The
U.S. Food and Drug Administration (FDA) and the European Agency for the Evaluation
of Medicinal Products (EMEA) will soon review applications for accelerated approval
of the novel anti-HIV drug maraviroc,
according to an announcement this week by Pfizer.
FDA
and EMEA grant accelerated approval reviews to experimental therapies that have
demonstrated potentially significant improvements over medications
currently on the market.
If
approved by the European and American regulatory agencies as expected, maraviroc
will become the first member of the CCR5 antagonist drug class to win approval.
The CCR5 antagonists have a unique mechanism of action against HIV that works
by blocking entry of the virus into as yet uninfected cells. All currently
available anti-HIV drugs (except for T-20 or Fuzeon) interfere with the replication
of HIV inside cells that are already infected with the virus.
"There
is a profound global need for new medicines to help HIV/AIDS patients," said
John LaMattina, President of Pfizer Global Research and Development. "We
expect that CCR5 antagonists like maraviroc will become critically important new
treatment options for patients who are resistant or intolerant to their current
HIV/AIDS therapies."
The
U.S. FDA Antiviral Drugs Advisory Committee will conduct its priority review of
maraviroc at an open public hearing 8 AM to 4 PM on Tuesday,
April 24, 2007. The review will take place at the FDA, Center for Drug Evaluation
and Research Advisory Committee Conference Room, Rooom 1066, 5630 Fishers Lane,
Rockville, MD.
Maraviroc
Development Background
The
discovery of maraviroc dates back to 1997, when Pfizer research scientists in
Sandwich, UK, designed the molecule following the publication of 2 significant
research findings.
A
study published in 1996 described resistance to HIV-1 infection in certain Caucasian
subjects, and the same year, another journal reported the binding of HIV to the
CCR5 receptor. Scientists noted that about 1% percent of Europeans who lacked
genes for CCR5 receptors were the very ones who were resistant to acquiring HIV
infection.
This
finding suggested that blocking the virus's entry through this gateway may lead
to a breakthrough therapy. Based on these emerging scientific insights and patient
need, the maraviroc team significantly accelerated development.
"Maraviroc
is an outstanding example of rapid development and continuous innovation through
which Pfizer researchers quickly translated a scientific hypothesis into a promising
compound in this area of great medical need," said Dr. Ethan Weiner, Senior
Vice President, Pfizer Global Research and Development.
Pivotal
Trials
The
marketing applications for maraviroc follow Pfizer's review of efficacy and safety
data from 2 pivotal Phase III trials. The trials, MOTIVATE-1 and MOTIVATE-2 (Maraviroc
plus Optimized Therapy In Viremic Antiretroviral Treatment-Experienced patients),
provided 24-week data comparing optimized background therapy, with or without
maraviroc, in over 1000 highly treatment-experienced patients with CCR5-tropic
HIV-1.
These
study results have been accepted for presentation at an important upcoming scientific
conference in the U.S.
In
addition, the independent Data Safety Monitoring Board (DSMB) for maraviroc met
on January 15, 2007 and continues to monitor the ongoing clinical program. The
DSMB recommended that the maraviroc Phase III registration trials, in both treatment-naive
and treatment-experienced patients should continue as currently designed.
Update
on Maraviroc Expanded Access Program
In
December 2006, Pfizer announced plans to establish a multinational Expanded
Access Program to provide maraviroc to patients with limited available treatment
options based on its safety and efficacy observed in clinical trials to date.
The program is now open for enrollment, with a target to enroll patients from
over 30 countries.
Maraviroc
Articles Posted on HIV and Hepatitis.com
Excerpts
from the Notice of the FDA Antiviral Drugs Advisory Committee Meeting to Review
Maraviroc
The
general function of the Committee is to provide advice and recommendations to
the agency on FDA's regulatory issues. The meeting will be held on April 24, 2007,
from 8 a.m. to 4 p.m. at the Food and Drug Administration, Center for Drug Evaluation
and Research Advisory Committee Conference Room, rm. 1066, 5630 Fishers Lane,
Rockville, MD.
Agenda:
The committee will discuss new drug application (NDA) 022-128, maraviroc 300 milligram
tablets, Pfizer, Inc., proposed for the treatment of antiretroviral-experienced
patients with chemokine (c-c motif) receptor 5 (CCR5)-tropic human immunodeficiency
virus (HIV).
Contact
Person: Cicely Reese, Center for Drug Evaluation and Research (HFD-21), Food
and Drug Administration, 5600 Fishers Lane (for express delivery, 5630 Fishers
Lane, rm. 1093) Rockville, MD 20857, 301-827-7001, FAX: 301-827-6776, e-mail:
cicely.reese@fda.hhs.gov, or FDA
Advisory Committee Information Line, 1-800-741-8138 (301-443-0572 in the Washington,
DC area), code 3014512531. Please call the Information Line for up-to-date information
on this meeting.
FDA intends to make background material available to
the public no later than 1 business day before the meeting. If FDA is unable to
post the background material on its Web site prior to the meeting, the background
material will be made publicly available at the location of the advisory committee
meeting and the background material will be posted on FDA's Web site after the
meeting.
Background
material is available at http://www.fda.gov,
and scroll down to the appropriate advisory committee link.
Procedure:
Interested persons may present data, information, or views, orally or in writing,
on issues pending before the committee. Written submissions may be made to the
contact person on or before April 3, 2007.
Oral
presentations from the public will be scheduled between approximately 1 p.m. and
2 p.m. Those desiring to make formal oral presentations should notify the contact
person and submit a brief statement of the general nature of the evidence or arguments
they wish to present, the names and addresses of proposed participants, and an
indication of the approximate time requested to make their presentation on or
before March 26, 2007.
Time
allotted for each presentation may be limited. If the number of registrants requesting
to speak is greater than can be reasonably accommodated during the scheduled open
public hearing session, FDA may conduct a lottery to determine the speakers for
the scheduled open public hearing session. The contact person will notify interested
persons regarding their request to speak by March 27, 2007.
02/16/07
Sources
Pfizer
Inc. Pfizer's Maraviroc to Receive Accelerated Regulatory Reviews in the US and
Europe. Press Release. February 13, 2007.
Food
and Drug Administration: Antiviral Drugs Advisory Committee. Notice of Meeting,
Federal Register Volume 72, Number 25, February 7, 2007. Department of Health
and Human Services.
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