is
this chest-pressure phenomenon.
Yes; there are coronary
effects of the
triptan.
Some patients--and, indeed, it is
contraindicated with patients with
coronary-artery
disease--but, for the vast majority of
people who
are having these chest-pressure
syndromes, they
have no coronary disease. These are not coronary
symptoms. What they are, again, is a bit of
conjecture, but they are extremely
frightening and
92
most people who experience them find
them
sufficiently disturbing that, even if
you try to
convince them endlessly that they are
not having
cardiac ischemia, they are frightened
and they
won't want to take the medication.
So that is a concern and, as I
say, other
symptoms are sufficiently aversive for
patients
that they will delay their therapy or
not take the
medications prescribed at all.
(Slide CC-66)
Now let's turn to the issue of
balancing
benefits and risks of acute
therapy. To think
about this, I would like you to imagine,
first of
all, another scenario entirely. This other
scenario entirely is a stroke-preventive
medication.
A stroke-preventive medication
might work
and it might not work. How do you know that it
doesn't work? For
the most part, you know it
doesn't work because the patient has a
stroke.
Okay; you lose. And that is how you know that your
drug is a failure.
93
Well, we have a very lucky
circumstance
with migraine in that migraine lends
itself to
tailoring. There are multiple episodic attacks
over many years. You get immediate feedback on the
efficacy of the acute treatment. Tailoring here,
then, is specifically aimed at maximizing
the
chance that the therapy will work for a
given
attack.
The idea, basically, is
patients don't
like to take medications that don't
work,
especially if they don't have any other
effect that
you kind of like. So an opioid you might take even
if it doesn't really--well, not me,
personally, or
you, personally, but, certainly, some
people will
take them just because they have another
effect
that they like.
Consequently, with this
tailoring
occurring, the benefit-to-risk margin
actually
improves over time for each of our
individual
patients.
(Slide CC-67)
Recognizing that some people don't like
94
words as much as they like pictures, I
have here a
picture that basically raises this
concept as the
filter of clinical experience. We start out
basically saying, look, from population
studies,
from clinical trials, we realize that
not all
patients are going to respond. But we are going to
try it.
We are going to treat all these patients
within some set of characteristics.
We have some set of
characteristics and,
of course, it wouldn't have been
approved if we
hadn't considered the benefit-to-risk to
be
acceptable. Now, after some period of time,
patients decide this works under this
condition,
this doesn't work under this condition,
and they
pick and choose, and what we end up with
is
patients taking medications for which
they tend to
respond.
Consequently, the clinical
benefit-to-risk
ratio improves over time and is
ultimately
maximized. Again, the point I want to make is that
patients don't take drugs that don't
work for the
most park.
95
(Slide CC-68)
As suggested earlier, from the
experience
in the U.K., as Dr. Schapira mentioned
as well as
using the components in the United States,
the
notion is that MT100 would fill in this
gap that is
currently basically being filled with
opioids and
barbiturates which is a bad
scenario. The notion,
again, is that, amongst the various
options, what
we allow by making this new drug
available is to
fill in the gap and to offer an
opportunity for
patients to create a mix for themselves
that makes
the most sense for them.
Not all patients, certainly,
will respond
to
this. Those who will respond to it will
take
it.
The benefit, again, as I mentioned earlier, or
the risks, will only accrue to those
people who
achieve benefits.
(Slide CC-69)
So, in summary, I am going to
just cover
those three questions real quickly. Is there a
role for a new migraine drug? I believe the answer
is unequivocally yes. Migraine is a common
96
disorder. Patients have significant unmet needs.
The available oral medications are very
limited
and, unfortunately, the gap that exists
is now
being filled by undesirable drugs.
The second question is what is
the meaning
of the clinical-trial difference, this 4
to 6
percent everyone is talking about. Well, not
quibbling over whether you buy the 4 to
6 percent
statistical significance or not, what
does
5 percent mean. Let's just say 5 percent. 5
percent is not 5 percent of pain. It is 5 percent
of people. That is an important point from a
clinical perspective. That is meaningful.
Now, the last point, or the last
question,
is what is the meaning of a
benefit-to-risk ratio
in clinical practice. I just want to mention again
this concept of tailoring. Migraine treatment
lends itself to tailoring. Patients don't take
drugs that don't work and thus, in
clinical
practice, we have the lucky circumstance
that
benefit-to-risk ratios can be optimized.
Thank you very much.
97
DR. KIEBURTZ: Any--Dr. Sacco?.
DR. SACCO: Dr. Matchar, just a
clarification, maybe, on Slide 63 for
part of your
talk.
I assume most of your talk has been
indicated for acute migraine
attacks. You haven't
dealt with any of the FDA-approved
medications for
migraine prevention, of which there are
some.
DR. MATCHAR: Oh, sure; yes.
DR. SACCO: That would just be a
clarification.
DR. MATCHAR: Right.
These are oral
products for acute indication, acute
migraine.
DR. KIEBURTZ: Dr. Lenaerts?
DR. LENAERTS: Thank you.
I have a
question regarding Slide 57. Could you confirm the
38 percent of patients reporting nausea
and then 32
percent, actually, reporting in all
attacks. I
have some other information that says up
to 90
percent of people have nausea
occurring. So
migrainers have up to 90 percent.
DR. MATCHAR: Right.
The point that I am
making here has to do with the patterns,
the
98
typical patterns, for patients, not the
average for
all migraines. So having nausea
is a typical
pattern in a minority of patients. Actually, Dr.
Silberstein did one of these studies and
he might
be able to clarify that later.
DR. KIEBURTZ: Dr. Jeste.
DR. JESTE: I have a similar question. If
you look at your Slide 62, you said
nausea
incidence is 40 to 70 percent.
DR. MATCHAR: Right; and this is in
clinical trials. So the population you are going
to see in clinical trials is going to be
different.
So this says, basically, as a patient
enters into
these trials, the presence of nausea is
going to be
more likely than it was going to be when
you are
asking the question, what is the typical
pattern or
cluster of symptoms among
migrainers. So, yes;
patients who are in trials will
typically have the
symptoms more commonly.
DR. KIEBURTZ: Thank you.
DR. MATCHAR: I am going to turn to Dr.
Silberstein.
99
(Slide CC-70)
Dr. Silberstein is actually a
colleague
working on one of the clinical trials
that I
mentioned earlier and he is the Director
of the
Jefferson Headache Center and the
Department of
Neurology and is the President of the
American
Headache Society.
DR. KIEBURTZ: We see your number of
slides in the book, but just so you
are--
DR. SILBERSTEIN: I have cut them.
DR. KIEBURTZ: Perfect.
Thank you.
Clinical Considerations on
Migraine Therapy
DR. SILBERSTEIN: I want to thank
everybody for having us here today. Looking at the
time, I have tried to cut and I will try
to talk
reasonably quickly.
(Slide CC-71)
I am going to talk a little
bit about the
rationale for the use of metoclopramide.
I am
going to briefly talk about attacks
without nausea.
I am going to spend most of my time
talking about
medication-overuse headache of which I
have a
100
particular interest and then summarize a
possible
benefit of MT100.
(Slide CC-72)
We learned about
metoclopramide and
migraine many years ago from, actually,
our
colleagues in London. Marshall Wilkenson and Nat
Blau who run the City of London Migraine
Clinic
made it part of their everyday treatment
and it got
introduced, like many things do, on the
basis of
anecdote.
Many of us continue to use it in the
absence of trials until you saw the
evidence today.
It is used to prevent nausea. It enhances the
absorption of nonsteroidals. Many headache experts
continue to use metoclopramide for those
reasons.
(Slide CC-74)
I think you have seen the
evidence to show
that MT100 is more effective than
placebo. One can
argue about the statistics, but you see
in the
evidence that MT100 is more effective
than naproxen
sodium and clearly more effective than
metoclopramide.
101
(Slide CC-76)
One of issues is its 4 to 6
percent
response, clinically significant. I think, in
part, it depends on how seriously you
view migraine
as a disorder. If you had a patient who has had
cancer of the brain and you had a
survival rate of
10 percent and you went to 14 percent,
nobody would
argue that that is clinically
significant. So take
into context what migraine is to the
sufferer and
take into context that migraine is often
considered
not a serious disorder.
One of the ways of looking at
it is to
look at all attacks and look at the
absolute and
relative differences. If the 4 to 6 percent really
means in patients getting 14 to 20
percent relative
increase, and if you look at the subset
of attacks
without nausea, you are assuming that
the data is
correct because the subset analysis was
not the
primary endpoint, you are talking about
a third
improvement.
This, to me, is clinically
significant.
(Slide CC-78)
102
I would like to spend a little
bit of time
talking about the concept of
medication-overuse
headache, for that was one of the
questions. What
is it?
First, many patients have chronic daily
headache which, by definition, means
nothing more
than headaches occurring more than 15
days a month.
In the clinic, it is the most
common cause
of chronic daily headache. I was fortunate enough
to be the head of the International
Headache
Society Classification Committee on
Chronic Daily
Headache. The criteria we came up with were the
following: headache has to be there more often
than not greater than or equal to 15
days per
month; regular overuse for more than
three months
of acute medication; the headache is
actually
developed or worsened coexistent with
overuse;
lastly, you stop the overuse medication
and the
headache reverts to its previous form.
(Slide CC-79)
The next issue is how much
medicine.
First, triptans, ergots, opioids or
butalbital-containing analgesics taken
on a regular
103
basis ten or more days per month. What we don't
mean is ten days in a row. We mean ten days
divided up. Two, other analgesics 15 or more days
a month for a total exposure of 15 or
more days a
month.
That is the definition of
medication-overuse headache.
(Slide CC-80)
The next issue is which are
the drugs that
are most likely to produce
medication-overuse
headache. The first caveat is there are absolutely
no placebo-controlled, well-designed
clinical
trials of medication-overuse headache in
the world,
yet.
High probability based on a series of
anecdotes, opioids or narcotics,
ergotamine and
butalbital-containing compounds.
Chris Diener from Germany said
the best
thing he ever did was get
butalbital-containing
compounds removed from the market in
Germany. That
is his legacy.
Caffeine is associated with
medication-overuse headache. Lower probability;
aspirin, acetaminophen, and
triptans. Unlikely and
104
controversial, other non-steroidals, DHE
or
neuroleptics are even associated with
medication-overuse headache.
(Slide CC-81)
In summary, MT100 in migraine
therapy. I
think it could be a primary therapy when
simple
analgesics fail. By the time patients come to the
physician, they have failed simple
analgesics and,
as Dr. Matchar showed, there is an area
in between.
Triptans can't be used, don't work or
are overused.
The reason for this is, we
believe, that
nonsteroidals and neuroleptics,
metoclopramide, in
particular, are unlikely to produce
medication-overuse headache. It is common among
clinicians who are interested in
headache--we use
this class of drugs to prevent
medication-overuse
headache or to treat medication-overuse
headache.
Lastly, we believe it can fill the gap
between
simple analgesics and triptans that is
now being
filled by opioids and by
butalbital-containing
compounds.
(Slide CC-82)
105
I think it is important to
realize the
World Health Organization has said that
migraine is
one of the four most disabling disorders
know to
mankind and that a patient with a severe
migraine
attack has the same degree of disability
as
somebody who has quadriparesis, dementia
or acute
psychosis.
Thank you.
DR. KIEBURTZ: Thank you.
Any clarification
questions? Dr. Temple?
DR. TEMPLE: One of your slides, and a
number of people have shown the same
one, was the
attractiveness of oral metoclopramide in
migraine.
DR. SILBERSTEIN: Correct.
DR. TEMPLE: Counteracting gastric stasis.
DR. SILBERSTEIN: Correct.
DR. TEMPLE: Treating or preventing
nausea, enhancing absorption of NSAIDs
and a lot of
people use it.
DR. SILBERSTEIN: Right.
DR. TEMPLE: I guess what are you saying
about those things? Are you saying that is part of
106
the evidence? Or what?
DR. SILBERSTEIN: What I am saying is the
following. Until these trials were done, we were
doing this on anecdote. Physicians continue to do
a number of things in the absence of
evidence-based
medicine. I think what you have seen today is
evidence-based medicine. I think the questions are
going to be, there are a lot of patterns
of
behavior. The pattern of behavior in the United
States today for taking care of most
migraine
attacks is to either give a narcotic or
opioid or
butalbutal-containing in the absence of
scientific
evidence.
What I am suggesting is this
is an
alternative and I think it is the job of
this panel
to see whether it is a good or a bad
alternative.
DR. TEMPLE: Okay.
But you are not
suggesting any of those reasons are the
reasons or
true or--
DR. SILBERSTEIN: I am suggesting that
this is the anecdotal lure and the basis
of why
this compound has been commonly used in
the past in
107
the absence of good scientific evidence.
DR. TEMPLE: Okay.
DR. KIEBURTZ: Thank you.
We will break now for fifteen
minutes. I
will just remind the committee members
that our
discussions only happen in public. During the
break, you are not to discuss with other
committee
members or, in fact, anybody, the
presentations or
your views on things. The point of having a public
meeting is our discussions are
public. So, just
avoid that in the interim and we will
start at
10:05.
Thank you.
(Break.)
DR. KIEBURTZ: Why don't we get started.
Dr. Bastings will be our first
presenter, the
clinical team leader. We will have, just to
clarify the agenda, about an
hour-and-15-minute
presentation from FDA including an invited
speaker.
Then we will have time to question, for
the
committee to question, both the sponsor
and the
FDA.
108
Some of the questions I kind
of suppressed
earlier about interpretation, context,
and so
forth, that is our opportunity to do
that.
So, Dr. Bastings, please.
FDA Presentations
FDA Risk/Benefit
Considerations
DR. BASTINGS: Thank you.
Good morning.
(Slide 1)
I will now present you some
FDA
risk/benefit considerations for MT100.
(Slide 2)
As you know, MT100 is a combination
of
naproxen sodium 500 milligrams and
metoclopramide
hydrochloride 16 milligrams. The proposed
indication is the acute treatment of a
migraine
headache with or without aura.
The division issued a
not-approvable
action in May, 2004 mostly because the
review team
determined that the contribution of both
active
drug components to the claimed effects
of the
product had not been established.
(Slide 3)
109
According to the FDA
Combination Policy,
two or more drugs may be combined in a
single
dosage form when each component makes a
contribution to claimed effects and the
dosage of
each component is such that the
combination is safe
and effective for a significant patient
population
regarding such concurrent therapy.
(Slide 4)
To address the Combination
Policy
requirements, Pozen conducted two
factorial studies
of similar design. These were Study 301 and 304.
In both studies, patients were
randomized to MT100,
naproxen or metoclopramide. The primary endpoint
was sustained pain response.
(Slide 5)
Sustained pain response is
defined as a
moderate or severe headache at baseline
with mild
or no headache at two hours and no
relapse and no
use of rescue medication between two and
24 hours.
(Slide 6)
This slide shows you the key
result of the
two factorial studies. For Study 301, the
110
sustained response rate for MT100 was 35.6
percent
as compared to 29.8 percent for
naproxen. So the
contribution of metoclopramide was 5.8
percent and
this was not a statistically significant
difference
according to the prespecified analysis
plan.
For Study 304, which was a
much larger
study, the sustained response rate for
MT100 was
31.8 percent as compared to 27.9 percent
for
naproxen. So the contribution of metoclopramide
was 3.9 percent and this was not a
statistically
significant difference according to the
prespecified analysis plan.
(Slide 7)
This slide shows you the
two-hour
endpoints in the factorial studies. I must stress
that Pozen was not required to show a
contribution
of metoclopramide on these
endpoints. However,
these are highly relevant endpoints in
migraine
studies.
These are the ones typically used to
approve migraine drugs. Since the primary endpoint
did not show a significant contribution
of
metoclopramide, it is useful to examine
these
111
typical endpoints.
What you can see on this slide
is that, in
both studies, there was no significant
difference
between MT100 and naproxen for the
two-hour pain
response, the incidence of nausea at two
hours, the
incidence of photophobia at two hours
and the
incidence of phonophobia at two hours.
(Slide 8)
As you know, sustained pain
response is a
composite endpoint. To better understand the
changes seen with that endpoint, it is
useful to
look at the individual components which
are the
two-hour pain response and the use of
relapse or
rescue medication.
So, in Study 301, you can see
that the
two-hour response for MT100 was 48.1
percent as
compared to 46.6 percent with
naproxen. So the
contribution of metoclopramide at two
hours at 1.5
percent.
This was not statistically significant.
The use of rescue medication
or the
relapse of the headache after a response
at two
hours was seen in 12.6 percent of MT100
patients
112
versus 16.8 percent of naproxen
patients. So the
contribution of metoclopramide there was
4.2
percent and this adds up to 5.8 percent
of
difference in the sustained response
rate.
(Slide 9)
In Study 304, you can see a
contribution
of metoclopramide for the two-hour pain
response of
3.1 percent and you see that the
difference in the
relapse or rescue-medication use is less
than 1
percent.
This adds up to 3.9 percent of difference
in the sustained response rate.
(Slide 10)
Finally, this slide shows the
sustained
responses for the associated
symptoms. Sustained
responses here are defined in a similar
manner as
for sustained pain response. For example,
sustained nausea-free means no nausea at
two hours
with no relapse of nausea between two
and 24 hours
and not use of rescue medication.
What you can see is that, in
both studies,
there was no significant difference
between MT100
and naproxen for sustained nausea-free,
sustained
113
photophobia-free, and sustained
phonophobia-free.
(Slide 11)
Pozen met with the division in
October,
2004, and, at that time, they presented
these
subgroup analyses which suggested a
contribution of
metoclopramide in patients with no
nausea at
baseline. At that time, the division considered to
accept the prospective replication of
these
findings to fulfill the Combination
Policy
requirements but we assured Pozen that
we would
need to bring this to an advisory
meeting because
this is an unusual patient population
and we need
to make sure the benefits in that
population
outweigh the risk related to
metoclopramide.
(Slide 12)
I will briefly show you these
subgroup
analyses that Pozen made. You already know that,
for the combined patient population,
there was no
significant difference between MT100 and
naproxen
for sustained pain response and for the
two-hour
pain response.
If you look at the patients
who did not
114
have nausea at baseline, you see about
10 percent
difference between MT100 and naproxen
with a low
p-value.
But, if you look at the two-hour pain
response, there was no significant
difference
between MT100 and naproxen even in that
subgroup.
For patients who had nausea at
baseline,
you can see that there was less than 1
percent
difference between MT100 and naproxen for
sustained
pain response. For the two-hour pain response, the
rate was actually numerically higher for
naproxen
but the difference was not statistically
significant with MT100.
(Slide 13)
Similar findings for Study 304. You know
that, for the combined patient
populations, there
was no significant difference for
sustained pain
response and two-hour pain
response. For patients
with no nausea at baseline, again, there
is about a
10 percent difference between MT100 and
naproxen.
For the two-hour pain response, there is
no
significant difference between MT100 and
naproxen
for that subgroup.
115
For patients with nausea at
baseline,
there was about a 1 percent difference
between
MT100 and naproxen for sustained pain
response and
the two-hour pain response. These differences were
not statistically significant.
(Slide 14)
I would like to give you some
thoughts on
an indication limited to patients with
no nausea at
baseline. In a survey of 500 self-reported
migrainers, nausea occurred in more than
90 percent
of these patients and nearly one-third
of these
experienced nausea during every attack.
Less than 10 percent of
patients
consistently had migraine with no nausea
at
baseline which is the indication for
which MT100
which is being considered today. In line
with that
survey, there was a 45 to 69 percent
incidence of
nausea at baseline in the MT100 phase e
studies.
(Slide 15)
Migraine patients, in the
majority of
them, may have some attacks with nausea
and other
attacks without or nausea may develop
during the
116
attack.
Patients would, therefore, need two
different treatments based on the
presence or
absence of nausea or they would treat
their attacks
with nausea with a combination product
containing
metoclopramide which has no established
contribution for efficacy for the type
of attack.
Yet, they would be exposed to the risk
of
metoclopramide.
(Slide 16)
As you know, our main safety
concern is
tardive dyskinesia. Tardive was originally
intended to emphasize a late appearance
during
neuroleptic treatment. However, there have been a
number of reports that TD may appear
early during
the neuroleptic treatment and there
seems to be no
fundamental distinction between cases appearing
early and those appearing late.
(Slide 17)
In addition, there have been a
number of
TD variants described and these include
tardive
dystonia, tardive akathisia, tardive
myoclonus,
tardive tics, tardive tremor, and it is
very much
117
unclear how well these different
variants have been
captured in the post-marketing reporting
systems.
(Slide 18)
TD is a well-known side effect
of
metoclopramide. Its exact incidence remains
unclear.
There was no case reported in the MT100
database but the database was too small
to detect
rare events such as TD.
(Slide 19)
The current metoclopramide
labeling
includes a warning which I am going to
read to you.
"Tardive dyskinesia may develop in
patients treated
with metoclopramide. Although the prevalence of
the syndrome appears to be highest among
the
elderly, especially elderly women, it is
impossible
to predict which patients are likely to
develop the
syndrome. Both the risk of developing the syndrome
and the likelihood that it will become
reversible
are believed to increase with the
duration of
treatment and the total cumulative
dose. Less
commonly, the syndrome can develop after
relatively
brief treatment periods at low
doses. In these
118
cases, symptoms appear more likely to be
reversible."
(Slide 20)
Because of these safety
concerns, the FDA
limited the indication of oral
metoclopramide for
short-term therapy for gastroesophageal
reflux for
up to 12 weeks and only when
conservative treatment
fails for the treatment of diabetic gastroparesis
for up to eight weeks. The recommended dose is 5
to 15 milligrams up to four times a day.
(Slide 21)
As I mentioned earlier, there
have been a
number of cases reported in the literature
of the
relatively short durations of treatment,
sometimes
as short as one or two weeks. We also asked our
colleagues from the Office of Drug
Safety to look
for cases of movement disorders
associated to
metoclopramide in the AERS database and
you will
hear a presentation with much more
detail on that
topic later in the morning.
In that analysis, the first
quartile of
duration of treatment for the cases of
TD was 19.5
119
days.
(Slide 22)
This slide show you a
breakdown of the
treatment duration. You can see that there are
quite a few cases with duration of
treatment less
than the 90-day definition which has
been used in
some of the earlier studies.
(Slide 23)
We also asked our colleagues
from ODS to
look at the patterns of use of
metoclopramide.
