Food and Drug Administration
Center for Drug Evaluation and Research
SUMMARY MINUTES OF THE CDER
ANTIVIRAL DRUGS ADVISORY
COMMITTEE
Members Present
(Voting)
Janet Englund, M.D. (Chair)
Maribel
Rodriguez-Torres, M.D.
Victor
DeGruttola, Sc.D.
Lauren Wood, M.D.
Kenneth Sherman, M.D., Ph.D.
Ronald Washburn, M.D.
John Gerber, M.D.
Robert Munk, Ph.D. (Consumer Representative)
FDA Participants
Mark Goldberger,
M.D., M.P.H.
Debra Birnkrant,
M.D.
Rosemary Johann-Liang, M.D.
Andrea James,
M.D.
Executive Secretary
Anuja M.
Patel, M.P.H.
Members Present (Non-voting)
Douglas Fish, M.D.
Richard Haubrich, M.D.
Consultants to the Antiviral Drugs Advisory
Committee (Voting)
Robert Grant, M.D., M.P.H
Veronica Miller, Ph.D.
Frank Maldarelli, M.D., Ph.D
Gene Morse, Pharm.D., FCCP, BCPS
Edmund Capparelli, Pharm.D.
Stephen Hall, Ph.D.
Consultants to the Antiviral
Drugs Advisory Committee (Non-voting)
Princy Kumar, M.D.
Antiviral Drugs Advisory
Committee Patient Representative (Non-voting)
Lynda Dee, J.D.
Antiviral Drugs Advisory
Committee Industry Representative (Non-voting)
There was no Industry Representative at this meeting.
These summary minutes for the
I certify that I attended the
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Anuja Patel, M.P.H. Janet Englund, M.D.
Executive Secretary Chair
Open Public Hearing Speaker
Mr. Rob Camp
Treatment Action
Group
·
Introduction Burkhard
Blank, M.D.
Senior Vice President Medicine/DRA
·
Tipranavir Development Douglas Mayers, M.D.
International Head, Therapeutic
Area Virology
·
Efficacy and Drug: Scott McCallister, M.D.
Drug
Interactions Global
Medical Team Leader, TPV
·
Safety Christopher
Corsico, M.D.
Head, Drug Surveillance and
Information
·
Resistance Douglas
Mayers, M.D.
International
Head, Therapeutic Area Virology
·
Potential Utility of Tipranavir Daniel Kuritzkes, M.D.
In Current Clinical Practice Director of AIDS Research,
Brigham
and Women’s Hospital,
Division
of AIDS,
Associate Professor of Medicine,
·
Conclusions Burkhard
Blank, M.D.
Senior Vice
President Medicine/DRA
·
Efficacy Evaluation Rafia Bhore, Ph.D.
Statistical
Reviewer
·
Resistance Evaluation Lisa Naeger, Ph.D.
Senior Microbiology Reviewer
·
Exposure-Response Data Jenny J. Zheng, Ph.D.
Pharmacometrics Reviewer
·
Drug Interactions Yuanchao (Derek) Zhang, Ph.D.
Clinical Pharmacology and
Biopharmaceutics Reviewer
·
Safety Profile and Conclusions Andrea James, M.D.
Medical Reviewer
Questions to the Committee:
Question 1:
·
Do the data demonstrate that
tipranavir/ritonavir (TPV/r) is safe and effective for the multi-drug resistant
HIV-1 infected population?
•
If no, what additional data are needed to provide
evidence of safety and efficacy?
Members that voted “no” felt that
additional data providing evidence of safety and efficacy was needed. Data
including long term efficacy data, drug interaction, and liver toxicity data
were among the suggestions. Substantial concerns regarding hepatic toxicity in
this patient population were raised by committee members. Overall the committee advised the Agency that
additional long- term follow-up was needed, specifically, in the female
population.