Metoclopramide is mostly used for GI
indications.
Migraine use, up to now, is quite
limited. It is
less than 2 percent. 13 percent of patients
appeared to have received prescriptions
for more
than 90 days and 7 percent of patients
for more
than 180 days, so exceeding the labeling
recommendations.
Over a three-year period,
cumulative
therapy was longer than 90 days for
almost 20
percent of patients and greater than 180
days for
over 10 percent of patients, again
exceeding the
recommendations.
120
(Slide 24)
What about the risk of TD
associated with
chronic intermittent use of
metoclopramide as has
been proposed in this NDA. This is very difficult
to evaluate for a variety of reasons
which include
that there is no current indication for
chronic
intermittent use in the United States
and that
there is no specific capture of chronic
intermittent use in the AERS database.
Some animal data suggests that
the
intermittent use of neuroleptics may be
no safer,
or even riskier, than continuous use in
an animal
model of TD. In the psychiatric population, the
number of interruptions in chronic
treatment--so
this is slightly different from chronic
intermittent but this may be
suggestive--the number
of interruptions was the second factor
after age in
predicting the occurrence of TD.
(Slide 25)
Another concern that we have
is the
overuse of acute migraine drugs.
Medication-overuse headache was recently
introduced
121
in the IHS classification. There is a subcategory
of analgesic-overuse headache. According to
experts, there is substantial evidence
that all
drugs used for the treatment of migraine
may cause
medication-overuse headache and the
prevalence of
medication-overuse headache in the
general
population is around 1 percent.
The IHS also said that the
overuse of
symptomatic migraine drugs is the most
common cause
of chronic daily headache. We are not that much
worried that MT100 could cause chronic
daily
headache. We are just worried that there could be
a similar abuse of the drug as has been
seen with
the other approved or non-approved
migraine drugs.
(Slide 26)
So we have the following
questions for the
advisory committee. The first one; in a recent
submission to the NDA, Pozen estimated
an annual
incidence of TD of up to 0.038 percent
for
metoclopramide at a daily dose of 30 to
40
milligrams per day for 72 days per year
which
corresponds to up to 380 cases of TD per
million
122
patients per year.
Do you think that this is a
reasonable
estimate? If MT100 were to carry the same risk,
would such a risk level be acceptable if
the only
contribution of metoclopramide is a 5 to
10 percent
improvement on sustained headache relief
with no
effect onto our endpoints? Is any risk of TD
acceptable for a migraine population?
(Slide 27)
Question 1; is there
sufficient evidence
that the chronic intermittent
administration of
metoclopramide does not carry a risk of
TD? Is it
possible to define a maximum recommended
number of
monthly doses of MT100 to avoid the risk
of tardive
dyskinesia?
(Slide 28)
Question 3; do you believe
that, based on
the existing data on medication-overuse
headache,
there is evidence that a proportion of
patients
prescribed MT100 will likely take a
number of
monthly doses higher than recommended?
(Slide 29)
123
Question 4; all currently
approved acute
treatments of migraine are indicated
without
restriction regarding the presence of
absence of
nausea at baseline. Given that patients may have
nausea at some attacks and no nausea at
others,
does an indication limited to the subpopulation of
migraine patients with no nausea at
baseline
represent a clinically meaningful and
acceptable
indication?
(Slide 30)
The last question; if Pozen
shows
prospectively in a new clinical study in
migraine
patients with no nausea at baseline a
significant
contribution of metoclopramide on
sustained
headache pain relief of 5 to 10 percent
with no
contribution at two hours and no
contribution on
relapse rates or rescue-medication use
in the two
to 24 hour period, would the
demonstrated benefit
outweigh the risk related to TD? If not, what
additional data or desired primary outcome,
or
desired effect on sustained relief,
could provide
evidence of safety and efficacy?
124
(Slide 31)
Finally, I would like to thank
the
following FDA colleagues who have
contributed to
this presentation . Thank you for your attention.
DR. KIEBURTZ: Thank you.
Same deal. If
there are some clarifying
questions. Let me just
point out some things about the
questions which Dr.
Bastings has presented. After the public hearing
this afternoon, that will be the time we
have to
spend a great deal of time discussing
these.
We can clarify points of these
questions
at that time rather than at this time
because it
will be immediate to our discussion.
I would just add at this point
my approach
to this, or our approach to this, should
be that
there are some assumptions made in
here. We are
not debating whether those assumptions
are good
ones or bad ones. The question to us is, if that
was assumed, how would you think. This is what Dr.
Katz referred to earlier in terms of this
being
somewhat hypothetical.
I think we could spend a lot
of time
125
arguing about whether the assumptions
are good ones
or not.
I don't think that is the meat of the
matter here. If one assumed those things, then how
would you make decisions about
that. I just want
to put that out there.
There are some questions that
are asked of
us about estimates and whether those are
reasonable. But, again, much of the clarification
on the questions, I think it would be
better to do
at the time we discuss the questions
individually
unless you have a burning question about
those.
Certainly, they are open to questions
about the
rest of Dr. Bastings' presentation.
Dr. Green.
DR. GREEN: I have a regulatory question
about the Combination Policy. It has to do with
the contribution of each drug and what is
acceptable. Is one drug increasing the
bioavailability of another? How would that be
interpreted?
DR. KIEBURTZ: Dr. Katz or Dr. Bastings?
DR. KATZ: I think the contribution, as
126
defined in the reg--it is ill-defined in
the reg.
It just says "some
contribution." So it could be
in any one of a number of clinical
areas, safety,
efficacy. But, in and of itself, increasing the
bioavailability probably wouldn't be
particularly
helpful unless that resulted in some
sort of
clinical advantage; faster onset, or
more sustained
onset, or fewer side effects.
So, in and of itself,
increasing the
bioavailability in a typical case, at
least off the
top of my head, wouldn't be,
necessarily,
considered useful.
DR. TEMPLE: But you can imagine cases,
and there have been cases, where
inhibiting
metabolism might lead to a more sustained and less
variable blood level. In some sense, what does
carba dopa do? So there could be cases. But, as
Russ says, you would have to weigh the
disadvantage
of adding another therapy and, if the
alternative
is just tasking 20 percent more, you
would probably
find that not worth it.
DR. KIEBURTZ: Okay.
Why don't we go on.
127
Our next speaker is Dr. Jinnah from
Johns Hopkins
Hospital.
Overview of Tardive
Dyskinesia
DR. JINNAH: Good morning.
(Slide)
Thanks for the invitation to
come and
speak here. I have been asked to give a brief
summary of the clinical condition of
tardive
dyskinesia.
Normally, my presentation on
this topic
would be about an hour, but I am going
to limit my
comments to ten minutes and, in so
doing, I am only
going to be able to touch on the
highlights. I am
going to skip a lot of details but I can
certainly
answer questions later if necessary.
(Slide)
So, with that, let me just
proceed to
review this topic. The term "dyskinesia" refers to
any abnormal movement and the term
"tardive" refers
to late or delayed. What I would like to do is
first address the nature of the abnormal
movements
and then go on to describe when it
occurs.
128
(Slide)
The movements vary quite a bit depending
on different patients. By far the most common
abnormal tardive syndrome is the
so-called
buccolingomasticatory syndrome, which is
a bit of a
mouthful, but it basically refers to abnormal
movements of the face and tongue. I will show you
an example of this on videotape in just
a second.
Less common tardive movement
disorder
syndromes include the ones listed there
including
tardive dystonia, which refers to mainly
twisting
and bending movements, tardive chorea,
which
resembles dancing, tardive tourettism
which
resembles Tourette syndrome, tardive
tremor or
myoclonus which, simply put, are shakes
and jerks.
In addition to this group of
broader
movement disorders, there are some
tardive
syndromes that are not necessarily
classified as
abnormal movements but, rather,
psychological or
psychiatric manifestations. These include
akathisia, which is a sense of severe
restlessness
that prevents people from sitting
still. It
129
includes unusual tardive pain syndromes
which have
an unusual anatomical distribution that
include the
oral or perineal regions, and, finally,
respiratory
irregularities referred to as tardive
respiratory
dyskinesias.
Now, most clinicians will
recognize the
most common form here and that is the
top one, the
face-and-tongue syndrome. But the less common
forms are far less well appreciated.
(Video)
Let me show you an example of
two of
these, first the most common one. This is a
videotape of a man who has two
problems. I hope it
is not too small to see. If you can see his mouth,
it is in constant motion, jaw, lips and
tongue. He
came complaining that he had trouble
talking, he
had trouble eating and he was biting his
tongue.
You can also see his
hand. One of his
hands is shaking. He has a tremor that resembles
Parkinson's disease. This man got his condition
after two years of metoclopramide use. He was,
unfortunately, unaware that he was only
supposed to
130
be taking the medication for three
months and his
doctor was unaware that metoclopramide
was on the
list of medications that can cause a
tardive
syndrome like this.
(Video)
Let me show you a second
example of the
tardive dystonia. You can see this man's problem
is much more severe and, perhaps, more
disabling.
This is an example of dystonia or the
bending-and-twisting syndrome. You can see that he
has great difficulty standing up
straight because
of extreme arching of his back and
backward bending
of his head and neck.
Here you will see a closer
view of the
nature of this problem. He is like this more than
80 percent of his waking hours, standing
or seated.
He gets relief only if he lies
down. He can only
temporarily bring his head to the
midline position
voluntarily and then it just goes back
and it is
too much effort to keep straight.
This man got his condition
from the use of
a classic neuroleptic agent which is a
more common
131
source of this problem.
(Slide)
So what exactly causes these
syndromes?
It
is widely recognized that they are most commonly
caused by the neuroleptics. These are the
dopamine-receptor-blocking agents that
Dr. Schapira
alluded to in the initial presentation.
Essentially all classes of neuroleptics
will cause
this syndrome although some are less
likely to
cause it than others.
These are widely recognized
but what is
less well recognized is a much longer
list of
agents that also have the potential to
cause these
syndromes. On this list include anti-emetics such
as metoclopramide and
prochlorperazine. Other
medications used in psychiatry such as
anti-depressants and several others of
which I have
provided a partial list here.
(Slide)
So when do these problems
actually arise?
They are referred to as tardive
syndromes because
they usually require chronic
administration of the
132
offending drugs. They occur with a wide range of
prevalence according to different
studies from less
than 5 percent to more than 50 percent
with an
overall average being somewhere in the 20
percent
range of chronically treated patients.
These numbers here were not
derived
specifically from metoclopramide use but
rather
from all neuroleptics and other drugs
capable of
causing tardive syndromes. The incidence is
estimated to be about 5 percent per year
during
chronic daily treatment. The treatment duration is
somewhat arguable and varies from report
to report
and definition to definition. The most
conservative one is that treatment
requires at
least three months of constant therapy.
But, as noted before, there
are lots of
cases out there who have developed
tardive
syndromes with much shorter durations of
action,
sometimes just a few days. We can then ask whether
or not these disorders should be
classified as
tardive syndromes or not, but that is
generally not
done in most of the epidemiological
reports or
133
collecting databases.
There are some known risk
factors of
developing this condition. They include older age,
female gender and several other less
well-understood phenomena such as
duration of
treatment, the total cumulative dose of
treatment,
prior brain injury or other organic
problems,
diabetes, mood disorders and others.
(Slide)
How are these treated once
they arise? In
general, these recommendations come from
psychiatry
where this problem is most
prevalent. They refer
to all neuroleptics, not specifically to
metoclopramide. Generally speaking, the
recommendation is to attempt to
discontinue the
offending agent if possible.
If it is not possible, or if
discontinuation does not cause
resolution of the
syndrome, as it often does not, there
are several
other things that are often tried, but
there is
very little evidence supporting a
beneficial effect
of any of these. Individual patients may respond
134
somewhat to one or another of the items
on this
list, but, by no means, can these be
considered
reliable treatments.
Instead, at least in the
psychiatry
literature, the belief for the use of
neuroleptics
and related offending medications that
can cause
tardive syndromes is that prevention
should be one
of the key aspects of treatment.
To prevent the disorder, the
general
guidelines are that the neuroleptics
should not be
used unless there are no other
alternatives. When
they are used, they should be used at
the lowest
dose possible. Some even recommend intermittent
withdrawal of the neuroleptic to make
sure that
ongoing therapy is still needed. Since this
disorder is quite difficult to treat,
prevention is
really quite an important element.
I believe that is all I have
here and if
there are any questions, I could take
them.
DR. KIEBURTZ: Dr. Jeste.
DR. JESTE: One question.
Did you imply
that antidepressants and antibiotics
cause tardive
135
dyskinesia?
DR. JINNAH: Causation is difficult to
establish. If you look in the literature, you will
find many cases of tardive dyskinesia
reported that
are due to a whole variety of different
medications. The frequency of some of these other
medications--for example,
antidepressants or
antibiotics, or I should say the
frequency of the
reports, is quite low. We could argue whether or
not the patients who were presented in
those
reports really were tardive dyskinesia
or not.
I am not passing judgement on
the
diagnosis of those. But I think it is generally
well-accepted that tardive dyskinesia
does not just
come from neuroleptic medications and
that was my
point.
DR. JUNG: Can you clarify what
mood
disorders are associated with the
development of
tardive dyskinesia?
DR. JINNAH: There appears to be a slight
epidemiological risk associated with
affective and
schizo-affective disorders as opposed
to, for
136
example, schizophrenia.
DR. JUNG: So that includes just general
depression which is very prevalent in
the
population.
DR. JINNAH: It does.
DR. JUNG: Thank you.
DR. SMITH: When a case comes up where
isn't chronic exposure to a drug, is
that typically
categorized, then, as a dyskinesia as
opposed to a
tardive dyskinesia?
DR. JINNAH: It is a very good question.
I think different experts would answer
you
differently here. Some people use a very strict
criteria that it has to be at least 30
days or you
call it something else, dyskinesia and
acute
abnormal syndrome. Some people are a little bit
less strict in their criteria and say,
well, if it
looks and behaves like tardive
dyskinesia, then,
perhaps, one week exposure is sufficient. But these
are not generally agreed-upon
timetables.
DR. JUNG: You didn't talk about this on
your slides, but could you discuss a
little bit
137
about the kindling phenomenon with
intermittent
use, or is this an appropriate time?
DR. KIEBURTZ: Can we hold that one for
the general question session.
Dr. Sacco?
DR. SACCO: On Slide 3, I think it is
Slide 3 of yours, can you clarify what
you mean
by--it is actually blurred on my
page--restlessness.
DR. JINNAH: Restlessness is exactly what
that sounds like. These patients report that they
can't sit still. When you watch them, they often
rock in their chair. They stand up. They pace
around.
They just can't sit still and they
describe a severe inner sense of
restlessness.
DR. SACCO: Thank you.
DR. KIEBURTZ: Just a point of
clarification, a follow up on Dr.
Jeste's comment.
Linking exposure to a phenomenon or
establishing
causation is a long road. There are various
degrees of that road being established
for various
agents in tardive dyskinesia.
138
But, if I understood you
properly, would
you say that it is generally accepted
that
metoclopramide, as an agent, can cause
tardive
dyskinesia?
DR. JINNAH: I believe most would agree
with that.
DR. KIEBURTZ: Thanks.
Our next speaker is Mary Ross
Southworth.
Post-Marketing Review of
Movement
Disorders and Neuroleptic
Syndrome
Associated with
Metoclopramide
DR. SOUTHWORTH: Good morning.
(Slides 1 and 2)
As we have heard this morning,
MT100 is a
combination of metoclopramide and
naproxen that is
being evaluated for the treatment of
acute
migraine. The proposed dosing is an a chronic but
intermittent matter based on episodes of
migraine.
The proposed dosing of the drug
recommends no more
than six tablets be used per month and
more than
one tablet used per single migraine
episode.
We were interested in looking
at this
139
chronic intermittent dosing, whether we
could look
in our adverse-event database to see
whether we
could elucidate the risks associated
with this kind
of dosing.
(Slide 3)
I think we are pretty clear on
the fact
that metoclopramide is well known to
cause movement
disorders. In fact, the program labeling is
specific on several movement disorders
including
extrapyramidal symptoms, Parkinsonian
symptoms,
tardive dyskinesia and neuroleptic
malignant
syndrome. The labeling for metoclopramide
recommends a daily dose of 5 to 20
milligrams QID
with a duration of therapy not exceeded
12 weeks.
(Slide 4)
This slide shows number of
prescriptions
dispensed for metoclopramide over about
the last
ten years. You can see that it exceeds 7 million
in the year 2004. This jump in number of
prescriptions dispensed in 2000
coincides with the
withdrawal of cisipride from the market.
You have to keep in mind that
the numbers
140
represented here are prescriptions
dispensed, not
patients. Also keep in mind that, although this
usage data slide only extends for ten
years, my
adverse-event review will extend farther
than that.
(Slide 5)
When developing our case
series for
metoclopramide-associated movement
disorders and
neuroleptic malignant syndrome, we
wanted to focus
on several points. First, could we ascertain what
the reversibility of the reaction was,
whether it
be treatment with another pharmacologic
agent or
withdrawal of the offending drug.
We also were very interested
in
associating the dose and duration
reported in the
adverse-event reports, themselves, to
the proposed
dosing for MT100 which, as you have
heard, is in a
chronic intermittent manner. We also wanted to
focus on any associated risk factors
that were
apparent in the cases such as concomitant
drugs or
concomitant disease states that the
patients might
experience.
(Slide 6)
141
So the purpose of our review
is to
characterize the cases of some specific
adverse
events that were reported in the
adverse-event
reporting system, or the AERS database,
that were
associated with metoclopramide.
(Slide 7)
The AERS database is a
computerized
database which contains reports of
adverse events
for all U.S. marketed drugs. It contains over 3
million adverse-event reports. The reporting in it
is largely spontaneous meaning that
healthcare
providers are not compelled to report
adverse
events.
However, sponsors, when they become aware
of adverse events through a variety of
sources, are
required by regulations to report those
to the
agency.
Consequently, the source of
the reports,
for the most part, come from
sponsors. However,
there are a good number that come from
healthcare
providers or lay people like consumers,
patients,
patient's families or lawyers.
(Slide 8)
142
The left side of the screen
shows the
adverse events that were specifically
searched for
in
our database. They included neuroleptic
malignant syndrome, acute dystonia,
akathisia,
Parkinsonism and tardive
dyskinesia. For each of
these adverse events, we looked at the
total number
of case reports with specific focus
given to daily
dose of metoclopramide, the duration of
treatment,
any risk factors that might be present
and the
reversibility of the reaction.
(Slide 9)
In order to do this, we ran a
search of
the database using each of the movement
disorders
and NMS as a search term plus
metoclopramide. We
classified the cases into
movement-disorder
categories based on the diagnosis in the
case,
itself.
I think it is pretty clear that there is
substantial overlap between some of the
reporting
of the different movement disorders and,
in order
to keep clarity, we just used the
diagnosis that
was used of the case thinking we could
capture the
most number of cases that way.
143
Some points to remember when
reviewing our
case series were there could be what
could be
considered case misclassification
because some
cases might have reported a movement
disorder after
several doses of drug but may have
caused the
tardive dyskinesia where it could have
possibly
been called an acute dystonia. But we used the
diagnosis made in the case.
Another thing to remember is
that the way
cases are reported in AERS, we
frequently know
dose, duration or frequency of the dose
given but
we very rarely know whether the dose was
given
continuously or intermittently.
Obviously, because these are
labeled
adverse reactions, there is going to be
under-reporting of adverse events and
also because
the drug has been on the market for a
long time, we
are not going to get a maximum number of
reports of
adverse events.
The quality of the reports
varied, as you
might expect. There are several data points that
seem to be more inconsistent and some of
those
144
included status of recovery. Some cases may not
have reported whether the patient
recovered or not,
and also time to that recovery.
(Slide 10)
This slide shows the number of
reports we
retrieved for each of the adverse events
we
searched for. There were 37 cases of NMS, 203
cases of acute dystonia, 57 cases of
akathisia, 35
cases of Parkinson's and 68 of tardive
dyskinesia.
(Slide 11)
Using those reports, we
developed our case
series which I will present to you. The case
series is going to include demographics
of the
patients and clinical characteristics
including any
information we have on recovery. I am also going
to spend some time talking about cases
that
reported continuing symptoms at the time
of
reporting. I will present some representative
cases and then focus a little bit on
cases
associated with short-term
metoclopramide therapy.
(Slide 12)
The first adverse event that
will be
145
presented is neuroleptic malignant
syndrome. We
had 37 unique cases. The age represented was a
mean of 49. The range of daily dose ranged from
7.5 to 80 milligrams with a mean of 33,
mostly I.V.
dosing represented here and mostly
G.I.-related
indications which will be very common in
the next
few slides. The range of duration of therapy was
from 1 to 196 days with a median of
three days.
(Slide 13)
In these 37 cases, concomitant
medications
that were associated with the
development of NMS or
NMS-like symptoms was reported in 20 and
they
included anti-depressants, anti-emetics
and
anti-psychotics.
One thing to remember is that not all
cases reported whether there were
concomitant
medications or not, so I have just
provided
information on the cases that have.
Drug therapy was used to treat
the adverse
event in 18 cases and it largely
consisted of what
would be considered standard of care for
neuroleptic malignant syndrome. The symptoms were
146
reported or resolved in 11 of the
cases. The
symptom was reported as continuing in
one of the
NMS cases but the symptom that was
reported as
continuing was more of a dystonic jaw
clenching.
In this series, eight patients died.
(Slide 14)
To look a little bit closer to
the
patients that died, in those eight
patients, the
daily dose of metoclopramide ranged from
10 to 40
milligrams with a mean of 32, kind of a
mix of oral
and I.V. dosing used, and the duration of
therapy
was short and ranged from two days to 15
days.
(Slide 15)
The first movement disorder,
in our view,
is acute dystonia. There were 203 unique cases.
Acute dystonia was reported in a younger
population
with a mean age of 32. The range of daily dose was
0.6 to 800 milligrams with a mean of 71
milligrams.
Largely oral dosing reported here. The range of
therapy from one dose to over 2000 days
but a short
median duration of therapy of two days.
Again, you see mostly G.I.
symptoms being
147
treated here although there were a
sizeable number
who were getting pre-treatment for
chemotherapy
with metoclopramide.
(Slide 16)
For these 203 acute dystonia
cases, there
were 64 cases which reported concomitant
medications that were associated with
movement
disorders, mostly anti-depressants and
anti-emetics. Drug therapy was used to treat the
adverse event in 115 cases. For these acute
dystonia cases, 115 cases reported the
symptoms as
improved or resolved. But symptoms were reported
as continuing in 12 cases.
(Slide 17)
In those 12 cases which
reported
continuing symptoms, the daily dose
ranged from 10
to 40 milligrams with a mean of 25,
mostly oral
dosing, and duration of therapy ranged
from one day
to over 2000 days with a median of 2.5
days.
(Slide 18)
We have 57 unique cases of
akathisia. The
mean age seen in this case series was
45. The
148
daily dose ranged from 5 to 200
milligrams with a
mean of 42, mostly oral dosing
again. Duration of
therapy ranged from one over 2500 days
with a
median duration of 17 days. Again, mostly G.I.
indications.
(Slide 19)
For these 57 cases akathisia,
concomitant
medications associated with movement
disorders was
reported in 23. Drug therapy was used to treat
akathisia in 29 cases. Symptoms were reported as
improved or resolved in 31 cases but
symptoms were
reported as continuing in nine cases.
(Slide 20)
In the nine cases that
reported continuing
symptoms, the daily dose ranged from 8.6
to 40
milligrams with a mean of 25 milligrams,
mostly
oral dosing. Duration of therapy ranged from 17 to
over 2500 days with a median duration of
119 days.
(Slide 21)
We reviewed 35 unique cases of
Parkinson's. This was in an older population with
a mean age of 60. Daily dose ranged from 10 to 80
149
milligrams with a mean dose of 36
milligrams per
day, mostly oral dosing. The duration of therapy
ranged from one to over 1400 days with a
median of
60 days.
(Slide 22)
In these 35 cases of Parkinson's,
there
were 13 cases which reported concomitant
medications that were associated with
movement
disorders. Drug therapy was used to treat the
adverse event in 18 cases.
Symptoms were reported as improved or
resolved in 15 of the cases but symptoms
were
reported as continuing in eight cases.
(Slide 23)
In those eight cases that
reported
continuing symptoms of Parkinson's, the
daily dose
ranged from 20 to 40 milligrams with a
mean of 32,
mostly oral dosing, and the duration of
therapy
ranged from one day to 203 days with a
median
duration of 81.
(Slide 24)
There were 67 cases of tardive
dyskinesia.
150
The mean age was 57. The daily dose ranged from 5
to 80 milligrams with a mean of 35,
mostly oral
dosing again. Duration of therapy ranged from one
to over 4700 days with a median of 180
days, again
G.I. indications for the metoclopramide.
(Slide 25)
25 cases reported that the
patient was
taking concomitant medications
associated with
movement disorders and drug therapy was
used to
treat the adverse event in 19
cases. In 12 of
these cases, symptoms were reported as
improved or
resolved. In 20 cases, symptoms were reported as
continuing.
(Slide 26)
In those 20 cases with
continuing
symptoms, the daily dose ranged from 5
to 80
milligrams with a mean of 53, mostly
oral dosing
and a duration of therapy from one to
over 4700
days with a median of 165 days.
(Slide 27)
After we developed our case
series, we
wanted to look at a more focused group
of these
151
cases to see if we could approximate the
dosing
seen in the MT100. So we looked at two further
subgroups of our case series. One, we looked at
characteristics of cases that
specifically reported
symptoms as continuing at the time of
reporting.
Then we also looked at cases with the
diagnosis of
tardive dyskinesia that were related to
short-term
metoclopramide therapy.
(Slide 28)
There were 50 cases out of
400, over 400,
that reported continuing symptoms. They were
represented by eight Parkinson's, 20
tardives, nine
akathisias, 12 acute dystonias and one
NMS which
was actually likely a dystonic
reaction. A little
over half of the cases with continuing
symptoms
reported a duration of therapy of
greater than 30
days.
(Slide 29)
So 15 cases in our series
reported
continuing symptoms with a duration of
therapy of
less than 31 days. Eight of those cases reported
continuing symptoms with a duration of
therapy of
152
less than three days, what we would call
very short
durations of therapy. That included one
Parkinsonism case, two tardive cases,
four acute
dystonias and one NMS. Most of those eight cases
occurred after at least three doses of
metoclopramide.
(Slide 30)
I have a few representative
cases to
describe to you. The first one is a 49-year-old
female who received two doses of
metoclopramide, 20
milligrams orally, over two days for
treatment of
gastric reflux. Concomitant therapy included
cimetidine. On Day 2 of therapy, she developed
dystonic reactions consisting of
torticollis and
trismus.
Her dystonic reaction was reversed by
diphenhydramine. However, she subsequently
complained of left-sided weakness and
temporary
loosing of the teeth.
(Slide 31)
The second case is a
34-year-old female
with nausea who received metoclopramide,
10
milligrams, orally three times a day for
three
153
doses and experienced difficulty
breathing,
extremity shaking, head and neck jerking
back. She
went to the E.D. where she was treated
with
benztropine, after which she started to
relax.
However, symptoms still
occurred. She was
subsequently treated with lorazepam and
paroxetine
which did not completely relieve the
symptoms. She
was seen in the E.C. and by neurologists
several
times for reactions milder than the
first reaction.
Approximately three months later, she
still suffers
from head pain, dizziness, tingling,
pressure,
fatigue, agitation, involuntary shaking,
muscle
spasm and neck pain among other
symptoms.
(Slide 32)
The third case, a 27-year-old
male
received three doses of metoclopramide,
10
milligrams orally, over two days for
diabetic
gastroparesis. He experienced a dystonic reaction
with psychotic tendencies, agitation and
agitation
with suicidal tendencies on the second
day of
therapy.
He was treated in the E.D.
with
154
diphenhydramine and lorazepam. Once discharged, he
continued to have symptoms of inability
to
concentrate, slowed mental processing,
difficulty
focusing, eye strain, vertigo, loss of
equilibrium,
fatigue, dizziness and hallucinations.
(Slide 33)
The second subgroup analysis
of our case
series that we did looked at specific
cases with
the diagnosis of tardive dyskinesia that
were
associated with short-term therapy of
metoclopramide of less than 30
days. What we were
trying to look at here was trying to
approximate
what kind of dosing regimen would be
seen with
chronic overusers of migraine therapy
because there
is a certain population of migrainers
who might use
this drug prophylactically in a manner
similar to
other migraine therapies.
We chose tardive dyskinesia as
our adverse
event because the diagnosis of tardive
dyskinesia
infers a long-term or permanent adverse
event. We
also noted that about 25 percent of our
cases had a
duration of therapy of less than 30
days.
155
(Slide 35)
You have seen this slide
before, but you
can see that this is the distribution of
our cases
based on the duration of therapy of
metoclopramide.
The large number are reported with
durations of
therapy of less than 90 days, but there
is a
significant number with durations of
therapy of
less than 30. Actually, there are 15 such cases of
tardive dyskinesia with a duration of
therapy of
less than 31 days.
Of these 15 cases, the status
of recovery
was not reported in nine of them. Symptoms were
reported as resolved in one case but
continuing
symptoms were reported in five of these
cases.
Some of the characteristics of these
cases include
two out of the five cases reported
symptoms as
continuing but improved. Two out of the five cases
reported I.V. dosing and four out of
five cases
reported daily doses of 40 milligrams.
The important thing to
remember is, again,
we are not really able to discern,
because of the
AERS data, whether this was chronic
intermittent
156
use of metoclopramide or chronic
continuous use of
metoclopramide in these cases.
(Slide 36)
In fact, we found no cases in
AERS that
specifically linked intermittent use of
metoclopramide with any movement
disorders. There
are maybe several reasons for this. First, and
probably most likely, is that AERS--the
way data is
reported in AERS does not make the
distinction
about intermittent dosing so it just
wasn't clearly
described in the report.
It could be that intermittent
dosing is
not commonly used or the adverse events
seen with
intermittent dose are not commonly
reported or that
there may be few
movement-disorder-related adverse
events with intermittent dosing.
(Slide 37)
So, in conclusion, most of the
reports
that we saw with continuing symptoms of
the adverse
event involved long-term therapy of
greater than 30
days with the caveat, again, that we
didn't know
whether it was intermittent or
continuous therapy.
157
There were eight cases which
reported
continuing symptoms with very short-term
therapy.
There were five cases of tardive
dyskinesia that
were associated with therapy of less
than 30 days.
Concomitant medications associated with
movement
disorders were frequently present in the
cases and
there were two out of eight deaths from
neuroleptic
malignancy syndrome that occurred after
less than
three days of therapy.
(Slide 38)
That's it.
DR. KIEBURTZ: Thank you.
Questions or clarifications
for our last
speaker?
DR. KIEBURTZ: Dr. Jeste.
DR. JESTE: In these cases of acute
dystonia and neuroleptic malignant
syndrome, some
of the patients have some concomitant
therapy as
shown, in these cases, the side effects
occur after
metoclopramide therapy.
DR. MATCHAR: Right; they were temporarily
associated with metoclopramide. Yes.
158
DR. KIEBURTZ: Dr. Porter.
DR. PORTER: Metoclopramide is not widely
used in the U.S. You didn't spend a lot of time on
the primary diagnosis. I presume that you found no
migraine-related movement disorders in
this search.
DR. MATCHAR: There were very, very few
cases that reported adverse events
related to
migraine. As you saw from the indications, they
were mostly G.I.-related indications.
DR. KIEBURTZ: Dr. Welch.
DR. WELCH: Were there any different
characteristics of the patients who had
the T.D.
after the short-term as opposed to the
long-term?
It is almost like a biphasic population
response
there.
DR. MATCHAR: No; it was a very
heterogeneous population. There were different
presentations, different durations of
therapy, so I
am not really sure whether you could say
those that
experienced it earlier had similar
characteristics
than those that presented after 90 days
of therapy.
DR. KIEBURTZ: Dr. Katz.
159
DR. KATZ: Just one point of clarification
which I think is true. Maybe you said it and I
missed it, but, obviously, we focused on
the
patients with continuing symptoms, at
least in
part.
As a general matter, I think, for these
reports, and correct me if I am wrong,
what we
don't have which would be nice to have
in terms of
information about those cases is sort of
the
latency between the onset of the event, the
movement disorder, and the time of the
report.
So it could be that an event
happened on
Day 1 and the report is made on Day 2,
in which
case, it might be continuing. But if the report
had been made on Day 47, after the drug
had been
discontinued, for example, it might be
that they
were discontinued. So I think, as a general
matter, we don't know this duration of
continuation
of symptoms because we don't know the
link between
when the event happened or stopped and
the time of
the reporting.
There were a few cases, I
think, where we
do have that but I think, in many cases,
we don't.
160
DR. MATCHAR: Right.
DR. KIEBURTZ: Dr. Hughes.
DR. HUGHES: You mentioned under-reporting
in the AERS database, a well-known problem. But
when you have an adverse event which is
labeled,
what sort of characterizes the types of
adverse
events that might then be reported? We are looking
at a very peculiar set here.
DR. MATCHAR: Probably.
There were a lot
of reports from lawyers. I mean, that is one.
Looking at other case series that I have
done, it
seemed like there were a lot of reports
from
lawyers.
But we looked at, actually, quarters of
years, the reports, and there really
didn't seem to
be any change, like an increase in
reporting after
cisipride came off. It seemed to be fairly steady
so I am not sure that I could say that
there was
one specific thing.
DR. KIEBURTZ: Good.
Thank you.
Questions from the Committee to the
Sponsor and FDA
Now, we have time to ask
questions of the
presenters without me suppressing you
about them to
161
be about clarifications. We have about an hour to
do that.
I suggest we start principally with
questions to the sponsor and immediately
with those
individuals who I suppressed.
I recall stopping Dr.
Goldstein when you
were asking Dr. Schapira a question
about the U.K.
reporting database, I believe, and Dr.
Lenaerts, I
stopped you in the middle of a question,
too, but I
can't remember the context.
DR. LENAERTS: It was in the same context.
DR. KIEBURTZ: Dr. Goldstein, would
you--and you can draw anyone from the
sponsor or
from the FDA if you would like to them
to repeat or
present material again.
DR. GOLDSTEIN: I guess what I was
actually asking for was clarification
about the
validity and accuracy and reporting
rates in the
U.K. system, especially now as
contrasted to the
last presentation we had from data here in
the
United States which is a similar sort of
reporting
system, but the numbers seem to be quite
different.
DR. SCHAPIRA: Thank you.
The U.K.
162
reporting system to the Committee of the
Safety of
Medicines, the so-called yellow-card
system, is a
system by which physicians send in to
the CSM
documentation of an adverse event. So it is
physician-led. It is not spontaneous in terms of
including patients. But it is spontaneous in the
sense that physicians have to send in
the yellow
card.
Those that do send in yellow
cards often
get a response back from the CSM asking for
further
clarification if all the relevant
information is
not included in the original yellow form
that they
have submitted.
As for a proportion of
reporting to all
potential cases, of course, I can't
comment on
that.
I don't know the data. Obviously,
that is
not possible to obtain.
DR. GOLDSTEIN: The second part of that
question--it was sort of a
two-parter--was, in
terms of validating the conditions that
are being
reported, we have this clear problem
with
categorizing a lot of these movement
disorders.
163
There is this point of definition about
how much
exposure is enough exposure to be
categorized as a
given type of condition. Are these validated in
any way, or is it just based on
individual
reporting.
DR. SCHAPIRA: It is predominantly based
on physician reporting.
DR. KIEBURTZ: It sounds analogous to what
we heard from Dr. Southworth. Dr. Bastings.
DR. BASTINGS: I have a comment regarding
the U.K. reporting system. We have a fair idea of
the incidence of acute dystonic
reactions with
metoclopramide. In the Pozen study, it was 0.05
percent.
I find it surprising to see that only 26
cases were reported with migraine
product, if you
consider the exposure, to have so few
cases and it
suggests that there was a vast
under-reporting of
these adverse reactions.
Do you have any comment on
that?
DR. SCHAPIRA: This, remember, was the
number of reported cases with migraine
preparations
as opposed to those with all
metoclopramide
164
preparations. Do you have the slide number from
which that is taken?
DR. BASTINGS: Yes; it is Slide 31, CC-31.
DR. SCHAPIRA: Just looking at all
metoclopramide preparations, that is to
say the
non-migraine ones, there were 478 of
those. I
don't know how that compares to the U.S.
data.
DR. SOUTHWORTH: There were 203 unique
dystonia cases.
DR. SCHAPIRA: In the U.S. data.
DR. SOUTHWORTH: Over about the early
'80's to present.
DR. SCHAPIRA: So this is actually twice
the number here in the U.K.
DR. KIEBURTZ: Over a longer period.
DR. SCHAPIRA: Over a period of 64 to 45.
So this is 40 years and the U.S. data
was over 35
years, I think. Is that right?
DR. SOUTHWORTH: The earliest reports we
have are from the early '80's.
DR. SCHAPIRA: So about 25 years.
DR. KATZ: I think the point is that we
165
have a good--an estimate, anyway, from
the Pozen
control trials of a particular adverse
event
associated with the acute use of the
product. It
is 0.05 percent or maybe it is 0.1
percent,
depending--we have seen those numbers
vary.
DR. SCHAPIRA: Yes.
DR. KATZ: But, when you look at, for
example, over the 40-year period in the
U.K., and
if you look at dystonia with episodic
use of the
combination products, which are the
migraine
products, there are 26 reports. So I don't know
what the percentage of use that is, but
it is
probably less than 0.1 percent.
I think that is the point from the
controlled trials, which are the best
way to get an
estimate of these events, you see some
finite risk.
It is relatively low but finite that the
reporting
rate seems to be, perhaps, orders of
magnitudes
less than that, the point being that
under-reporting may be a sizeable--there
may be
sizeable under-reporting for these
events which are
known to be associated with these
treatments.
166
DR. SCHAPIRA: Yes; I agree entirely. It
was just the comparison between the U.S.
and the
U.K. reporting system. It seems that there isn't a
difference between them here.
DR. KIEBURTZ: Dr. Hughes, did you have a
comment?
DR. HUGHES: A related question. I think
you mentioned there were no cases of
tardive
dyskinesia amongst the combination
users. I think
you mentioned something like 100 million
doses had
been prescribed. That was an estimate.
DR. SCHAPIRA: That was an estimate.
DR. HUGHES: But 24 cases amongst those on
chronic use.
DR. SCHAPIRA: Yes.
DR. HUGHES: Do you have an idea of how
many doses have been prescribed for
chronic use? I
am trying to get some sense of--
DR. SCHAPIRA: Right.
Of course, I am
going to have to speculate on this, but
the
proportion of use of metoclopramide in
the U.K. for
migraine as a precaution for all of its
other uses
167
is about 20 to 25 percent of
metoclopramide
prescriptions are for migraine,
approximately. So
I suppose that one could extrapolate
from that.
DR. KIEBURTZ: Dr. Temple.
DR. TEMPLE: Just a comment on reporting
rates and spontaneous reporting
systems. We spend
endless hours and months agonizing about
this. It
is very clear the rates are different
for different
kinds of reactions. There is something called the
Weber curve that was derived mostly from
British
data that says reports of any given
reaction
decline after the first three years
because people
all know about it. It is in the label.
You can easily imagine that
people
wouldn't report very much of something
like a
dystonic reaction which everybody knows
about. You
would hope that they would be more
likely to report
TD because it is not as clear that
everybody knows
about it. But there is just no way to know these
things and it is a constant source of
difficulty.
The other thing that is going
on, in the
United States, in the '80s, there were
maybe 20,000
168
reports to us a year. You probably have the
number.
We are now up over 400,000 a year.
So we
have a belief that reporting of all
things is going
up.
It is very impossible to reach conclusions
that are valid, however.
DR. KIEBURTZ: Dr. Jung.
DR. JUNG: I will pass.
DR. KIEBURTZ: Dr. Fahn.
DR. FAHN: Regarding Slide 31 and then 22,
where there is no tardive dyskinesia
being
reported, Slide 22, the Bateman second
article
there, the Bateman 1989, the second of
the Bateman
articles, fortunately, and I must
congratulate the
sponsor because we do have the reprints
of these
articles so I was looking at that
because that came
as a big surprise where there were zero
TD cases.
But, actually, what this
survey was is
that they wrote to the physicians who
prescribed
the drug Maxolon for migraine--I assume it
is all
for migraine--and got the responses
back. But they
grouped the responses. They didn't list tardive
dyskinesia as one of the responses. They just said
169
dystonia-dyskinesias and they grouped
all that
together. So they are listed here in your table as
12 dystonias. But a lot of them--and some of these
are older people. It is very likely that a lot of
these were persistent dyskinesias and
not just
acute dystonic reactions or something
that this
table may imply.
So I just wanted to say that,
looking at
this, you can't really clearly say how
many--there
was no zero TD cases. So that was one comment.
DR. SCHAPIRA: Yes; they classified
patients as dystonia-dyskinesia which,
if you look
back at the first Bateman paper here,
they also
used that classification and separated
out from
tardive dyskinesia. So, in the first paper they
did, they did clearly separate
dystonia-dyskinesia
and tardive dyskinesia. In the dystonia-dyskinesia
they noted that--I think the dyskinesia
resolved
and made the comment--and this is with
respect to
their paper in 1985--that this was more
likely an
acute type reaction.
DR. FAHN: But the other thing on this
170
table, too, in the second Bateman article,
they
have 46 other events. So, perhaps, within that,
there might be TD. That is what I am saying. From
this paper, you can't really say there
was no TD
because they specifically failed to talk
about TD.
That is the problem.
If I can also make a comment
at this time.
The definitions of TD, that is another
thing that
can confuse people. If you are going to use the
definition of TD that you have to be on
the drug
for 30 days or more or three months, as
some
definitions have used, I am not sure any
neurologist used that kind of
definition. We
tended to look at tardive dyskinesia as
persistent
dyskinesia.
The name tardive was given
because it
wasn't seen until later on after the
neuroleptic
drugs had been on the market for a
while. That is
when tardive came on. But, with more experience
with this, recognizing what the
syndromes are, we
sort of consider, now, tardive
dyskinesia really
should have been properly named
persistent
171
dyskinesia, meaning that it lasts longer
than 30
days.
It doesn't matter how long
they have been
on it for. They can be on it for one day and still
have persistent dyskinesia. To us, that is what we
now refer to as tardive dyskinesia. So we don't
give up the name tardive
dyskinesia. We use the
definition differently than what was
stated here.
I just wanted to make sure the concern I
would
have, as a neurologist, who treats
tardive
dyskinesia as meaning persistent
dyskinesia, that
these can be irreversible.
When I heard the comment about
how
devastating migraine is, and I agree it
can
be--severe pains can be very bad for
people,
devastating, but so can severe akathisia
including
tardive akathisia, I consider that
equally as bad.
If you ever induce this for a drug you
might not
have needed, then that is a concern for
us that we
have to face.
DR. KIEBURTZ: I am going to follow your
comment and pursue questions with a
couple of
172
people.
Neurologists fall into camps of movement
disorders and stroke and headache. I think, just
to set tone, I think everyone would
agree that
migraine is a serious and disabling
disorder that
needs good treatments. I don't think anyone is
debating that. And there are unmet therapeutic
needs.
I think everyone also admits,
but might
not be so familiar with, that tardive
syndromes,
tardive dyskinesia and other tardive
syndromes, are
also very disabling, much less common
than
migraine. The issue before us is how to balance
those issues. Neither is more important or less
important than the other. They are both very
important clinical issues. I don't think anyone is
doubting that. So I don't want to have that sort
of be on the table, that we are
undervaluing one or
the other.
Dr. Lenaerts.
DR. LENAERTS: Thank you.
In the U.K.
experience, could Dr. Schapira
possibly--I don't
know if it is hypothetical or known
173
information--the comment on the use of
metoclopramide specifically in
migrainers and,
namely, the frequency of use as that may
factor in
the relatively low reports of adverse events
in
migrainers as compared to the U.S.
experience.
DR. SCHAPIRA: Thank you.
Well, as I
mentioned, the combination of
metoclopramide and
analgesics is the second step in the
U.K.-recommended guidelines for the
management of
acute migraine. The estimate of prescriptions of
combinations, of the two combinations
currently
marketed, is approximately 200,000 per
annum. It
is estimated that about 95,000 patients
are taking
these products each year.
DR. LENAERTS: How does that do--in terms
of frequency of use per patient because
that would
be really the relevant issue there.