•
If yes, please address the appropriate population for
TPV/r use considering the following:
–
limited inclusion criteria of the RESIST trials
–
drug-drug interactions
–
resistance information and patterns associated with
optimal use
–
safety considerations
Members who voted “yes” felt that the need for the drug in this patient
population was great; however, members expressed concerns with need for long
term follow-up and toxicity management by specialists. Members urged the
sponsor and the agency to explore drug-drug interactions, including
interactions with lipid lowering agents, contraceptives, and cardiac drugs. The
committee suggested that future studies include women with rash, liver failure
patients, and toxicology.
Please see transcript for additional details
Question 2:
·
Given the data on transaminase elevations,
please provide your recommendations for:
•
TPV/r use in patients with underlying liver disease
•
Monitoring and management of hepatotoxicity during
clinical use
•
Future studies
Close follow up of patients receiving this therapy and long-term follow
up in enrolled study patients for hepatic toxicity were suggested. Specific suggestions for future studies
included the evaluation of more Hep B/C + patients and those entering treatment
with slightly higher LFT’s (such as grade 2).
The hepatologists on the panel were concerned that no liver biopsy data
was available and strongly recommended that such studies be considered in the
future. Because the correlation of
fibrosis and transaminase elevation is not perfect, concerns were expressed
about the increased risk for disease in those patients with fibrosis already
present.
Question 3:
·
The limited amount of data in females with HIV
infection in the TPV program shows an increased incidence of rash in
females. Please provide your
recommendations for:
–
Investigation of this safety signal in future studies
with TPV
The committee was concerned about an
insufficient amount of data in women in pivotal clinical trials,
particularly when the signal of skin rash was noted early. Recommendations for further studies with
women and diverse contraceptive methods were recommended.
Question 4:
·
Current information indicates the net effect of
TPV/r on substrates of CYP1A2, CYP2C9, CYP2C19 and CYP2D6 is not known, and
there are competing effects of TPV/r on CYP3A (inhibition) and P-glycoprotein
(induction). Please comment on
additional post-marketing drug interaction studies.
The committee suggested post-marketing
drug interactions studies using cocktail studies to evaluate mechanisms of
inhibition and induction. These studies
should evaluate the impact of TPV/r on various transporter systems including
PGP as well as MRP’s. Specific
interactions using digoxin, proton pump inhibitors, dual PI’s, calcineurin
inhibitors, and statins were recommended.
Other panel members recommended studies of phenytoin, midazolam, and
tenofovir as common agents in use in these patients.
Question 5:
·
Given the high inter-patient variability in TPV
exposures following fixed doses and exposure (blood levels)-virologic response
relationships, could a biomarker such as Cmin/IC50 be used for the
individualization of TPV/r therapy?
Please discuss the studies that would supplement the data presented
today.
Although the committee was very interested in the possibility of
therapeutic drug monitoring for the individualization of patient care with
potentially toxic drugs, the committee as a whole felt there was not enough
data to recommend this at the current time.
See transcript for additional details
Question 6
·
Please provide your recommendations regarding
the display of TPV/r resistance data/analyses in the TPV package insert that
would be useful to clinicians.
Simple but complete representation of available data was discussed,
with several specific designs suggested.
Recommendations for serial evaluation of hepatic function were also
discussed.
Question 7:
·
Please discuss and recommend future study
designs /data acquisition for the heavily pretreated population.
The Committee suggested incorporating
real time phenotypes in future studies and exploring possible mutations in the
patient population. Incorporation of at least two novel PI’s in treatment
studies was recommended, with potential studies evaluating two or more
investigational agents (including those from different manufacturers)were also
encouraged. Although collecting better
data on clinical endpoints was highly encouraged and such data was felt to be
useful, it was acknowledged that studies using surrogate markers will be
necessary in evaluating salvage studies in this patient population. Study designs including open label drug and
rollover to experimental arms after relatively short periods may be necessary
for practical and ethical reasons.
Following the
discussion session, the meeting adjourned at approximately