DR. SCHAPIRA: Of course, that is
undoubtedly going to vary from one
patient to
another depending upon the severity of
response,
frequency of attacks, et cetera. The sort of
bottom-line figure, if you like, that we
have is 85
174
doses per annum. But, between that, there is going
to be a substantial range.
For instance, one has patients
who will
take two doses at the onset of an attack
and have a
good effect from that. Another proportion of
patients will need to take two doses
separated by
four hours.
But what I don't have is the
data to tell
you what proportion take just one dose
at the
beginning, two doses, et cetera. I don't have the
data and don't think it is available to
tell me how
many migraine attacks they are treating
per year.
I can only give you that bottom line of
about 85
per person per annum.
DR. KIEBURTZ: Dr. Welch?
DR. WELCH: Do you have any comment on any
difference in prevalence of medication
overuse
between Britain and the United States?
DR. SCHAPIRA: I think I should pass that
to one of my U.S. migraine experts
because I think
they will probably know more about that
in terms of
the prevalence of medication overuse.
175
DR. KIEBURTZ: If you haven't spoken
before, just please introduce yourself
for the
record.
DR. SAPER: My name is Joel Saper. I am a
neurologist specializing in headache and
Director
of the Michigan Head Pain and
Neurological
Institute in Ann Arbor. Dr. Welch, could you--I
got part of that question. I didn't hear the whole
question.
DR. WELCH: What is the prevalence of
medication overuse in the U.K. and what
is the
prevalence of medication overuse in the
United
States?
DR. SAPER: I am not sure that I can
answer the question with specific
statistics. I
think Dr. Silberstein showed a slide,
was it 1 to 2
percent, Steve, on the medication
overuse in the
United States?
DR. SILBERSTEIN: The data is
extraordinarily limited. The two studies I know
of, population-based studies, in
medication overuse
headache, Ann Scher's study done in this
region.
176
What Ann and Richard Lipton showed is
about 4
percent of the population have chronic
daily
headache. In the clinic, it is estimated that most
of the patients we see with daily
headache overuse
medication, what Ann and Richard
estimated in the
population is about 30 percent.
I don't know of any good
estimates in
Great Britain. I do know that, in other parts of
the world where the problem has been
studied, all
worldwide estimates of chronic daily
headache are
about 4 percent and half are migraine,
and of those
patients, about 30 to 40 percent in
population-based studies.
Anecdotal experience from
Peter Goadsby in
National Hospital in Queens Square
suggests that is
clinic-based population is about the
same as here.
Mike, do you know of any population-based
estimates? Anyone?
DR. SCHAPIRA: No.
So, in other words, we
don't know whether the medication
overuse is less
in the United Kingdom than here and we
are being
given data on the adverse events in
Britain.
177
DR. SAPER: If I may just finish the point
I wished to make when I asked Dr.
Silberstein for a
clarification, I do know this. In our system, in
the United States, medication overuse is
a
significant problem of the referral base
that is
referred to us, perhaps 60 to 70 percent
of
referrals to a tertiary quadrinary will
have that
problem.
In the U.K., I do not know for
other than
opioids.
In opioids, which is the dominant overuse
in this country, in my referral base,
which is very
large.
In the U.K., opioid use is much more
limited.
So, to the extent that we can compare
opioid overuse in the United States to
that in the
U.K., there would be much more overuse
in the
United States, but specifically
targeting the
opioids.
DR. WELCH: Do you think that speaks to
the difference in physician practice in
the United
Kingdom--in other words, major
primary-care control
of the prescriptions in the United
Kingdom as
opposed to the United States?
178
DR. SAPER: There is, I think, a
difference in prescribing habits, Dr.
Welch. I
think, in the United States, opioids,
particularly
in the last ten years, are being much
more
aggressively prescribed for non-cancer
pain than
they were prescribed ten or fifteen
years ago.
In the U.K., from my
understanding and
talking to colleagues, the opioids are
restricted
much more so for non-cancer pain.
DR. KIEBURTZ: Dr. Hughes, you had a
question.
DR. HUGHES: Sort of two related
questions. Going back to the Reglan warning label
and the comment in that label about risk
of TD
being increased after relatively brief
treatment
periods at low doses, is there data
available that
is underpinning that particular comment?
DR. BASTINGS: We don't know what that was
based on. We did not write that label. It is a
different division and we don't have
that
information.
DR. KIEBURTZ: I am not sure it is
179
data-driven but, even in the comments you
saw in
the Pozen briefing booklet, I believe,
amongst
movement-disorder neurologists, there is
the
impression that even one dose of
exposure can
possibly cause tardive syndromes.
To answer your question, I am
not familiar
with data to address the question but
the label may
have incorporated clinical acumen or
anecdote as
part of the label.
DR. HUGHES: I guess the related question
was the open-label safety study that you
have
conducted, I was wondering if there were
eligibility restrictions or the
treatment-management approach within
that study was
conservative to try and avoid risk of
movement
disorders.
DR. ALEXANDER: Thank you.
This study we
call 302 enrolled 1,006 subjects. They were
enrolled on the basis of having a
history of
migraine. But there were no restrictions on
previous presence of movement disorders or
any
persistent neurologist deficits. We had not, at
180
the time of that study being initiated,
anticipated
that this would be an issue in the
development and
so there were no particular
requirements.
DR. HUGHES: And there weren't any
particular requirements in terms of
management of
patients?
DR. ALEXANDER: Well, no.
This was 54
centers, I believe, headache centers in
the U.S.,
generally, and patients were instructed
to take one
dose of MT100--this was open label--one
dose for
the treatment of moderate to severe
headache.
There was no second use of MT100 as
rescue
medication, for example.
It was a safety study. Subjects were
asked to record adverse events after
taking doses
within 24 hours and then, when they came
back to
clinic, at 3-month intervals.
DR. HUGHES: But these patients were
taking it on a chronic intermittent
basis.
DR. ALEXANDER: Well, I would call it--I
would like to make the distinction that
we are
talking about episodic or PRN use because
chronic
181
intermittent could also include the
psychiatric use
of neuroleptics in the treatment of
schizophrenia,
for example.
One thing I would point out is
that the
episodic three-times-a-month use is
probably very
different than chronic intermittent
time-on/time-off of a neuroleptic used
in the
treatment of psychiatric conditions. These were
PRN intermittent. As Dr. Schapira has shown, the
average number of doses per month was 4
and the
median number of doses that each subject
took over
the 12-month period was 22.
DR. HUGHES: So would you characterize the
study as mimicking what might occur in
clinical
practice?
DR. ALEXANDER: Yes; exactly.
It was a
clinical-practice type study, a
real-world study,
just looking at the adverse-event
collection over
the time enrolled.
DR. KIEBURTZ: Dr. Katz, you had a
question?
DR. KATZ: No; he answered my question.
182
DR. KIEBURTZ: Dr. Jeste.
DR. JESTE: Do you have a theory why
metoclopramide would work better in
people without
nausea?
DR. ALEXANDER: Thank you, Dr. Jeste. We
believe, and we have phase 1 data to
show, that the
addition of metoclopramide to naproxen
sodium will
enhance the absorption of naproxen
through
accelerating the--well, it brings the
T-max closer
to the time of dose. We have phase 1 studies
showing that the T-max for naproxen is
decreased by
about 30 minutes, on average.
That is Slide 25.
(Slide EB--25)
Just to illustrate this point
further, is
that, in the phase 1 studies, when we
gave naproxen
sodium 500 milligrams without
metoclopramide, the
T-max was 72 minutes. We added, first, 8
milligrams of metoclopramide and the
T-max dropped
to 57.
With 16 milligrams, which is the dose in
MT100, the T-max was 44. So I think I am answering
your question about why it speeds the
absorption
183
because it empties the stomach. Naproxen is only
absorbed in small bowel as are all the
other
NSAIDs.
DR. JESTE: So you think it would work
differently in people without versus
with nausea?
DR. ALEXANDER: I have no data for sure.
The theory, just to answer that, is that
when
nausea is present, there is probably
more gastric
stasis, and 16 milligrams of
metoclopramide cannot
overcome the gastric stasis present.
There also may be--there is a
theory that
dopamine has effects in migraine and maybe
the
dopamine has an effect to increase
nausea.
DR. KIEBURTZ: Dr. Sacco is next.
DR. SACCO: I had a question regarding
adverse experiences for someone from the
company to
maybe comment. Looking at the FDA briefing
document, in the clinical review
section, FDA
Clinical Review, there is an overview
that puts
together all the adverse
experiences. I would like
someone to just comment for me, as a
stroke
neurologist, not a movement-disorder
neurologist,
184
how best to be sure that the increased
frequencies
of restlessness and feeling jittery that
are noted
with MT100 and MT100 two tablets versus
some of the
other groups wouldn't be possibly forme
fruste or
partial TD-related symptoms.
This is on Page 103 of 128 in
the FDA
document.
DR. KIEBURTZ: Your document may not be
entirely the same as theirs. But I am not sure. I
believe they would know the table.
DR. KATZ: Could you just repeat which
page, which document.
DR. SACCO: The document I have, which is
under a section called FDA Clinical
Review, it is
Page 103 of 128 in the section, I guess,
document
dated--Table 64. I have a table number. I guess
my question just is, again, getting back
to that
original slide where I asked the
clarification,
akathisia, restlessness, is possibly a
form of
tardive dyskinesia. Being, again, a stroke
neurologist, I am just trying to
understand and be
sure that the restlessness and feeling
jittery
185
issues that are listed in that table
that are
increased--I see 13 in the MT100 group
and then,
actually, 12 or 4 percent in the MT100
two tablets
group, and I see feeling jittery, 13 and
4, also
there.
I am just trying to get a
better handle,
maybe, from the company what some of
those adverse
experiences were all about.
DR. ALEXANDER: Thank you, Dr.
Sacco. I
am looking at Table 64, that the data
across all
the treatment--each treatment arm. I would point
out that, if you look at restlessness
with MT100,
there were 2400 subjects who were
exposed to a
single dose. There were 13 cases of restlessness
there, less than 1 percent.
That was the same percentage
relative to
the restlessness in naproxen sodium,
metoclopramide, sumatriptan and
placebo. All were
less than 1 percent. You have pointed out that
there is a 4 percent incidence of
restlessness with
the two-tablet dose of MT100. There were 313
subjects who received the two-tablet
dose.
186
Pozen has not, did not, submit
the NDA
asking for approval of a two-tablet dose
of MT100.
So, therefore, the 4 percent higher rate
of
restlessness may not be relevant to our
discussions
today.
But I would want to say that
these were
acute events that were seen and they did
resolve.
The question of restlessness with the
use of MT100
could, perhaps, be looked at in the 302
database
just to put this in perspective.
Let me have, please, Slide No.
19.
(Slide SA-19)
This is the study, the large
study,
repeat-dose study, that we have spoken about. I
just think it might be beneficial to the
committee
to see that the most common event in
these 1,006
subjects was somnolence, dizziness, 7
percent.
Restlessness, overall, was 2
percent. Again, these
are 23,000 single doses of MT100 being
treated,
being used by these 1,006 patients.
Anxiety is 4 percent and
nervousness, 1
percent.
Fatigue is a little more common.
187
Perhaps, that would help put this in
context.
DR. KIEBURTZ: Thanks.
Actually, Dr.
Temple and Katz, but we are keeping a
list.
DR. TEMPLE: I am still curious about the
theory of why the people with no nausea
might
benefit.
You might even think that, if they have
delayed absorption, they would benefit
more--you
might.
I guess I couldn't understand what the
theoretical basis for expecting a
benefit on the
sustained response and not on the acute
response
would be. If you shortened T-max, it would seem
more likely to do the opposite, I would
have
thought.
That is a question to the
people who put
forth the theory, not to the committee.
DR. ALEXANDER: I'm sorry.
I thought you
were posing that to committee. I think the
question would be what happens when
migraine is
effectively treated by an analgesic
agent. We
don't know the effective plasma dose of
naproxen
that will start the process of
analgesia. I don't
think we know that.
188
So we, in theory, if we can
bring the time
of obtaining whatever that is closer to
dosing and
start the process of analgesia and the
effect on
neurovascular leakage or whatever it is
that is
causing the migraine pain, then we can
effect,
perhaps, a smaller two-hour
improvement. But that
improvement then goes on after two hours
to 24, and
we see less relapse. We see less need for
remedication and the pain response, as
measured by
sustained pain response, may be there.
That is just a theory. But, certainly,
the quicker you treat the pain, perhaps
the better
it will be at 24 hours.
DR. TEMPLE: Plausible.
But it doesn't
treat it quicker. I mean, that is what the results
show.
DR. ALEXANDER: Remember I showed the SPID
data.
SPID data is used in the analgesic division
as the most sensitive tool we have to
measure the
duration, the onset, the amount of pain
relief.
And we showed, in both studies, that, by
two hours,
MT100 was statistically significantly
better than
189
naproxen sodium using SPID scores.
So I would just say we have data that
makes it effective. Let's have Slide 83.
(Slide EB-83)
Just to answer this. The SPID scores in
Study 301. The pink line at the top is MT100. The
blue line is naproxen sodium. The green line is
metoclopramide. At one hour, MT100 is
significantly better than
metoclopramide. At
one-and-a-half hours, naproxen sodium is
better
than metoclopramide. At two hours, MT100 is
significantly better than naproxen
sodium, p-value
0.044.
The same thing was seen in
304. The next
slide would be, I think, 84.
(Slide EB-84)
Importantly, in 304, this
effect was seen
and one-and-a-half hours. By, by one-and-a-half
hours after dosing, you have separation
of these
two treatments.
DR. KIEBURTZ: Dr. Welch.
DR. WELCH: I would like to pursue the
190
same issues that Dr. Temple is
discussing. There
may be other explanations other than
just simply
absorption from the gut. When you look at the PET
studies or MR studies, you find that
basal ganglia
and a whole network of systems are
activated during
an acute migraine attack. It could be that it is
interfering with that at some stage or
other.
But I would really like you to
address the
issue of the time from the onset of the
migraine
attack to treatment as another possible
explanation. Nausea is very variable. Sometimes
it comes on in the middle of the attack
and often
is associated with the severity of the
pain or
severity of the attack.
Could it be, can you reassure
us, in
making this differentiation of a 10
percent
difference between nausea and non-nausea
and you
don't have a population that treated
itself at a
different time, and if, for example, the
group
without nausea treated themselves
earlier than the
group with nausea, then you might expect
a
differential benefit because you are
interfering
191
earlier with the cascade of events
involved in the
migraine attack. So there is another possible
explanation that may have nothing
whatsoever to do
with absorption from the gut.
DR. KIEBURTZ: Let me just, to clarify,
your
question is is there evidence regarding the
time that has passed between the onset
of headache
and the self taking of the medication in
those who
report nausea versus those who don't as
a possible
potential explanation.
DR. WELCH: Correct.
DR. KIEBURTZ: Could you address that
specifically? Do you have that?
DR. ALEXANDER: First of all, Dr. Welch, I
don't have data to answer your
question. We did
not measure the time from onset to
treatment in
these studies. I think you are referring to early
treatment modalities and perhaps
treating when the
pain is mild or moderate before nausea
may develop
in a subject. We just don't have data to support
that.
DR. WELCH: It is not necessarily mild.
192
It is the duration--it is the time when
you treat
it first.
DR. KIEBURTZ: Thank you.
Dr. Jung.
DR. JUNG: Can we go back to Table 19.
DR. ALEXANDER: That is the overall safety
data from 302?
DR. JUNG: Can you tell me what the
difference is between restlessness,
anxiety and
nervousness? Was there a specific way of
differentiating for the patients or for
the
providers who submitted the reports?
DR. ALEXANDER: No; there wasn't. These
were characterization of the
adverse-event reports
by the investigators who recorded the
data in the
case-report form.
DR. KIEBURTZ: Are those WHO-ART coded?
Are these verbatim? Does anybody know?
DR. ALEXANDER: They do get coded through
the WHO-ART system, or CoStart
system--I'm sorry;
the MedDRA system.
DR. KIEBURTZ: So these are MedDRA roll-up
terms?
193
DR. ALEXANDER: Yes.
DR. KIEBURTZ: So that means that these
are terms, the text was coded into these
terms. To
be sure, you would have--this is not the
actual
verbatim; correct?
DR. ALEXANDER: Well, it may be. I would
have to look--
DR. KIEBURTZ: It may or may not be.
DR. ALEXANDER: I would have to look at
the MedDRA Coding Guidelines to see if
these are
verbatim. But there are some terms that, as you
say, do get coded to something else.
DR. JUNG: Does that mean that there is
clarity between the difference between
anxiety,
nervousness--there isn't?
DR. ALEXANDER: No.
DR. JUNG: So if you take restlessness,
anxiety and nervousness and added all
that up in
terms of adverse events, wouldn't that
be pretty
close to the primary 108 that was
reported
somnolence? If you have restlessness, anxiety and
nervousness, that is 50, 60--
194
DR. ALEXANDER: It is a percent. If you
look at the bottom of that column, 78
percent of
these subjects who were treated for up
to a year,
at some time or another, reported some
adverse
event.
I don't think it is uncommon to have 78
percent of the subjects reporting
something over
the course of a 12-month study.
DR. JUNG: I had a second question.
DR. KIEBURTZ: Please, go ahead.
DR. JUNG: Not related to the slide.
Going back to Dr. Fahn's comments
earlier about the
significance of movement disorders on
quality of
life, do we have--this is for the FDA
staff--do we
have any data that looks at the incidence
of other
adverse effects associated with other
treatments
for migraines, so, for example,
cardiovascular side
effects, G.I. side effects, just for
comparison?
DR. KATZ: The rates of things like chest
discomfort and stuff can be read in the
labeling
for all these drugs. They are not inconsiderable.
There is a fair rate in those
things. But I don't
think we have them on the top of our
head at the
195
moment.
Anybody with a Blackberry can probably
find it.
DR. JUNG: I guess my point was that, if
we are trying to decide whether or not
this drug is
worthwhile, it would be reasonable to
compare that.
DR. KIEBURTZ: Dr. Porter?
DR. PORTER: Back to Dr. Schapira. On
your combinations on metoclopramide and
analgesics
marketed in the U.K. and the 95,000
patients per
year that receive these doses which are twice that
of the MT dose, the question arises
which is in a
similar vein to what other people have
asked. On
the dystonia oculogyric crisis, for
example, or
extrapyramidal disorders not specified,
what is the
possibility that a substantial number of
those, or
even some of those, could be tardive
dyskinesias
and not just properly classified. That would make
a big difference, I think, in our interpretation
of
this rather impressive database if we
thought that
that was possible.
DR. SCHAPIRA: The identification of
dystonia or oculogyric crisis is a
phenomenon
196
associated with the acute, generally
speaking,
exposure to a neuroleptic specifically,
in this
context, metoclopramide. Therefore, they are, I
believe, more easily distinguished in
terms of an
acute dystonic episode from tardive
dyskinesia.
Also, acute oculogyric crises
or acute
dystonia, upon exposure, which may, for
instance,
occur with the first dose ever of
metoclopramide,
resolves spontaneously and I think can
be more
easily, or relatively easily,
distinguished from
tardive dyskinesia which, generally
speaking,
involves a different type of movement.
Stan has already--I'm sorry;
Dr. Fahn has
already alluded to the issue of
persistent
dyskinesias as opposed to tardive
dyskinesias. I
would make a distinction between those
persistent,
brackets, tardive, brackets, dyskinesias
and the
sort of acute oculogyric, acute
dystonic, reactions
that we see with metoclopramide.
DR. PORTER: So you don't think that these
dystonia extrapyramidal disorders
dyskinesia were
persistent in the same way that tardive
dyskinesia
197
might be persistent.
DR. SCHAPIRA: Well, I can only speculate,
of course, because I don't have the
original case
reports in front of me. But, as these have come
from medical practitioners, I would hope
that at
least the great majority of them, the
vast majority
of them, would relate specifically to an
acute
dystonic reaction. Otherwise, they would have
been, I would hope, classified as
something else.
DR. PORTER: They had at least the option
to check a box that was tardive
dyskinesia?
DR. SCHAPIRA: They wouldn't, I believe,
have a box to check. They would have a space to
include what they thought.
DR. PORTER: Okay.
Thank you very much.
DR. KIEBURTZ: Can I have four more people
I have no my list. Those are Drs. Goldstein,
Jeste, Sacco and Katz and I have a
couple of
questions. So if we get through those, then we can
do more.
DR. GOLDSTEIN: First, just a few
questions for clarification just for me,
I guess.
198
The data that you showed very quickly
about the
difference in time in rate of onset, I
guess, for
the three treatments that were just
shown, the
statistics for that. I know there is this whole
debate about what is the right
statistics to use
but, in that particular graph, you were
showing
repeated measures over time. I was wanting to know
whether those were just uncorrected
pairwise
statistical comparisons or whether that
was
analysis of variance with repeated measures
and
then post hoc tests.
DR. ALEXANDER: Dr. Goldstein, are you
speaking of the SPID scores?
DR. GOLDSTEIN: Yes.
DR. ALEXANDER: Could we have the SPID
score methodology? Just come on over, Susan.
Susan Spruill is the Senior Director of
Biostatistics at Pozen.
DR. SPRUILL: The answer to your question
is that it was an analysis of variance
for each
time point and it was not corrected for
multiple
time points.
199
DR. GOLDSTEIN: So it wasn't corrected.
Okay.
The second question is, again, just a
general question about the trials that
were done.
You guys must have measured or recorded
concomitant
medications. Many patients with migraine are also
on prophylactic therapy as well as this
rescue
therapy.
This is basically a rescue therapy.
Were there differences in what
types of
other medications these patients were
on?
DR. ALEXANDER: There were exclusion
criteria if patients had changed their
prophylactic
medication within several weeks to a
month of
enrollment. We did not exclude patients that were
on prophylactic medications or
anti-depressants,
anything that was used for the routine
medical
treatment. There was no stratification of the
randomization by use of prophylactic
medications.
DR. GOLDSTEIN: Thanks.
The third
technical question is, again, related to
this whole
issue of absorption. The preparation that you are
looking at here has the naproxen that is
sort of
like buried inside this sort of
shell. Is there a
200
difference in the bioavailability of the
naproxen
alone in that preparation? You said you used that
in the controls also in the
studies. Is there a
difference in bioavailability of that
compared to
the usual preparation of naproxen if you
would get
it within that particular formulation?
DR. ALEXANDER: I am really not qualified
to answer that with data. My impression is that
there is no difference.
DR. PORTER: The point, I guess, is that
what you are hypothesizing is that the
metoclopramide is improving the
absorption of the
naproxen in this particular preparation
because
that is the comparison you have. But you don't
know that, if you didn't have it in this
particular
preparation, that there would or would
not be a
difference.
DR. ALEXANDER: No; we used the same
blinded study medication that was
naproxen in the
core with a placebo around it in these
studies that
were conducted. So I would answer to say that it
seems that we have controlled for
everything except
201
the metoclopramide component.
DR. KIEBURTZ: Let me just restate it. I
think your question is, in the naproxen
alone, how
does that compare to a standard naproxen
preparation.
DR. GOLDSTEIN: Exactly.
DR. KIEBURTZ: Does the formulation here
somehow delay the naproxen so that the
metoclopramide then just speeds it back
to normal?
DR. GOLDSTEIN: That is exactly right.
DR. ALEXANDER: Let me clarify. These two
are bioequivalent as far as the naproxen
component.
I was not familiar with the study.
DR. KIEBURTZ: Dr. Jeste.
DR. JESTE: If people with nausea respond
differently to metoclopramide, that
people without
nausea have greater therapeutic benefit,
it is also
possible that they may have differential
response
in terms of side effects. They might have more
side effects or less side effects than
people with
nausea.
Do you have any evidence for
that?
202
DR. ALEXANDER: That is one of the things
that we looked at very quickly after
seeing this
efficacy difference was to see if there
was any
apparent difference in adverse events.
There are
none.
Again, these were prespecified analysis for
the endpoint subgroups so we went back
and looked
at the adverse events. There is no difference
between the two subgroups as far as
adverse events.
DR. SACCO: It is a question for, I think,
Dr. Schapira maybe to comment on. We heard from
Dr. Matchar about this unmet need, about
the number
of people suffering with migraine, the
disability,
and how this drug could, perhaps, be an
unmet need.
One of your slides talks about
the fact
that this is available in the U.K. and
some of your
numbers have been 95,000 patients
possibly treated.
I
guess what I am trying to get an understanding of
is in the U.K., using the U.K. as an
example, the
sponsor provided in their document,
Appendix 3,
which talks about prescription use in
migraine
patients.
If anything, at least from my
203
interpretation of this table, the
migraine
anti-emetic combinations, of which the
main one is
this kind of drug out there, is dropping
kind of
precipitously from November, 1999, about
112,000 to
79,000 in November of 2003.
When you look at the overall
proportion of
migraine sufferers again estimated in
these tables,
it is a little lower and dropping, so,
just again,
a feel for, if we use the U.K. as an
experience
where this drug was available, we
recognize the
unmet needs that perhaps are possible in
the U.S.,
can you comment on why this seems to be
dropping
off as a migraine type of drug.
DR. SCHAPIRA: Yes. I
think that the
guidelines that have incorporated the
use of these
combinations into the acute treatment of
migraine
is in response to a need to rationalize
the acute
treatment of migraine.
First of all, I think many
patients with
migraine never even go to a doctor. They just
treat a headache, themselves. Those that do go to
a doctor, I think are recommended to
begin an
204
analgesic just to see if they have tried
that and,
if they have and have not responded,
then there is
a pressure, if you like, from the guidelines,
the
Headache Society in the U.K., et cetera,
to try and
build the patient's future management on
an
appropriate logical step which is, if
you like,
tailored to the patient because I think
a
significant proportion of patients are
being taken
from simple analgesic to triptan without
this step
in between.
I think, to some extent, this
is a
response to the introduction and
marketing of
triptans in the U.K. What we have tried to do is
to actually insert this intermediate
step between
those two.
DR. KIEBURTZ: Which one of you two--you
had your hand up before, or would you
like Dr.
Bastings--
DR. KATZ: Eric has, I think, an
interesting question but I just have a
few maybe
sort of random thoughts. The side-effect profile
or incidences that were shown for Study
302, that
205
is open-label data. It is hard, really, to
understand exactly what those numbers
mean. There
is no concurrent control group.
I don't know. I didn't really understand
Dr. Alexander's answer when he said,
well, you add
them all up, you get 78 percent of
people reported
some sort of an adverse event,
therefore, it is not
unexpected.
I think Dr. Jung's point is a
very good
one.
We are well familiar with the distinction
between lumpers and splitters when
adverse events
are recorded and reported. Of course, it is hard
to do know what to make of the specific
point here
about adding up all these things because
we have no
idea, really, what those terms
represent, which is
a point, I think, that has been made.
But, certainly, of course, it
is possible
that the restlessness, anxiety,
nervousness,
sleeplessness, whatever these things
are, it is
possible that they are all akathisia or
some
extrapyramidal symptom. It is hard to know, but I
think the point is a very good one that,
206
generically, these sorts of events are notoriously
poorly reported, not in this application
specifically, but across applications,
and poorly
translated from verbatim reports to
MedDRA or
CoStart.
So that is something to watch
out for. It
is true individually they are less than
what--but,
even if you look individually, they are
all less
than 1 percent more or less across all
the groups.
But, 0.9 percent is different, perhaps,
then 0.2
percent.
But if you just list them all as less
than 1 percent, they all look the same.
So that is just something to
keep in mind.
Again, it is hard to know what to make
of it
specifically in this case.
The only other thing I want to
say is
there has been a lot of discussion about
the
rationale of why it should be true that
it works in
people who don't have nausea at
baseline. Anything
is going to be somebody's interesting
theory. It
is impossible to really know what the
rationale
would be.
207
It would be nice to know what
the
rationale was to sort of have a real
solid
well-accepted rationale in hand because
I do think,
as Dr. Temple said, that this was
probably an
unexpected finding. It was probably expected to
work better in people who had nausea at
baseline.
There is going to be a retrospective
explanation,
but we are mostly concerned about
whether or not it
is a real effect and, as one of our
questions asks,
whether or not it is an appropriate,
well-defined
population.
So just sort of generically, I
think we
are probably less concerned with the
rationale for
it than is it real and is it a
population that we
can reliably identify so that we can
write
labeling.
DR. KIEBURTZ: Why isn't as important as
if.
Dr. Bastings.
DR. BASTINGS: It is a question to Dr.
Schapira regarding these combinations
available in
U.K.
Is there any evidence from controlled studies
208
that metoclopramide provides any
contribution to
efficacy for these preparations?
DR. SCHAPIRA: Thank you.
I have not
actually looked at and don't have access
to the
original data on Paramax or
MigraMax. But I think
that Dr. Alexander may have in order to
answer your
question.
DR. ALEXANDER: Your question is whether
or not there is data that this
combination would be
effective in migraine.
DR. BASTINGS: No.
DR. KIEBURTZ: Let me restate the question
and make sure I understand it. The question of the
addition of metoclopramide to the other
analgesic
like what we have been going around
about today, in
a factorial kind of design, what is the
evidence of
the additional benefit of metoclopramide
to the
underlying analgesic.
Did I understand your question correctly,
Dr. Bastings?
DR. BASTINGS: Yes.
DR. ALEXANDER: There are limited studies.
209
One study I will show is twenty years
old. That is
this slide here.
(Slide EB12)
It is a study by Tfelt-Hansen
looking at
the preparation Migravess which Dr.
Schapira noted
was aspirin plus metoclopramide. This was a
factorial study looking at Migravess,
aspirin and
metoclopramide, versus aspirin alone
versus
placebo.
You can see that this is a
modest
improvement of only 2 percent for a
two-hour pain
response rate in that study. A good small number
of subjects, basically 118 subjects,
treating three
migraine attacks.
There have been a number of
comparative
studies between these combinations and
even with
triptans that have shown generally equivalent
results in the treatment of migraine.
DR. KIEBURTZ: Thank you.
DR. SMITH: I want a little clarification
on the estimated risk of the TD with the
intermittent use because Dr. Bastings
mentioned, in
210
his talk, that there was an estimate of
380 cases
per million persons per year and then,
in the FDA
review, there was an estimate quoted
from the NDA
of 20 per million.
I am wondering what is the
estimate that
the company has and what is the basis
for their
estimate.
DR. ALEXANDER: Thank you for that
question because it needs
clarification. Back in
2004, when Pozen was preparing for the
meeting with
the FDA, the type A meeting, the
critical-path
meeting that you heard about, we were
looking at
the figure of 1 percent as the figure
that was
given to us in the not-approvable letter
as being
the upper limit of possibility. But is still a
figure of 1 percent.
That certainly is significant
when you
consider tardive dyskinesia. So we undertook to
try to estimate how much lower the risk
might
actually be. We looked at spontaneously reported
cases in the databases available. You have seen
the 87 cases or the 40 cases from the
Shaffer
211
article.
We also looked at estimates of
prescriptions or usage over a year's
period of time
and applied a multiplier for the
spontaneous
reported rate of, say, 1 percent. If only 1
percent of all incident cases are
reported, what
would the risk be? It is a conservative estimate.
In that way, we calculated the
risk could
be as high as 0.002 percent or something
like that,
just to make the distinction that it is
much less
than 1 percent. That has gotten carried over into
this discussion today and I just want to
point out
that it is based on estimates or
assumptions. The
better data are the actual-use data that Dr.
Schapira has shown with the use of
metoclopramide,
we think, in migraine in a large
population in the
U.K..
DR. SMITH: Let me just make sure I
understand. You are basing the estimates, these
lower estimates, on reporting rates to
adverse-events reporting systems in the
U.K. and
U.S.?
Is that correct?
212
DR. ALEXANDER: Let me just specifically
address the 0.038 percent risk that Dr.
Bastings
more recently used in this. That is based on an
estimate of a risk that was the most
conservative
that we could come up with based on the
data.
DR. SMITH: Okay.
Thank you.
DR. KIEBURTZ: I think we will talk about
that some more, too, when we address the
specific
questions. I want to ask one question and then we
are going to have to close, and this
might go to
Dr. Jinnah, if he is still here, or, if
you don't
know the answer.
I believe Dr. Jung brought
this up in
part.
In stimulant-induced sterotopy or models of
tardive dyskinesia, are there animal
models, and
this was alluded to in at least one
presentation,
as to whether single or a few doses, or
intermittent doses, could induce tardive
dyskinesias in animal models as opposed
to chronic
use.
Can you speak to this?
DR. JINNAH: I can.
I am familiar with
that literature. It is going to be difficult to
213
translate that literature which is
mostly derived
from rodents to humans because the types
of drugs
and the temporal course of drug delivery
in rodents
to create these movements that are
labeled as
analogous to TD are quite different.
So whether or not we should be even
calling it TD is at question. So I am not sure
that answering the question is going to
help.
DR. KIEBURTZ: Could you answer it anyway?
DR. JINNAH: Sure.
DR. KIEBURTZ: Here is my question. I
understand there are animal models. And I
understand that animal models don't
represent the
human disease. But I think it would be useful to
know whether or not tardive dyskinesia--or
those
movements have been induced with
intermittent or
few exposures are they are required to
have chronic
exposures for them to develop in models.
It doesn't necessarily,
therefore, mean
that the human experience follows that.
DR. JINNAH: Correct.
DR. KIEBURTZ: Let me put it a different
214
way.
My understanding is those models indicate
that intermittent or few exposures can
induce those
changes and reduce the threshold for
stimulant-induced stereotopies. Am I wrong?
DR. JINNAH: No.
That's correct. Either
chronic or intermittent administration,
as few as
just one or two doses of the drugs, can
induce
these movements that are called tardive
dyskinesia.
I should temper that statement with the
observation
that Reserpine is one of those drugs and
Reserpine
does not cause tardive dyskinesia in
humans, to my
knowledge.
So what the movements are, I
think, is
still really a key part of that answer.
DR. KIEBURTZ: So the specificity and the
meaning of these models is unclear.
DR. JINNAH: I think that is true. But,
perhaps, Dr. Jeste can comment on the
issue of
using neuroleptics intermittently in
psychiatry
because there is some data showing that
drug
holidays of neuroleptics and intermittent
use of
neuroleptics in human patients does, in
fact,
215
increase the risk of tardive dyskinesia.
But, again, it is not PRN or
intermittent
use as we have been talking about. It is more
chronic for weeks, months, maybe years
with a
holiday and then chronic again. So it is a little
bit different but the same idea.
DR. JESTE:
That actually applies to
people with schizophrenia or other
psychiatric
disorders when you do long-term
treatment. People
who get the treatment intermittently
seem to be a
high risk of developing tardive dyskinesia. The
theory is that has something to do with
kindling,
that if you administer something
continuously,
there is development of tolerance where
it is
intermediate. Intermittent administration may lead
to kindling and increase the risk of TD.
DR. KIEBURTZ: Thank you.
We are going to stop the
discussion period
at this point. Just to reiterate, to the point of
being boring, not to continue any
discussions of
the presentations not in the public forum.
We will start with the Open
Public Hearing
216
next.
All registered Open Public Hearing speakers,
please register at the Registration
Desk. 1
o'clock is when we will start again.
Let me just thank all the
participants
from the sponsor, from the FDA and from
the
committee for bearing with the way we
ran things.
We are adjourned until 1:00.
(Whereupon, at 12:00 p.m., the
proceedings
were recessed to be resumed at 1:00
p.m.)
217
A F T E R N O O N P R O
C E E D I N G S
(1:00 p.m.)
Open Public Hearing
DR. KIEBURTZ: The first part of the
afternoon is the Open Public
Hearing. I have a
statement to read here.
Both the Food and Drug
Administration and
the public believe in a transparent
process for
information gathering and decision
making. To
insure such transparency at the Open
Public Hearing
session of the Advisory Committee
meeting, FDA
believes that it is important to
understand the
context of an individual's
presentation. For this
reason, FDA encourages you, the Open
Public Hearing
speaker, at the beginning of your
written or oral
statement, to advise the committee of
any financial
relationship that you may have with the
sponsor,
its products and, if known, its direct
competitors.
For example, this financial
information
may include a company's or group's
payment of your
travel, lodging or other expenses in
connection
with your attendance at the
meeting. Likewise, FDA
218
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.
So far, we only have one
registered
speaker for the Open Public Hearing and
that is Dr.
Cynthia McCormick who can come on up to
the podium
and address the committee.
DR. McCORMICK: Thank you.
Good
afternoon, Dr. Kieburtz and members of
the PCNS
Advisory Committee, Dr. Katz, Dr.
Temple.
First let me start with the
disclosures
and also thank you for giving me the
opportunity
today to address the committee as a
member of the
public, which is a new experience for
me, and to
share with you my thoughts as you
proceed into the
deliberations for today.
So, in terms of disclosure, since
leaving
the FDA, I have worked as an independent
consultant
to regulated industry including upwards
of probably
219
close to 70 companies by now, many of
which are in
the area of pain therapeutics including
a few
companies developing drugs targeted to
treat
migraine. Among these, I have served as a
consultant to Pozen.
Today, however, I am speaking
on my own
behalf and my comments are not driven by
my
industry consultation but rather by own
personal
experience. The division has heard these, I think,
in some manner but probably not in this
context.
By introduction, I am a
neurologist and a
former federal employee, 17 years a
federal
employee, most of which was spent at the
FDA,
initially as a reviewer in the Division
of
Neuropharmacologic Drug Products, and
the remainder
as the Division Director in Anesthetic
Critical
Care and Addiction Drug Products where I
had the
responsibility, among other things, for
therapies
to treat various painful conditions.
As such, I have been in the position of
approving drugs before. I know that it is not
always straightforward and there is a
great deal to
220
consider. I also know that there is a fair amount
of discretion in making these decisions
and that,
perhaps, makes the decision-making even
more
difficult.
I think I have to say that
both approval
decisions and not-approval decisions can
have
important consequences for
patients. I believe in
the FDA process. I believe in the mission of the
FDA and I have enormous confidence in
the FDA.
With all of its oversight systems of
checks and
balances, high ethical standards, it
does, really,
a remarkable job in protecting the
public health,
both in not approving drugs that are not
effective
and safe and also in approving drugs
that are. The
job isn't without its struggles. The recent public
criticisms that FDA has had to endure
which, in my
opinion, are unwarranted, make it even
more
difficult.
But I am speaking to you today
not as a
former regulator but as a chronic
migraine patient.
I know what drugs are available, both
for
prophylaxis and for PRN treatment of
acute migraine
221
attacks and I have tried most of
them. I know the
side effects of the medications and I
have been
able to make informed decisions because
the FDA
process works and because product
labeling is
usually fair and very complete regarding
the risks
of medications.
So, two and a half years ago,
while I was
serving as FDA's Director of Anesthetic
Drug
Products, I suffered a serious,
potentially
life-threatening, adverse event from an
approved
migraine drug which I took on the day
before an
advisory committee meeting, much like
this one,
although the topic was prescription drug
abuse and
oxycoton which probably explains the
headache.
I found myself in the
intensive-care unit
and I have permanent sequelae from the
event. But
the thing is that it left me with no
realistic
treatment options for migraine and I, as
many
others, consider this a disorder that
can be very
incapacitating at times.
So consider for a minute what is currently
approved for the treatment of
migraine. Most of
222
the approved products are associated
with vascular
risk, as you might expect, including
significant
cardiovascular risk. These include the ergot
alkaloids, the triptans and, up until
spring of
this year, one of the selective cox-2
inhibitors no
longer on the market.
So, for patients who have suffered a
myocardial infarction, or who have
cardiovascular
risks, these medications really aren't
an option.
So what is left? Not very much. I think we heard,
when we saw the slide with three things
on it this
morning, well, eliminate one
column. So,
over-the-counter and off-label
medications. Those
are my choices right now. So, for people who have
no options, any therapeutic gain is
significant.
So, when you consider how to deal
with
what is an acceptable risk in this
population,
consider the following: the existing
medications
have risks that are not trivial. Patients who
suffer from migraines tend to know a lot
about
their medications and truthful labeling
is
absolutely critical and something they
expect from
223
the FDA and something the FDA expects
from
themselves, as well. Without it, they can't make
informed choices about their treatment.
To put into perspective the
kind of risks
that some patients are willing to take
with
migraine to get relief, take a minute to
consider
how bad the disorder can be. It took me several
years after the first triptan approval
before I was
willing to take one.
I listened to the
adverse-event profile
unfold during the NDA review because I
was in the
division that reviewed that drug. So when I
finally took one, I did it with my eyes
wide open,
with absolute full knowledge and
understanding that
there was a cardiovascular risk and what
that risk
might be. And I was willing to take that risk,
obviously, and I did.
But my headaches were so
debilitating at
that time, and so incapacitating and
really
impaired my ability to work, that I was
willing to
take that risk. So that is how bad it can be.
Here we are with an
armamentarium that
224
includes three, now, actually, two
classes of drugs
that are off-limits for a segment of the
population
like me, and few options. Right now, you are
discussing a drug that has a different
kind of side
effect.
It has been implicated with the potential
for having a risk of tardive dyskinesia
with
chronic administration.
I am a neurologist. I know what tardive
dyskinesia is. I have seen it. It is a bad
condition. It can be very debilitating. So the
question is is that worse than an
MI? I don't
know.
That is what I am asking myself.
I think
each patient has to make that decision
themselves
as to what risks are worse than others
and what
they are willing to take.
It might be, if there were
some benefit
that I could gain from that drug. But I can
absolutely guarantee that, if I didn't
get any
benefit from the drug on the first
administration,
I wouldn't be taking it more than
once. That is
one thing that I think we heard this
morning
about--that is pretty characteristic of
people with
225
migraine. We self-select our medications. You are
not very likely to accumulate a cadre of
patients
who are continually deriving no benefit
and only
risk.
So that is something to put into the
equation.
My message to the committee
and to Dr.
Katz is the following: please keep an
open mind.
Migraine can be incapacitating. For a segment of
the population, the drugs that are
currently
approved don't exist. While it would be ideal to
have criteria that would give us the
perfect drug,
patients like me don't expect perfection
and would
be very happy with any therapeutic
effect so long
as the labeling truthfully reflects the
risks as
well as they can be known.
Thank you.
DR. KIEBURTZ: Thank you.
Is there anyone else who would
like to
address the committee during the Open
Public
Hearing?
Not hearing any, thanking Dr. McCormick
for her statement, we will close the
Open Public
Hearing phase of this meeting.
226
Committee Discussion and Response
to FDA Questions
DR. KIEBURTZ: We will now, as a group,
deliberate the questions that were posed.
Committee members, just so you are
familiar, I
believe, just from my seating chart,
that Dr.
Porter is the only non-voting member.
So, on the five questions, we
have to
individually vote our opinion about the
questions
posed.
Some of them are multipart so it is going
to be a little difficult. We can discuss the
question and then we need to come to an
answer. At
the time you give your answer, or your
vote, you
can get some clarification as to why you
are voting
that way.
This will be a chance for the
agency to
get a clarification of how we are
thinking.
Here is the first
question. Take it as a
given that this has been estimated as an
annual
incidence--that is, the number of new
cases of
tardive dyskinesia--at this dose for use
of up to
six doses per month, so up to 72 doses
per year,
380 cases, new cases, of tardive dyskinesia
per
227
million patients per year.
Do you think this is a
reasonable
estimate? Dr. Fahn.
DR. FAHN: I would like to start. I did
some calculations on the margins of the slides that
were handed out. The risk for developing--the
incidence for developing tardive
dyskinesia has
been calculated by John Kane and his
colleagues at
Long Island Jewish who has studying the
epidemiological of tardive dyskinesia
for decades.
He calculated the risk to be
about 5
percent per year, so a person would
take--now,
these were neuroleptics, but these were
dopamine-receptor blocking agents which,
of course,
metoclopramide is also. The calculation was that 5
percent per year, that if you took it
for four
years, then you would have a 20 percent
risk of
getting tardive dyskinesia and so forth.
Multiply 5 percent per year
times 72 days
divided by 360 days, I come up with a 1
percent
risk, not 0.38 percent risk. Now, granted that the
drugs that were used in the psychiatric
population
228
are daily doses continuously, so that
might have
been the risk for 72 days in a
continuum. What
would happen if it was
discontinuous? I think this
is the big unknown. I don't think anybody, as we
heard all day so far--that no one really
knows what
these intermittent or periodic risks are
and it may
be less.
The intermittency, when you
stop--for
psychiatric patients, of course, and
then restart
it, the risk seems to go up. But, giving it for
migraine is one thing. So I think this a level
that is probably too low. I think it, at least
from these calculations, is going to be
probably
closer to the 1 percent risk.
If you want me to address the
second part
of that question, I would be glad to do
that.
DR. KIEBURTZ: Let's just stick with this.
I mean, we can have a little bit of
general
discussion about whether we think it is
reasonable
or not, and then we are going to have to
just each
vote about that question.
Dr. Jeste, did you--
229
DR. JESTE: Actually, unrelated in a way,
but one general point I want to
make. Since the
morning, there has been a lot of
discussion of how
do we define tardive dyskinesia. I would argue
that there is, actually, a standard
definition in
the DSM IV for tardive dyskinesia. By definition,
as Dr. Jinnah said, that is later
occurring. The
word "tardive" means late
occurring.
So, if it occurs in less than
a month, it
should not be tardive dyskinesia. That doesn't
mean it cannot be persistent. So we need to
separate out tardive dyskinesia from
persistent
dyskinesia. Acute dyskinesia can be persistent but
we should not call it tardive
dyskinesia. I think
it is somewhat of an oxymoron to say
tardive
dyskinesia that develops after one day
of
treatment, of any drug, for that matter.
The DSM IV definition is
minimum 90 days
except for older people where it is 30
days or
more.
One can use different definitions for
possible different types but, again, in
terms of
standard nomenclature, I think we should
stick to
230
that definition. That would be my recommendation.
DR. KIEBURTZ: Dr. Porter.
DR. PORTER: Yes.
An epileptologist
should never tackle a movement-disorders
expert in
his own field, but, Stan, I think that
you have
gone way too high.
I think that, if it were
really 1 percent
for this particular drug in migraine, we
would be
seeing 95 patients every year showing up
in the
U.K. yellow-card system. While I think maybe the
U.K. yellow-card system is flawed, I
think that it
is not nearly that flawed, especially
when the dose
given in the U.K. is more than twice the
dose as
proposed for the tablet here in the U.S.
So I think it is--actually, I
think that
the company's estimate is high and I
think your
estimate is very high.
DR. SMITH: I want to comment, because my
area is pharmacoepidemiology, and I feel
that these
databases are kind of being maligned and
misused.
I want to really make sure that that is
understood,
that the use of reports and divided the
number of
231
cases is, first of all, not what these
databases
are meant for. It is a gross misuse of them and it
is a very dangerous misuse, particularly
in this
case.
If anything, it is probably the lowest
ballpark estimate of what the risk might
be and it
is not even a good estimate at that.
One of the things we are
pretty much, I
think, in agreement on without even
voting is that
it is not a simple disease to diagnose,
that there
is variation in what makes a diagnosis
of TD, that
part of the diagnosis criteria does
include, in
some places, the length of therapy which
would
preclude people from reporting something
it if
was--as TD, if it was after just one or
two uses,
so we don't even know. So the reporting rate for
that would be substantially lower than
what we
think.
The drug has been on the
market a long
time.
It is labeled for this so it is not
unexpected. So estimating the reporting rate is
just--it is just a guess. It is like throwing an
arrow.
We don't know if it is 1 percent or
232
10 percent or 1 millionth of a
percent. It is a
gross unknown and I think this is
something we
really have to think about whether or
not these
numbers are based on anything that is
reasonable.
DR. LENAERTS: When we consider the risk
of tardive dyskinesia or other movement
disorders,
would it be appropriate, so that is a
question to
anybody, or a comment, to consider the
relative
risk of migrainers where, on the one
hand, we have
probably a relatively younger
population. But, on
the other hand, we have significantly
more women
with a 3-to-2 ratio of women to men, and
also the
fact that the coadministration of
tricyclic
anti-depressants and the SSRIs which we
have seen
can give its own risk is particularly
common in
that population of patients.
If I take the numbers that you
showed, on
67 cases of TD, 14 also took
anti-depressants which
between 20 and 25 percent. Is it appropriate to
consider the special population that
migrainers
represent in that context?
DR. KIEBURTZ: Sure.
I think we should.
233
Dr. Green.
DR. GREEN: I think that dopamine
hypersensitivity is right at the heart
of migraine
pathophysiology and, therefore, it is
not clear to
me that any data we get from the general
population
rather than the migraine population is
relevant to
this question.
I don't know if that impacts
negatively,
positively, or not at all. But this is a condition
of dopamine hypersensitivity. But also the other
comment is I agree with several comments
that there
is a huge need for a medication that is
effective
in the treatment of migraine that is not
vasoactive, a desperate need for that.
DR. KIEBURTZ: Dr. Hughes.
DR. HUGHES: I try to explore the issue of
the safety study that the company had
done this
morning.
I think--you know, you have got 300
subjects followed for a year and 1,000
followed for
a
few months. I think it would be hard to
conceive
of the idea that the true rate would be
1 percent
or more, given that they didn't really
see any
234
events or they saw zero events according
to the
definition that they were using.
So I would hazard a guess that
it is
somewhat below 1 percent. But how much below, who
knows?
DR. KIEBURTZ: One last comment.
DR. JESTE: I really think it is fair to
say we do not know the risk and we will
not know
the risk unless and until we do a
longitudinal
prospective study in which rigorous
measures are
used to find out whether the patient has
TD and one
has to use a scale like involuntary
movements
scale, use some fixed criteria.
There are a number of
confounds in
deciding the incidence of tardive
dyskinesia. For
example, the drugs that produce TD are
also the
drugs that are suppress it. So, if we increase the
dose, you may not see TD.
It also depends on what other
medications
the patients are taking. If they happen to be on
dopaminergic drugs, for example, that
might
precipitate TD. If you look at the history of the
235
neuroleptics in psychiatry, it is worth
remembering
that it took more than 25 years before
the field
accepted that there was such a thing as
tardive
dyskinesia.
People argued that it was a
symptom of
schizophrenia for many years. The only time that
the incidence became clear is when a
number of
people did longitudinal prospective
studies using
that.
So I really don't think anybody can make a
claim for any kind of--whether it is
lower or
higher, it doesn't matter. We just don't know the
risk at this stage.
DR. KIEBURTZ: Okay.
So we are going to
vote now. I am going to go around the table, which
is, this is the proposed estimate, 0.038
percent,
as an annual incidence. Do you think it is a
reasonable estimate. We don't have a definition of
reasonable, but let me operationalize
that. If we
are proposing 0.04, there is some range
around that
from 0.01 to--an order of magnitude
around that.
But you have a sense of where the estimate
is.
Go ahead. Dr. Green? It is either yes, no or
236
abstain.
But you can make a comment.
DR. GREEN: The answer is no.
DR. KIEBURTZ: Dr. Jeste.
DR. JESTE: I don't think, really, there
are any data to say this is a reasonable
estimate
at this stage.
DR. KIEBURTZ: So the answer is no.
DR. JESTE: The answer is no.
DR. SMITH: No.
DR. WELCH: No.
DR. LENAERTS: No.
DR. FAHN: No.
DR. JUNG: No.
DR. GOLDSTEIN: No.
DR. SACCO: No.
DR. KOSKI: No.
DR. HUGHES: No.
DR. KIEBURTZ: I will say yes because I
think we don't know but, from the
evidence, we have
some reasonable bounds, as Dr. Hughes
alluded to,
that we certainly don't think it is 1.0
or higher.
It is somewhere under that. We don't have enough
237
evidence to conclude it is zero, but what
is in the
reasonable range of between zero and 1.0
and I
think this is reasonable.
Dr. Temple.
DR. TEMPLE: Could I ask whether the
people who said no think it might be
lower, higher
or just can't say.
DR. KIEBURTZ: I am going to do a show of
hands.
How many people think you just really can't
say.
There is not enough evidence to say, and that
is why you voted not. (Show of hands.)
DR. KIEBURTZ: That is seven.
DR. TEMPLE: I interpret that as meaning
they think it could actually be
higher. Would that
be--
DR. KIEBURTZ: Just don't know. Dr. Fahn,
do you think it is higher?
DR. FAHN: I think it is higher.
DR. KIEBURTZ: Dr. Lenaerts does too.
Three people think-- does anybody think
it is lower
than this estimate?
(No response.)
238
DR. KIEBURTZ: Okay.
Is that helpful to
you?
DR. TEMPLE: Yes.
DR. KIEBURTZ: I am just going to reverse
the order a little bit here in the next
set of
questions because I think one moots the
other. So
let's just go to the third question
here. Is any
risk of tardive dyskinesia acceptable
for a
migraine population? If we conclude that there is
none, the middle question, is not--so, just
logically, I would like to go with that
question.
I know Anuja is going to be mad at me
for going out
of order.
Any discussion about that?
DR. GOLDSTEIN: It is a takeoff on one of
Dr. Matchar's slides, actually, where he
said 79
percent of sufferers showed an interest
in trying a
novel product with similar efficacy but
fewer
adverse events than existing migraine
medications.
The point is that this is
obviously
another imponderable. We heard testimony that some
people might take that risk, whatever
that risk
239
could be defined. But it is possible, through
decision analysis, to get some bounds
for what the
people might--what patients might be
able, or
willing, to accept as a risk for having
a permanent
or even a transient sequela.
So, right now, we are just--we
are making
this up as we go along. But there is a way to
actually get data to be able to address
that point.
What I would encourage would be to try
to formally
get that type of data. The studies are not that
difficult to do.
DR. KIEBURTZ: Dr. Koski.
DR. KOSKI: No; not right now.
DR. KIEBURTZ: Dr. Fahn.
DR. FAHN: I think the risk of getting
tardive dyskinesia on the first dose is
extremely,
extremely, rare and even the second dose
and so
forth until you start taking multiple
doses. So,
when Dr. McCormick made her presentation
about
migraine sufferers would not continue a
drug if it
wasn't working, that shed a new light on
me. I
mean, that is an experience--they are
not going to
240
keep on taking this drug.
Therefore, I think the risk, then, is not
for the people who it doesn't help
continuing to
take it.
The risk, then, becomes those in which
the drug helps and then the drug, as
they continue
to take it, the risk keeps going up
every time they
take it.
But, because a drug is
beneficial to those
patients, then I think the risk is
probably worth
it for those people. Therefore, even a 1 percent
risk in a year, if it helps the patient,
that may
be something the patient has to decide
and they
know what that risk is and would take
it.
So, therefore, I think the
answer to this
is yes.
Risk is acceptable for the migraine
population at least that gets a response
to the
drug.
DR. KIEBURTZ: Dr. Welch.
DR. WELCH: My answer to this would be yes
as well.
It depends on the migraine population and
the way the drug is used. For migraine patients
with severe disability that haven't
responded to
241
anything else, or there are
contraindications to
using such a medication, then this would
be a risk
worth taking. So my vote would be yes.
DR. KIEBURTZ: Dr. Green.
You don't have
to say about your vote yet. We are just doing
general discussion. But you can if you would like.
DR. GREEN: Again, in this special
population where vasoactive migraine
therapies are
not an option, it is wonderful--it would
be very
useful to all of us to have additional
options. I
would disagree, however, with the
comment that
migrainers don't overuse, or wouldn't be
likely to
overuse, something that is
ineffective. In fact,
it has been my impression that
migrainers are less
likely to overuse something that is
fully effective
and less likely to overuse something
that is
completely ineffective and the things in
the middle
which give partial relief are the things
which put
people at risk for redosing.
DR. KIEBURTZ: Dr. Temple.
DR. TEMPLE: Because you skipped to the
third question, there is no context here
about the
242
magnitude of the benefit from the thing
that puts
you at risk. This drug is going to work on people.
It is obvious. Naproxen works in migraine just
like ibuprofen and aspirin work in
migraine. So
there isn't any question it is going to
work.
The question that was flagged
there is how
much is it worth to you to get the added
benefit of
the metoclopramide. That should be kept in mind, I
think, even in this part, though.
DR. KIEBURTZ: I think it is pretty
obvious we are going to get to the third
question
because it doesn't look like there is
consensus.
Dr. Koski.
DR. KOSKI: I really would like to second
that.
In the sense that patients, because of the
fact that they can get a response from
naproxen,
are going to get something, or at least
a
significant portion of patients will get
something
in response to the drug.
The question is is there
something
additional that is taking place with the
metoclopramide addition. Because of that reason, I
243
sort of disagree with Dr.
McCormick. I think that
this would not be a one-time event, that
this would
be something that people might continue
to take.
Certainly patients I have
seen, some of
them, quite frankly, think if one tablet
works
okay, maybe they should take two and
then,
occasionally, maybe I have
something--maybe it is
coming on and I am always told to take
something
just as soon as I possibly can. I will take
another one then.
So I think there is a great
deal of
potential for that type of abuse.
DR. KIEBURTZ: Let me just clarify the
question, here, too, which is not a
product-specific question. Is any risk of tardive
dyskinesia acceptable for a migraine
population?
It is a question that is independent of
benefit.
That is why I went there first. But it is a very
abstract question, as I read it. But maybe I am
reading it wrong.
Dr. Jung.
DR. JUNG: Speaking as the consumer
244
representative, my concern is that there
would be
adequate patient education information
about what
actually tardive dyskinesia is, given
the fact
that, in this room of neurologists, we
can't seem
to agree how you actually make a
diagnosis. How do
you anticipate that, in your office, you
are going
to be able to explain to a patient or be
able to
show a video, for example, such as was
shown
earlier, of what a significant risk is.
I think most people can
understand the
risk of what a heart attack or a stroke
is. But to
describe tardive dyskinesia and have the
worst-case
scenario be apparent is not clear to me,
that we
can actually do that in the clinical
setting.
DR. KIEBURTZ: Thanks.
Dr. Welch, did you have a
comment?
DR. WELCH: No; I was going to address--
DR. KIEBURTZ: Okay.
Dr. Sacco.
DR. SACCO: I think we have other data
from other patient populations that
obviously have
accepted the risk of medical
metoclopramide for
GERD.
So I think it depends on probably the amount
245
of risk.
Any risk is really tricky if it is 0.0001
and the benefit. So it is a risk/benefit ratio
but, in my mind, the fact that other
patient
populations with pain somewhere else,
including
gastroesophageal reflux, have accepted
the risk of
the medicine that is out there, then any
risk may
be acceptable. But it depends on the amount.
DR. KIEBURTZ: Dr. Smith.
DR. SMITH: I want to agree that just to
say is there risk without thinking about
the
benefit, it just can't be separated
unless you are
talking about cure and a one in a
million risk.
Then maybe the answer could be yes. But I agree
that you have to think about what is the
added
benefit when you know you are going to
add this
risk beyond what is already out there.
DR. KIEBURTZ: Maybe I misread this third
question.
Maybe it is meant to be contextualized
on the second question and not stand
alone. Is
that true?
DR. KATZ: No; I think you read it
correctly. We wanted to find out if it is just
246
drug independent. But, of course, obviously, the
amount of risk you are willing to
tolerate will
depend on what you think the benefit
is. That is
obviously critical. But we just wanted to sort of
get a baseline because, as you say, it
moots the
rest of it if everybody thinks no risk
is
acceptable, no level of risk.
DR. KIEBURTZ: So let's vote the question
because I think we know the answer to
this. Is any
risk of tardive dyskinesia acceptable
for the
migraine population? We will go this way this time
to mix it up. I say yes.
DR. HUGHES: Yes.
DR. KOSKI: Yes.
DR. SACCO: Yes.
DR. GOLDSTEIN: Yes, with just the
additional comment that, again, there is
a way to
get the information so that we are not
guesstimating. We can get this.
DR. JUNG: With some hesitation, yes.
DR. FAHN: Yes.
DR. LENAERTS: Yes, too, but for the same
247
remark.
It depends on the efficacy. It is
hard to
take out of context.
DR. WELCH: Yes.
DR. SMITH: A qualified yes.
DR. JESTE: Yes.
DR. GREEN: Yes.
DR. KIEBURTZ: Back to Question 2 which is
a little more complex. I think what we are to do
here is to assume that the risk of MT100
is 0.04
percent, let's say.
DR. KATZ: That is what the question asks.
But it turns out most people don't think
that that
is
a reasonable risk. Some people think it
is
higher--or a reasonable estimate of the
risk. So I
am not sure we want to sort of pin our
risk/benefit
consideration on some risk estimate that
nobody
believes.
Maybe the best thing to do is just sort
of--I mean, everybody has probably got
their own
personal view of what they think the
risk is. You
can't tell. I think maybe we should try to talk
about what sort of a--let's assume the
benefit part
248
of this question, the 5 to 10 percent
contribution
of the metoclopramide and then sort of
talk about
what sort of risk you think would be acceptable.
That is really more or less
the question,
and whether or not we think we are at
the point yet
where we think that that is the risk.
DR. KIEBURTZ: Okay.
DR. KATZ: In other words, I don't want to
link it to a number which everybody has
already
decided doesn't mean anything.
DR. KIEBURTZ: The way that we were
discussing the last question it got
posed
around--several people volunteered it
depends on
how much benefit you are seeing. So let's turn it
around and say, in the factorial
designs, leaving
aside the question of statistical
significance, the
proportion of individuals as reported as
the
percentage of individuals who had sustained
pain
relief at 24 hours differed in the MT100
group
versus the naproxen group by between
3--let's say
between 4 and 6 percent.
So between 4 and 6 percent
additional
249
subjects had sustained pain-free
response.
DR. BASTINGS: It is not pain-free. It is
just sustained pain response.
DR. KIEBURTZ: I mean sustained pain
response. Thank you for the clarification. We are
assuming that is true, that is the true
effect, for
the purposes of this hypothetical
discussion.
DR. BASTINGS: You also need to take into
consideration that there would be no benefit
at two
hours, which is--
DR. KIEBURTZ: So that is the
parenthetical statement below which is,
if you
looked at the comparison of MT100 to
naproxen at
the two-hour pain response, those
differences were
not statistically significant. They were
numerically different but they were not
statistically--Dr. Bastings'
presentation showed
that in that, in the one study, quite a
number of
people had a lower relapse rate and that
added up
to the total difference between the
groups.
In the second study he
presented, the
majority of it was actually in the
two-hour
250
response and there wasn't that much
difference in
the relapse rate. But the numeric difference, even
at two hours, was 3.1, I think, if I
remember
correctly.
So the comparisons at two-hour
pain
response are not statistically
significant. So,
overall, the effect is 4 to 6 percent
but the
two-hour comparison of pain response is
not
significantly different.
Have I framed the question
correctly? We
are changing on the fly here.
DR. KATZ: In our hands, the way we have
analyzed it, the studies which we
believe were what
the protocol said, the contribution of
metoclopramide for a sustained response,
which was
the primary outcome, is not
statistically
significant overall. It only seems to be nominally
significant when you look at the
non-nausea
baseline subgroup which is partly where
this 5 to
10
percent comes from.
There is a 10 percent
contribution of
metoclopramide in the non-nausea at
baseline
251
subgroup which, again, is normally
significant in
two studies. We don't think that that is true
replication but, in the overall group,
we don't
think that the contribution, even for
sustained
response, is statistically significant
DR. KIEBURTZ: I wasn't suggesting that
you did.
DR. KATZ: Okay.
DR. KIEBURTZ: Everyone has got this
definition here. So the question is what amount of
risk would be reasonable for that amount
of
clinical benefit. So we are not saying is that
risk reasonable. We are saying what is reasonable
with that amount of benefit, if you can
follow the
hypothetical situation.
DR. SACCO: I just want to be sure. It
sounds like, in the hypothetical
situation, we are
giving the compound more benefit than
what is seen,
5 to 10 percent, the way this question
is phrased,
and I understand where you may be getting with
not-nausea is to--and possibly an
exaggeration of
the benefit.
252
DR. KIEBURTZ: Okay.
DR. SACCO: If we take what we got, which
was 4 to 6 overall, this question is not
phrased as
just in those without nausea. So you are giving it
the benefit--
DR. KATZ: No; right.
It is not. But the
range, 5 to 10 percent, includes--so the
estimate
that was in the overall population and
the maximum
difference that you saw in the no
nausea. We could
talk about whether or not a study ought
to be done
to replicate the no-nausea subgroup of
whether
another study or studies should be done
in the
overall, but we just want to know, is
there some
well-defined population in whom the
contribution--to be determined what that
is--if the
contribution of metoclopramide is in
this range, as
a ballpark, because that is where the
estimates
have sort of fallen out. Are the risks, whatever
they are, acceptable?
So I think of this range. We could figure
out which population we think that range
applies to
down the road.
253
DR. TEMPLE: Our assumption is that there
is not going to be a bright line between
5 and 10
percent.
They are both fairly modest. One
is more
modest than the other, but that is a
reasonable
ballpark to think about. If there is a bright line
that you have, say so.
DR. KIEBURTZ: Dr. Welch and then Dr.
Fahn.
DR. WELCH: Well, let's try and instill
some practical clinical reality into the
question.
Surely what the question is saying is if
there is a
small subpopulation, and it would be
small at this
level of 10 percent improvement, that
responds to
metoclopramide plus naproxen that
doesn't respond
to naproxen and that that can be
significantly
proven, and if you have answered yes to
the risk of
tardive dyskinesia acceptable for a
migraine
population, the answer would have to be
yes for the
second part because you have said that
you will use
this drug, or certainly you would use
metoclopramide, in a particular
population that has
benefit that can't take anything else.
254
So the issue here is, have you
really
proven that metoclopramide plus naproxen
is, in
fact, statistically significantly
different in a
subpopulation. I would suggest that it has not
been proven that 5 to 10 improvement is
in the
nausea versus no-nausea, and we are
going to talk
about that later. But, to me, that is not a stable
measure as yet.
But, if it was, there is one
in ten
patients who responds to naproxen plus
metoclopramide that wouldn't respond to
naproxen,
then you would use naproxen because
there is
nothing else yes, the answer would have
to be yes.
DR. FAHN: That is the point I was
essentially going to make and that is
what I was
going to ask the FDA, if this drug were
available
on the market, if it was restricted to
those who
were, on naproxen alone, failed and then
they still
had that 5 to 10 percent chance of getting better
with this combination, then I think the
answer is
yes.
If it is just going to be open
and anybody
255
can take the drug without even trying
naproxen
alone first, then the risk for tardive
dyskinesia
is too great for me. So I assume there will be
some kind of restriction that they have
to be
tested first with naproxen alone
because,
otherwise, I think the risk would be too
great.
But if it is restricted that way, then I
say, this
is a worthwhile risk.
DR. KIEBURTZ: Let me just refocus things
again.
By pursuing this hypothetical question, we
are not agreeing that there is a benefit
of MT100
over naproxen. We are just saying hypothetically,
if it were so. We are not agreeing that we think
that that has been shown. So I just want to make
that one statement.
Two is I don't think we can
assume that we
know how the restrictions are going to
be. That is
not how this conversation, I don't
think--
DR. FAHN: I think the point is if more
people will be exposed to this, then
more people
are going to get tardive
dyskinesia. But if the
exposure is limited to those people in
which this
256
drug may be the only thing left, then it
is a
reasonable risk.
DR. KIEBURTZ: Dr. Porter.
DR. PORTER: I completely agree. If you
look at the history of cancer
chemotherapy of these
kinds of incremental improvements are
what have
made a lot of cancers much less a threat
than they
used to be. I think that we would have to take
these little bites when we can get them.
I agree fully with the thesis
that this is
a drug that, A, has to be proven. I am not sure
about this business about whether or not
the nausea
is or is not related to its
efficacy. I agree with
that.
Certainly, there will be some labeling, I
hope, that would be relatively strong
relative to
the risk we have been talking about.
But I think to reject the drug
when it
might help some people who have gone
through a
parade of migraine drugs would be unfair
to them.
DR. JESTE: I am not a migraine researcher
but, based on my experience with
psychiatric
patients, just a couple of points
here. The one is
257
that the risk of tardive dyskinesia
varies from one
patient group to another. Clearly, elderly
patients, the risk is 30 percent
incidence with
conventional neuroleptics compared to 5
percent in
younger adults. So something like that will have
to be taken into account.
Secondly, all tardive
dyskinesia is the
same.
It can be pretty mild which is not a
problem, or it can be pretty serious
when it does
become a problem. So it depends, really, on what
kind of tardive dyskinesia and what
population. So
those will need to be taken into account
in
whatever final decision is made.
DR. KIEBURTZ: Dr. Bastings.
DR. BASTINGS: I would also like people to
comment, if possible, on the fact that
there would
be no effect on two hours but yet there
would be an
effect demonstrated in a sustained
endpoint. The
sustained endpoint is a measure which
includes
two-hour pain response. There is a possibility to
have a significant effect on sustained
response
without actually having an effect on the
two-hour
258
pain response which is a particularity.
I would like to have some
idea, in that
context, if that is an acceptable
outcome measure.
DR. GOLDSTEIN: Again, just to interject a
little clinical thought that, let's say,
if you
were a patient and you were having a
migraine and
you took this and in two hours you
weren't having
any benefit. Chances are you might, then, take
something else. You might just take naproxen
alone, for example, or some other
nonsteroidal
alone.
So the question I would have, as these
trials go on, from a practical
standpoint, would be
is that kind of additional dosing
factored in to
the 24-hour improvement because, if you
factor that
in as well, then the clinical benefit
might even be
less or, in that subpopulation of people
who don't
respond to that second added drug, the
benefit
might even be greater.
It is hard to know without
that
information. They may have it but I don't know--we
didn't see the data that way. But that, I think,
would address the question that you are
asking
259
here.
Nothing at two hours; then is there
sustained relief. I think you have to see what
else was done at that two-hour
standpoint to know
that.
DR. KIEBURTZ: That would be a relapse if
you had to take anything.
DR. GOLDSTEIN: Yes.
DR. TEMPLE: In these studies, as
conducted, and acknowledging that SPID
and TOTPAR
might give you slightly different
impressions, but
nobody would know the difference between
this drug
and naproxen as near as we can tell at
two hours.
So I think the question being raised,
and it is
part of it, is when you think of
somebody with a
terrible migraine that won't go away,
you think of
the early response mostly.
Mostly that is just naive and
we should
have been thinking about the sustained
response all
the time. But part of the question is is this
modest effect on that endpoint and not
on the
two-hour endpoint worth a certain amount
of risk of
TD.
We are not saying no, but we want to gain some
260
impressions of what you think.
DR. KIEBURTZ:
This is a very tricky
question and we are modifying it en
route. But the
trickiness of the question lies in how
big the
benefit is and the fact that the benefit
accrues on
a synthetic measure, one that incorporates
both
immediate response and relapse into a
single
measure when you have benefit on that
but no
benefit on the immediate measure, if I
am--
DR. KATZ: That is right with regard to
the contribution of the
metoclopramide. It is
obviously complicated because you could
construct
maybe a better 24-hour
sustained-response in which
you say--right now it is just you are
considered a
responder if you responded at two and
throughout
the next 22 hours. But, at two, the drug might not
be better than placebo so you wouldn't
win on the
typical thing.
But you could construct a
sustained-response outcome which says
you have to
beat placebo at two hours and--it is a
two-part
outcome--and you have to win on the next
22 hours
261
as well.
So you could do that. But it is
complicated because it is possible that
the drug,
itself, MT100 could win on that
particular outcome
but the metoclopramide doesn't
contribute to that
particular outcome. So you have to see what would
happen if you did that.
DR. TEMPLE: There is no doubt that the
whole drug has an effect at two
hours. Nobody is
doubting that. It is all about the contribution of
the metoclopramide.
DR. KATZ: Right.
So the question is do
you think the metoclopramide has to
contribute for
the two-hour point as well as the
sustained portion
of it or is it okay if the drug overall
wins at two
hours on this new sustained but the
metoclopramide
only contributes to a part of it.
DR. WELCH: Again, I don't believe that it
has been established yet that there is
an efficacy
so it is an assumption. So now you are talking
about what kind of efficacy measures you
would like
to see.
I would like to see a two-hour pain-free
sustained. I think that is the rigorous measure
262
and I think that, to show a difference
between
MT100 and naproxen, pain free at two
hours.
DR. KIEBURTZ: Dr. Bastings.
DR. BASTINGS: I would like also to point
out that this does not even include the
issue of
the effect on relapse or use of rescue
medication
such as in the factorial studies of the NDA,
there
was no significant difference for
relapse or use or
rescue medication either. It is just the combined
effect which gives you an effect.
DR. KIEBURTZ: So if you split the
combination thing of immediate response
and relapse
rate, neither of the individual
components was
significant. But when you combined them, that was
the only measure in which you achieved
significance.
We are going to vote this question.
What
question are we voting? Let's vote this question
which is, if MT100 were to carry the
same risk,
would such a risk be acceptable if the
only
contribution of the metoclopramide is a
5 to 10
percent improvement on the sustained
headache
263
relief with no improvement on the
two-hour
endpoint.
DR. WELCH: Can you just qualify this
question a little bit because the
question is in
the question. If you put with no effect on a
two-hour endpoint, I would have to say
no. But if
you really said that there is a 5 to 10
percent
improvement on sustained headache relief
as defined
by two hours pain-free and then no
relapse, then
the answer would have to be yes.
DR. PORTER: 5 percent to 10 percent of
patients?
DR. WELCH: Yes; 5 percent to 10 percent
of patients. It is not 5 to 10 percent--which is
critical here because it is extra
patients who can
respond who would not have responded as
opposed to
5 or 10 percent more pain relief. It is very
critical.
DR. KIEBURTZ: Let me just clarify. The
question is what the question is, not as
you
modified. I know that it not the question you want
to answer. But this is the question.
264
So, Dr. Green.
DR. TEMPLE: Just one thing. But it is
all about the contribution of
metoclopramide.
DR. KIEBURTZ: Right.
DR. TEMPLE: Nobody doubts that the whole
drug works in two hours.
DR. KIEBURTZ: It is the contribution of
metoclopramide, 5 to 10 percent, on the
sustained
measure with no effect on the two-hour
measure
which is not pain-free. It is just pain relief.
DR. GREEN: Okay.
Then I would say no.
DR. JESTE: No.
DR. SMITH: No.
DR. WELCH: No.
DR. LENAERTS: No.
But I would like to
make a comment, if I may, afterwards.
DR. KIEBURTZ: Go ahead.
Comment now,
please.
DR. LENAERTS: Of course, I just want to
clarify that, but we are really not
talking about
taking people who have not responded to
naproxen
alone because that would be--it gave the
265
impression, sometimes, in the discussion
as if we
were heading that way.
The other thing is even though the
outcome
of how they do at two hours and how they
do between
two and 24 are both important. But, as far as my
experience and my reading on the
subject, it is
clear that the weight of the two-hour
response is
much more significant than that of the
two to
24-hour period.
DR. FAHN: I got a little confused now in
the discussions. I thought that this was the added
benefit of having metoclopramide on top
of
naproxen, you get another 5 to 10
percent of
patients getting better with less
headache. So, on
that basis, I think that is yes.
DR. JUNG: No.
DR. GOLDSTEIN: No, not as this question
was written.
DR. SACCO: I am still confused about the
question. But I am going to say yes because I am,
first of all, reading it that if MT100
were to
carry the same risk, and I am reading that
risk of
266
TD as being 0.038 percent--am I correct
in my
assumption?
DR. KIEBURTZ: Yes.
DR. SACCO: Which is, I think, lower
than--
DR. KATZ: The way I would think of it, or
the way I think we would want you to
think about
it, is assume, again, the benefit
portion of this
is true, the 5 to 10 percent, not at two
hours but
on sustained--assume all that is
true. But we have
already determined that nobody believes
0.038. So
why would we want to link it in a
risk/benefit sort
of consideration.
I would say whatever you think
the risk is
now. Do you think the risk--
DR. SACCO: See, that's--it is a
risk/benefit question.
DR. KATZ: It is.
But these are the data
we have.
So we have to make a decision based on
these data. You might decide, well, since we don't
know what the risk is, I can't say yes
to this, or,
since I believe that the risk is pretty
low,
267
whatever I personally think it is, it
would be
worth that risk. You have to make an individual
decision based on what you believe the
risk data
are.
They are what they are. We can't do
anything about that.
DR. SACCO: Because I was looking at these
questions as true hypotheticals and
reading them
very literally, it sounds like, then--my
answer to
this is conditional on what I believe
the risk of
TD is.
DR. KATZ: Absolutely.
I think is how you
have to answer it.
DR. SACCO: So then I revise my answer and
I would say no.
DR. KATZ: Let me just say I think
everybody should address the question
that way and
if the previous no's were assuming
0.038, maybe we
need to--
DR. KIEBURTZ: We will go back. Dr.
Koski?
DR. KOSKI: I think specifically, since
268
one of the things that I was concerned
about had to
do with something that Lily actually
mentioned and
that is if you split up all of these
extrapyramidal
disorders, you know, whether they come
on rapidly,
as long as they are persistent, I think
they need
to be grouped together because that is
going to
have some impact on the patient. So my response
would be no.
DR. KIEBURTZ: Dr. Hughes.
DR. HUGHES: I would respond yes,
particularly if it was at the upper end
of the
range, towards 10 percent.
DR. KIEBURTZ: My vote is no.
Still no?
DR. GREEN: No.
DR. KIEBURTZ: Still no?
DR. JESTE: No.
DR. KIEBURTZ: Still no?
DR. SMITH: No.
DR. KIEBURTZ: Still no?
DR. WELCH: No.
DR. KIEBURTZ: Still no?
269
DR. LENAERTS: No.
DR. KIEBURTZ: Yes still?
DR. FAHN: Yes.
DR. KIEBURTZ: Still no?
DR. JUNG: No.
DR. GOLDSTEIN: No, again with there being
no effect at the two-hour endpoint
because the
reason for that was that I think those
patients
would take another rescue medicine where
we have
heard that there is, then, probably no
benefit.
DR. KIEBURTZ: Did you get the information
you wanted from the discussion and the
voting?
DR. TEMPLE: What I hear is that, assuming
that benefit as described, not much or
nothing at
two hours and something at 24 and
longer, and in
light of what you will each individually
think the
risk of TD or persistent dyskinesia
might be, you
are saying no.
DR. KIEBURTZ: I believe that is what you
heard.
DR. WELCH: The reason being is that if
you don't have a difference at two
hours, then you
270
can't prove that it is a metoclopramide
effect and,
therefore, you shouldn't be putting the
patient at
risk.
DR. TEMPLE: Why can't you attribute the
overall benefit at 24 hours to the
metoclopramide?
That is the only difference between the
two groups.
DR. WELCH: There may be other factors in
between which you can't stratify for.
DR. TEMPLE: Okay.
But presume it is a
properly randomized trial and everybody
is treated
exactly the same way in all other
respects, the
usual concerns one would always have, I
guess we
thought if they could actually win in a
persuasive
way, you would have to attribute it to
the
metoclopramide and the main question was
how
valuable is that in light of a certain
amount of
risk.
But I guess we thought that if
they did
the study properly in one, you would
attribute the
difference between
metoclopramide-naproxen and
naproxen to the metoclopramide. But I think we
understood what people were saying.
271
DR. KIEBURTZ: Okay.
To summarize. The
vote on Question 1 was one yes and 11
no's with no
abstentions. Question 2 is two yeses and 10 no's
with no abstentions. It was all yeses on the third
part of Question 1.
I think that is the hard
part. We'll see.
We are going to go on to Question 2; Is
there
sufficient evidence that the chronic
intermittent
administration of metoclopramide does
not carry a
risk of tardive dyskinesia. If we don't have any
discussion, we can just vote it. So we are just
going to vote it because I don't see
anybody who
wanted to discuss it.
Is there sufficient evidence
that chronic
intermittent administration of
metoclopramide does
not carry a risk of tardive
dyskinesia? I note no.
DR. HUGHES: No.
DR. KOSKI: No.
DR. SACCO: No.
DR. GOLDSTEIN: No.
DR. JUNG: No.
DR. FAHN: No.
272
DR. LENAERTS: No.
DR. WELCH: No.
DR. SMITH: No.
DR. JESTE: No.
DR. GREEN: No.
DR. KIEBURTZ: That is unanimous. There
is a subpart question. Is it possible to define a
maximum recommended number of monthly
doses of
MT100 to avoid the risk of tardive
dyskinesia? Is
there discussion on this, or is there
preparation
to vote?
Looks like we ready to vote. Dr. Green,
we will start at your end.
DR. JESTE: It is possible to define the
risk but not on the basis of the data
that are
already there since one can do a
longitudinal
prospective study and then define that.
DR. KIEBURTZ: Okay.
So the answer for
now is--
DR. BASTINGS: We mean on the basis of
existing data.
DR. GREEN: No.
DR. JESTE: No.
273
DR. SMITH: No.
DR. WELCH: No.
DR. LENAERTS: No.
DR. FAHN: No.
DR. JUNG: No.
DR. GOLDSTEIN:
No.
DR. SACCO: No.
DR. KOSKI: No.
DR. HUGHES: No.
DR. KIEBURTZ: I also vote no. That was
unanimous no's on the two parts of
Question 2.
See, that was easier.
Question 3; do you believe
that, based on
the existing data on medication-overuse
headache,
there is evidence that a proportion of
patients
prescribed MT100 will likely take a
number of
monthly doses higher than the
recommended amount?
Discussion on that question?
DR. GOLDSTEIN: The question again, the
first phrase there, is the existing data
on
medication-overuse headache. I think the data on
medication-overuse headache is different
than we
274
might think for patients who take more
than they
are supposed to take because it may not
lead to
medication-overuse headache.
I think, again, we can answer
the question
the way it is written, but I want to
find out
exactly what they had in mind because,
if the
question is, do you think there is a
proportion of
patients likely to take more than the
recommended
dose, that is a different question than
the first
phrase.
DR. KATZ: We were just trying to link it
to previous evidence of overuse of other
migraine
treatments. But yes; we are interested to know
whether or not you think people are
going to take
more than they are supposed to.
DR. KIEBURTZ: Right.
And not so much
linked to the character or anything
about what
causes medication overuse headache, just the
question of--is that clear?
DR. LENAERTS: It would be better stated
maybe, on medication-overuse in
headache.
DR. KIEBURTZ: Okay.
That is the intent
275
of the question. Discussion on that question? Is
it my turn to start?
Is there evidence that a
proportion of
patients are likely to take a number
higher than
recommended? Yes.
DR. HUGHES: Yes.
DR. KOSKI: Yes.
DR. SACCO: Yes
DR. GOLDSTEIN: Yes.
DR. JUNG: Yes.
DR. FAHN: Yes.
DR. LENAERTS: Yes.
DR. WELCH: Yes.
DR. SMITH: Yes.
DR. JESTE: Yes.
DR. GREEN: Yes.
DR. KIEBURTZ: Very good.
Thank you. So
it is unanimous that it is likely that
they will
take more than the number recommended.
So we are changing focus here
entirely no.
This one is a little bit trickier
question. All
currently approved acute treatments of
migraine are
276
indicated without restriction regarding
the
presence or absence of nausea at
baseline.
Given that patients may have
nausea at
some attacks and no nausea at others,
given that,
does an indication limited to the
subpopulation of
migraine patients with no nausea at
baseline
represent a clinically meaningful and
acceptable
indication?
Discussion on that? Dr. Green.
DR. GREEN: Well, given the fact that it
is so counter-intuitive, I really
believe that both
doctors and patients will erroneously
give the
wrong advice.
DR. KIEBURTZ: Dr. Koski.
DR. KOSKI: I think that patients do
intermittently have nausea at various
times
throughout the course of their
headache. I think,
because they are given a drug, they
wouldn't
exclusively use it in terms of the
periods when
they didn't have any nausea. So just even
accepting the data as it is, I think
there is a
problem with the way a patient would use
it.
277
DR. KIEBURTZ: Dr. Porter.
DR. PORTER: I agree.
I think that this
drug will be used in patients with or
without
nausea if it is marketed.
DR. WELCH: Nausea is such a variable. As
we
have heard, this drug will be used in people
with or without nausea without question.
DR. KIEBURTZ: Further discussion? Dr.
Green, how do you vote on the question;
is it a
clinically meaningful and acceptable
indication.
DR. GREEN: No.
DR. JESTE: I am not a migraine researcher
so I think I should just abstain from
answering
that question.
DR. KIEBURTZ: Fair enough.
DR. SMITH: I would do the same.
DR. KIEBURTZ: Abstain.
DR. WELCH: No.
DR. LENAERTS: No.
DR. FAHN: No.
DR. JUNG: No.
DR. GOLDSTEIN: No.
278
DR. SACCO: No.
DR. KOSKI: No.
DR. HUGHES: I abstain as well.
DR. KIEBURTZ: No.
So three abstentions, nine
no's as to
whether this is a clinically meaningful
and
acceptable indication. Any questions from your end
of the table? Okay.
The fifth question; In a new
clinical
study, if the sponsor shows prospectively
in a new
clinical study in migraine patients with
no nausea
at baseline a significant contribution
of
metoclopramide on sustained headache
relief of 5 to
10 percent--this harkens back to
Question 1--5 to
10 percent of patients, a proportion of
people--again, this is a proportion of
the enrolled
subjects who have this response which is
sustained
headache pain relief, so that is 5 to 10
percent of
the patients, no benefit at the two-hour
pain
research, no contribution of
metoclopramide at a
two-hour pain response, no contribution
of
metoclopramide on the relapse rate or
279
rescue-medication use in the two- to
24-hour
period--so, again, this is a 5 to 10
percent
benefit on the synthetic measure but not
a
significant impact on either of the
elements that
make up the synthetic measure--would the
demonstrated benefit outweigh the risks
related to
tardive dyskinesia?
This is, again, those effects
in a group
that was enrolled with no nausea at
baseline; would
this have demonstrated a benefit
outweighing the
risks related to tardive dyskinesia.
Discussion of this? Dr. Sacco.
DR. SACCO: Again, I think the only thing
I would add here, we have a significant
contribution. When it says no contribution in the
second and third bullet there, I am
assuming we are
saying no significant contribution, but,
again,
there may be a trend in those two, that
when you
add them up, you have a significant
contribution.
DR. KIEBURTZ: I would say that is an
appropriate clarification. Again, I think that we
should clarify that the risk of tardive
dyskinesia
280
is whatever in your heart you think that
is since
we don't have evidence in that
regard--heart, mind.
I am not trying to be flip about
it. It is what
your own best estimation is.
DR. GOLDSTEIN: Clarification. It seems
that this question is a compound of all
the other
questions. So we have answered, for each of these
components, in one way. I don't see what question
we are answering that is different than
what we
have already answered.
DR. KIEBURTZ: Okay.
But we are going to
answer it because that is our job.
DR. GOLDSTEIN: Okay.
DR. KATZ: We will just see if you are
being consistent when you answer this
one.
DR. FAHN: It is a different question.
DR. KATZ: It is a test.
DR. GOLDSTEIN: I just want to know, are
you trying to get--I want to answer the
question
that you are asking.
DR. KATZ: No, no; it puts everything
together. Then, of course, the thing we haven't
281
talked about is the very last
thing. But, no; you
are right.
DR. KIEBURTZ: Dr. Fahn.
DR. FAHN: I read this question as
different from the first question,
Question No. 1,
is that here we are saying on
contribution of
metoclopramide on relapse rate or rescue
medication
used in that two- to 24-hour period
which wasn't in
the previous question. So this is now saying, in
the long run, you are still going to
have to take
rescue medicine just as often, and so
forth. So,
to me, that changes the equation quite
differently.
It adds another element which the FDA
wants us to
answer and I think this now adds that
other element
we have to look at and think about.
DR. KIEBURTZ: There was not a
specification before about the no
significant
contribution on the relapse rate.
Dr. Porter.
DR. PORTER: My problem with this question
is that it assumes that this no nausea
at baseline
is, in fact, something that we really
believe the
282
company has shown. In my understanding, this is
pretty much a post hoc analysis. We are not
absolutely sure that they can reproduce
this.
I think that, to ask this
question assumes
that they are going to look for this
small
subpopulation which, in fact, might be a
mistake
because, if they are wrong on that, then
their drug
might be good for migraine as
whole. I think that
we ought to ask the question of
ourselves as well,
do we think that this is a subpopulation
that
company should consider as a population
that they
want to chase because it is a high-risk
event. It
cuts down the total number of patients
available,
et cetera.
I am not sure that we are
there yet.
DR. KATZ: This question just sort of took
as a given that if this was a real
reliably
identifiable or appropriate subgroup and
they
were--and the first part says, and they
were to
prospectively show it again, would all
of these
things apply.
I think you have already said
that you
283
don't think that the no nausea at
baseline is an
appropriate subgroup in which to develop
the drug.
I think that is more or less how I
interpreted the
last vote, or whichever one it was.
So I think this question does,
more or
less, incorporate several of the
questions you have
already voted on and it would seem as if
the answer
to this question would be obvious. I suppose we
could ask, if this is what you saw in
the entire
population; in other words, they did a
study both
with and without--you know, the typical
population,
as they have already done, and basically
saw the
same results that they have already seen
twice,
would it be acceptable.
But I think you have already
answered that
question as well. I think you have answered that
they have to show something in two
hours. Anyway,
I actually think it has already been
answered, but
if you want to vote on it, you can.
DR. KIEBURTZ: Dr. Temple, did you want to
say something?
DR. TEMPLE: Not to get into too much of
284
study design things, if the company
wanted to do
further studies to document and say and
an effect
at two hours and really thought that the
no-nausea
population was the right place, they
could still do
a study in the mixed population, make
the primary
endpoint the effect of the no-nausea
population and
get data on the other.
DR. KIEBURTZ: Absolutely agree.
DR. TEMPLE: That is all for later.
DR. WELCH: I guess it depends on what the
5 to 10 percent is. If it is used here as what do
you think would be a clinically
persuasive
difference, independent of what the data
has been
on
nausea, that is a different question that really
addresses the second question about
additional
data.
DR. KIEBURTZ: Just staying on the first
question, I think this is a pretty
straightforward
one to vote which I think the comments
to date, we
know what the answer is going to
be. It is
essentially a contribution with a new
feature about
specifying a nonsignificant contribution
of the
285
relapse period.
Is it my turn to start
first? Would the
demonstrated benefit outweigh the risks
related to
tardive dyskinesia. I would vote no.
DR. HUGHES: I vote no.
DR. KOSKI: No.
DR. SACCO: No.
DR. GOLDSTEIN: No.
DR. JUNG: No.
DR. FAHN: No.
DR. LENAERTS: No.
DR. WELCH: No.
DR. SMITH: No.
DR. JESTE: No.
DR. GREEN: No.
DR. KIEBURTZ: So unanimous on the no.
If not, I guess our response
was presaged
by considering if we said no, if we vote
no to that
first question, what additional data, or
desired
primary outcome measure, or desired
effect on
sustained relief, could provide evidence
of safety
and efficacy?
286
What I understand here is we
can go back
up to these bullet points--and now is an
opportunity for us, although I am
thinking we are
not going to take three hours of
opportunity to do
this, to flesh out some of the things we
have been
alluding to regarding whether two hours
is
important. I think we can comment here even about
the nausea or not.
So I think a question which
has already
been posed by Dr. Katz and Dr. Bastings
is whether
we would like to see a benefit of the
two-hour
response. Dr. Welch also mentioned a pain-free and
a sustained pain-free response. Maybe we can have
some discussion on this point.
Do you want to comment at all,
Dr. Welch,
not to pick on you.
DR. WELCH: I think that having said that
we accept that this combination of
medication could
be used for certain patients, that it
behooves us
to ask for the most rigorous endpoints
in any
clinical trial that we can. The most rigorous is a
two-hour pain-free sustained over 24
hours.
287
What patients really want is to be
pain-free as early as possible. That is really
what the patient ideal is. So, for that reason, I
would ask for that particular data given
that we do
accept that, with this risk in a limited
population, that this could go ahead.
DR. KIEBURTZ: Dr. Katz and Dr. Porter.
DR. KATZ: I just have a question because,
obviously, we have not adopted as
required for the
approval of the typical, if there is a
typical,
acute migraine treatment, the pain-free
at two
hours.
We have had mild or no pain. I
just want
to sort of flesh this out a little bit
more. Do
you think it should be pain free at two hours
specifically because of the potential
risk or do
you think that is sort of a generic
requirement?
DR. WELCH: I think it is ideal endpoint
that the community know us for, the
headache
community, the IHS regulations or
guidelines. That
is the first thing. But I think it is the most
rigorous endpoint that you can get and I
think,
because of the risk, that we deserve to
see the
288
most rigorous endpoint tested, if that
answers your
question.
DR. KATZ: Yes; it does.
DR. KIEBURTZ: Dr. Green.
DR. GREEN: I, like Dr. Welch, was
surprised that endpoint, the primary
endpoint, to
the study wasn't two-hour pain
something, anyway,
that certainly we would like to see
trials going
forward with the primary endpoint being,
hopefully,
two-hour pain free because, among other
things,
that probably even predicts recurrence
rates and
certainly, when we talked about drug
overuse, if
someone is pain free, they are very
unlikely to
redose.
DR. KIEBURTZ: So the two-hour time point
is an important one as assessment of
efficacy.
DR. GREEN: Right.
DR. KIEBURTZ: Of those, the pain-free
response is perhaps, even more
informative than the
pain response?
DR. GREEN: Actually, there is another
one.
There is migraine-free which is pain-free,
289
photophobia-free, phonophobia-free,
nausea-vomiting free, which is even a tougher
one.
DR. KIEBURTZ: You can escalate the
characteristics of what the two-hour
endpoint is
but that is an important time point at
which to
demonstrate the marginal benefit of--I
don't mean
marginal, small, but the additional
benefit of
metoclopramide over naproxen.
DR. GREEN: Definitely.
DR. KIEBURTZ: Dr. Fahn.
DR. FAHN: There are three conditions in
this area and one of them that we have
been talking
about is the two-hour one. But I would say if any
two of these would be sufficient in my
mind that
metoclopramide was superior to naproxen
alone; that
is, even if the two-hour wasn't any more
superior
pain-free than naproxen alone but they
got better
at the end of the day and they didn't
have any
relapses and they felt better, that
would be--those
two would be fine with me.
So that is what I would look
at. One
alone is probably not sufficient for the
risk but
290
two out of the three would be sufficient
for the
risk in my book.
DR. KIEBURTZ: So either--I am just trying
to think.
DR. FAHN: The relapse rate was one of the
risks.
The two-hour time point is another one of
the outcomes. The sustained headache relief.
DR. KIEBURTZ: I don't think you could get
the components without getting the
composite, but I
get your point. Two out of the three rather than
just one out of the three which is the
circumstance
now.
DR. SMITH: A little off the endpoint
question, but I would like to see that
combination
be better than a higher-dose naproxen is
one
question because you could increase the
dosage and
potentially have the same type of effect
for
naproxen alone. The other thing is how would it
work among people that failed naproxen
alone would
be another interesting question because,
again, you
are talking about a very unique risk and
so there
probably would be a drug that would not
be a
291
first-line so how does it work in people
that fail.
Would you see that same response?
DR. KIEBURTZ: So one is an issue of
comparators, not just to the naproxen
dose
intrinsic in MT100 but to a higher dose
as a
comparator.
DR. SMITH: Exactly.
DR. KIEBURTZ: The other question is one
of selection criteria in terms of people
who
failed.
DR. WELCH: A specific trial in naproxen
failures. It has been done for triptan failures.
Then you might just ease up a little bit
on the
rigor of your endpoint.
DR. TEMPLE: To do that trial right, you
have to randomize those people who, by
history or
failures, back to this product again and
naproxen.
So you are enriching it for naproxen
failures.
That design can work if the effect is
decent,
large.
DR. PORTER: I think you have to have a
little flexibility for the company. I think our
292
very rigid two hour must be pain-free
might be a
hurdle too high. I would urge you to think about a
little flexibility even though you want
to set the
standard high for a drug that is not as
safe as
some.
DR. WELCH: But the company doesn't want
to be set a lower standard if the
standard for the
whole headache specialty becomes that
rigorous.
DR. PORTER: How many drugs do you have
that meet that standard?
DR. KIEBURTZ: Let's just not get into a--
DR. PORTER: Okay.
DR. KIEBURTZ: Please.
Dr. Goldstein, you
had a comment?
DR. GOLDSTEIN: Yes.
The other point,
this compound question that I think
still needs to
be considered is is the addition of the
rescue
medication--the question is, if you are
taking care
of a patient again, that you want them
to be able
to take a drug and have relief, be able
to get back
with their work and not be having to take
additional drugs. If they require additional
293
drugs, I think that needs to be factored
into the
equation.
The second point is, as you
design a
trial, what the appropriate comparator
group is. I
guess the question that you have from
the
regulatory standpoint is the only
question that you
are really looking at, is whether the
metoclopramide component adds to the
naproxen but
now how the combination would compare
with other
approved agents.
DR. KATZ: That's the first question,
absolutely, is the combination policy of
both
components making a contribution. The question of
whether or not the actual product, how
that
compares to other products, is usually
not one that
we consider from a regulatory point of
view except
when you are worried that the product
might be more
dangerous than everything else that is
out there.
There have been
extraordinarily rare
occasions when you actually have to show
that your
product actually beats something else
out there in
order to get approved because it is so
dangerous.
294
So, yes; in some sense, we always think
about that
in the back of our minds but we almost
never
require it because it just doesn't--the
circumstances don't support it.
DR. KIEBURTZ: Dr. Sacco.
DR. SACCO: I just wanted to go back to
the endpoint question again. I am just trying to
understand why the migraine community is
basically
saying that outcome for clinical trials
regarding
migraine drugs should be changed. From my
understanding and what I have learned
today and
what I am reading is that pain research,
none,
pain-free, or mild pain has always been
the
endpoint.
Is it because we are hearing
the risk of
this drug or do you think, in general,
for every
migraine drug to come, the new endpoints
should be
pain-free. If so, I am just trying to understand
why, because I am okay with none or mild
pain, but
I am continuing to hear you want it
changed to be
pain-free.
Am I not reading that right?
295
DR. WELCH: The issue is how do you define
mild.
What is mild? It is very
subjective. So
the most rigorous one would be
pain-free. The
outcome from here on in, I believe, by
the
community would be to use that.
There are other endpoints that
you could
choose, but I would be afraid,
addressing the issue
for the company is, if someone else came
up with
another drug with a more rigorous
endpoint and they
were given a more flexible one,
that they wouldn't
compete well with it.
But I think if you certainly
do a trial
against naproxen, itself, in naproxen
failures, you
could let up on your endpoint, again
qualifying the
study.
DR. KIEBURTZ: Dr. Hughes, you had a
comment?
DR. HUGHES: I guess the main comment I
have is I would like to see the other
side of the
equation and get a bit more formal information
about the risk of TD in this
population. I would
hate to see an efficacy trial with
whatever
296
endpoint, or similar endpoints, as has
been done
with a 5 percent difference and still have
considerable uncertainty about the risks
of TD in
this population.
DR. KIEBURTZ: So addressing the issue of
what additional data, you would like
more safety
data.
DR. HUGHES: Formally obtained; yes.
DR. JESTE: I think there is an
opportunity to look at safety in a broad
perspective, not just tardive dyskinesia
but also
the various extrapyramidal symptoms,
Parkinsonism,
microdystonia, akathisia. This should be done.
There are number of examples in which
this has been
done using standardized rating scales
for each of
these on a regular basis and continuing
that for
six months to a year at the very least
because
really one cannot--100 patients keep on
the drug
for one month is not the same as 100
patient
months.
You really need patients to be treated for
one year before you can say anything
about the
incidence of tardive dyskinesia let
alone its
297
persistence.
So what I would strongly
recommend in
terms of suggested studies would be
longer-term
follow-up studies, standardized rating
scales for
Parkinsonianism, akathisia, dystonia and
tardive
dyskinesia.
DR. KIEBURTZ: Dr. Katz and then Dr.
Lenaerts.
DR. KATZ: Maybe a little discussion on
this point would be worthwhile because
these sort
of long-term large safety studies have
been done
when you are trying to sort of cap the
risk or
say--you might think about, well, I
think 0.1
percent risk might be acceptable given this
sort of
benefit on an appropriate outcome, so
you would
have to figure out how many people that
would be.
You may talk about thousands
of patients
followed for a year. I am just wondering whether
or not people, again, postulating this
sort of an
effect on an appropriate outcome,
whether or not
people think that that would be
something that
would be necessary, even if they were to
show
298
effectiveness at this level.
DR. JESTE: My feeling is that if we did
not suspect tardive dyskinesia with this
drug, then
I don't think one would ask for
longer-term
studies.
But here there are grounds to think that
the drug would be associated with some
risk of
tardive dyskinesia which we don't
know. It could
be minimal. But, still, there is clearly some
risk.
I think that it behooves on
us, then, to
have at least some long-term data
because some
patients will, indeed, be using the
drug. And the
findings may turn out, may show that,
actually, the
risk is very low, in which case it will
be helpful.
I do think that long-term studies will
be warranted
in a case like this.
DR. KIEBURTZ: Dr. Lenaerts.
DR. LENAERTS: Would the number needed to
treat shed light into this and, in that
case, is my
assumption right if we have, say, in 304
study,
rounded out 32 percent versus 28
percent, would it
be a number needed to treat of
eight? Would that
299
be correct? Would that be useful to look into
that?
DR. KIEBURTZ: I am not sure that that is
the right number.
DR. LENAERTS: That wouldn't apply?
DR. KIEBURTZ: For number needed to treat.
But, anyway. I am not sure.
DR. LENAERTS: I am just throwing in the
question.
DR. KIEBURTZ: Okay.
Dr. Porter, you had
a question?
DR. PORTER: Just a comment and that is if
the risk is, in fact, relatively low in
this 0.038
percent category, if you can have any
kind of power
at all to measure this, it is going to
take
thousands and thousands of patients, as
you already
mentioned, unless you are lucky, or
unlucky, and
you happen to stumble over one
early. But you
could do 2,000, 3,000, 4,000 patients
and still not
see it and it could still be there.
DR. KATZ: Right; you could decide up
front what sort of a risk you would be
willing to
300
live with. In other words, not greater than 0.1
percent.
DR. PORTER: What kind of power you
wanted.
DR. KATZ: Right; and then you just figure
out how many people. But, yes; we would have to
know what people thought would be an
acceptable
risk and then you work backwards and you
figure out
how many people you need to follow. But, yes; it
could be, depending on what sort of a
risk would be
acceptable, it would be thousands of
people. Sure.
I am trying to figure out
whether that is
something you think we ought to do and
pick a risk
to cap it at, or--
DR. WELCH: That would be extraordinarily
difficult and extraordinarily expensive
in the
migraine population. I think the real issue, that
what we are dealing with here, is that
if MT100
comes to acceptance and general
prescription, that
all of us know that, in a population of
migraine
patients, or chronic-headache patients,
whatever
that makes up, that they will be taking
this drug
301
on a chronic basis, a long-term
basis. It is very
difficult to actually reproduce, at any
clinical
trial, an interaction of someone who has
the
pathogenic factors of a chronic
headache, perhaps
with dopamine hypersensitivity and the
interaction
of using the drug.
So it is an almost impossible
thing to do,
I would think. But the issue is, given that we
know that there will be a subgroup of
patients who
will take this medication
inappropriately, that we
really must be sure that it is effective
for a
subgroup of patients who really need it.
Answering the very eloquent appeal for
pain relief in migraine, which is very
real because
migraine patients will, even if some of
them know
that they are at major risk for vascular
insult,
will take a triptan and take that
risk. We do know
that you can use metoclopramide and
Naprosyn
separately. In fact, before the triptans, I am old
enough here to be a pre-triptan-era
prescriber, it
was not uncommon for me to combine these
two
medications in patients that didn't
respond to
302
Naprosyn alone.
So the real reason why we must
ask for
extreme rigor, I think, with this particular
drug
is knowing that there will be a
population that may
overuse this drug with the risk of
tardive
dyskinesia. But to reproduce that in any clinical
trial, I would think it is just
impossible.
DR. KIEBURTZ: I would ask questions in a
slightly different direction because we
have not,
in this discussion, gone this way. Just say we
don't get more evidence about safety,
that we are
unable to better estimate with precision
then
something that we think is between 0.038
and 1.0.
Say we can't figure that out. Is there a magnitude
of benefit that is greater than this
number here,
since we voted no to this, that would
make people,
in that situation of relative ignorance,
change
that to a yes.
So, if there was a 20
percent--the
difference between the naproxen and
MT100 group was
20 percent--would that be enough to
overwhelm
whatever the concerns are about the
safety. I
303
think that is another question that we
are being
asked about. Or would, no matter what the
magnitude of the benefit, those safety concerns
would be persistent.
I don't see any clear thoughts
on that
one.
DR. FAHN: I would just go back to what we
talked about before that I feel to be
absolutely
safe, patients would have to show they
don't
respond at all to naproxen alone but now
would
respond to the combination drug if there
is a
combination drug on the market.
As Michael just said, that
before there
was a combination drug, you could still
prescribe
metoclopramide if you think it is going
to be
added.
You try naproxen alone and if it didn't
work, okay, we are going to try the two
together.
You will see. Then, if it doesn't work, then you
drop it.
If it does work, then there is a certain
risk that you tell the patient there is
going to be
and you can take this combination if you
are
willing to accept that risk.
304
I think that is the kind of
question I
would like to see directed if we were
going to look
for--in other words, it has to has some
restriction
on a combination drug that you wouldn't
have to
have if they were prescribed separately
because--normally, when they are
prescribed
separately, it is an extra step.
Too many doctors will say,
well, just take
this combination. It gives you both the advantages
of naproxen alone plus the
metoclopramide. I think
that makes the risk too dangerous.
DR. KIEBURTZ: So, to paraphrase, the
approach, rather than answering by a bigger
benefit or quantifying the risk, is
modifying the
path to which you get to that drug.
DR. FAHN: I think that is extremely
important how you give that path because
there
shouldn't be--if you are going to take
any risk,
you ought to make sure that risk is
worth taking
and, therefore, that you are getting
benefit that
you wouldn't have had otherwise.
For that particular person, if
they fall
305
within that 5 or 10 percent, 20 percent,
or
whatever number you want to give a
category, why,
for that person, they are getting a
great benefit
and they are willing to take that
risk. I think
that is okay.
DR. KIEBURTZ: Are you getting answers?
Is this discussion germane to the--
DR. KATZ: Yes.
There are a number of
ideas that we will have to think about
but I think
they are all relevant.
DR. KIEBURTZ: Okay.
This is not a voting
question because it is, what additional
data would
you like. So it is not a yes or no. We can't give
a yes or no here. Would someone like to make
additional comments? I see two.
Dr. Jeste.
DR. JESTE: Going back to safety, I am not
suggesting that we need to have huge
studies to
find out the incidence of tardive
dyskinesia. I
think one can use that normal
involuntary movement
scale as outcome for the safety purposes as major.
So what you are looking at is really
percent
increase in the M score. Say, the mean score,
306
let's say, goes up from 0.5 to 1.5. Those patients
will still not meet the criteria for
tardive
dyskinesia because you need a minimum
score of 2,
minimum at least 1. So that can be done in a few
hundred patients. So it is really not the number
of patients that is critical. It is the length of
the study that will be important. That can be done
in as many patients as are needed for
just looking
at outcome.
DR. KIEBURTZ: Dr. Goldstein.
DR. GOLDSTEIN: Again, just from a
clinical standpoint, I think the real
question is
whether the patient taking X medicine as
opposed to
Y is going to get on with their life
later, be able
to get back to their life sooner rather
than later.
If you just improve pain but
they are
still debilitated because of the
concomitant
symptoms, you haven't really done
much. So, as a
composite measure, I think it would be
good to have
some measure of migraine-related
disability, and I
know such scales exist, to be considered
as one of
the endpoints.
307
That is what we are really
trying to do
here.
The other thing to consider in terms of some
of these trade-off issues--I said it
before, but,
in terms of additional data, that data
can be
obtained so we are not sort of guessing
these
things.
We can get finite data to support what
risk people with migraine would be
willing to take
of having these sequelae to be pain-free
or without
disability at whatever given high
proportion.
So, again, I think that those
data would
be very helpful to inform both the
company's
decisions as to how to go and for the
FDA as well.
DR. KIEBURTZ: To summarize Question 5, on
the first part of it, we voted no
uniformly on the
way it was categorized and then discussed
ways
where data might be helpful in
addressing the
question. One is more safety data. Two is the
two-hour endpoint seems to be important
as to
whether that needs to be something
beyond the
traditional pain response is something
that is
debated and, also, we talked about ways
in which
subjects or patients might access the
medication
308
through specific failure of other
interventions
prior to exposure to this intervention.
I am going to briefly
summarize our
discussion. Unfortunately, your chair has failed
my two-hour response to my migraine
intervention so
my thinking is a little cloudy. So you will have
to bear with me. In addition to Dr. McCormick,
there are other people who have trouble
responding
to their migraine medications.
We concluded that the current
estimate of
tardive dyskinesia following exposure to
metoclopramide, particularly in this
setting, is
not a reasonable estimate. We talked some more
about how we might get some better
estimates of
that.
Both in the initial question
and the
second question, that the amount of
benefit
demonstrated so far, without saying
whether that is
significant or not, is not sufficient
given the
perceived risk in the absence of
concrete data, the
perceived risk given the absence of
benefit at
two-hour endpoints.
309
We don't think that there is
enough
evidence that there is no risk of
tardive
dyskinesia with chronic intermittent
administration
nor can we identify a dose that would be
below the
risk, a number of doses that would
confer no risk.
We think it is likely that, no matter
how the drug
is labeled and approved, that people
will take it
more than whatever the recommended
dosage is if
there is a limitation on the number of
dosages, and
did not have support for the idea of
individuals
with nausea at baseline being an identifiable
group
of a clinically meaningful and
acceptable
indication for the treatment of
migraine.
I think that summarizes our
discussion.
DR. PORTER: Could I just add one comment.
I think there is an uncertainty about
whether or
not the nausea or no-nausea populations
have been
demonstrated here. The company should not mislead
itself by a subgroup analysis post hoc
that
necessarily takes them down the wrong
path.
DR. KIEBURTZ: I think, then, unless there
are some comments from Dr. Katz.
310
DR. KATZ: No. I
just want to thank
everybody. I think it is particularly difficult to
discuss these matters and come up with
decisions
and advice based on so little data, at
least on
parts of this. So I really appreciate it.
Also, I just learned that
Anuja, this is
her last meeting with the
committee. So I want to
thank her publicly for all her
work. And good luck
in the future. We are sorry to see you go.
DR. KIEBURTZ: You keep your secrets well,
like everyone else here at this
agency. Thanks to
the committee members for coming, for
staying on
point, to the sponsor for their
presentations and
their responsiveness to our questions.
We will adjourn the meeting
now.
(Whereupon, at 2:40 p.m., the
meeting was
adjourned.)
- - -