Pfizer And Medivation Initiate Phase 3 Trial Of Dimebon In Patients With Huntington Disease

U.S. Orphan Drug Designation Granted for Dimebon for Treatment of Huntington
Disease
NEW YORK & SAN FRANCISCO--(Business Wire)--
Pfizer Inc (NYSE: PFE) and Medivation, Inc. (NASDAQ: MDVN) today announced the
initiation of a Phase 3 trial of the investigational drug dimebon
(latrepirdine)* in patients with Huntington disease. The international safety
and efficacy trial, known as HORIZON, is designed to evaluate the potential
benefits of dimebon on cognition (thinking and memory) in patients with
Huntington disease. The companies also announced that the U.S. Food and Drug
Administration (FDA) has granted orphan drug designation to dimebon for the
treatment of Huntington disease.

"Based on the promising results of our Phase 2 trial of dimebon in Huntington
disease, we are pleased to advance dimebon into late-stage clinical
development," said Lynn Seely, M.D., chief medical officer for Medivation.
"Huntington disease is a fatal genetic disease for which no medications are
currently approved by the FDA to treat the cognitive impairment associated with
the condition."

Orphan status is granted by the FDA to promote the development of products that
demonstrate promise for the treatment of rare diseases affecting fewer than
200,000 Americans annually, such as Huntington disease, which affects 30,000
individuals in the United States, with another 150,000 at risk. Orphan drug
designation entitles Pfizer and Medivation to a seven-year period of marketing
exclusivity in the United States for dimebon if it is approved by the FDA for
the treatment of Huntington disease. It also enables the companies to apply for
research funding, tax credits for certain research expenses, and a waiver from
the FDA's application user fee.

*Latrepirdine is the proposed generic (nonproprietary) name for dimebon.

Design of the HORIZON Study

The double-blind, placebo-controlled Phase 3 trial will enroll approximately 350
patients with Huntington disease at approximately 50 sites in North America,
Europe and Australia. Patients will be randomized to receive either dimebon
(latrepirdine) 20 mg three times daily or placebo for six months.

The primary endpoints of the trial are the Mini Mental State Examination (MMSE),
which measures cognition, and the Clinician`s Interview-Based Impression of
Change, plus caregiver input (CIBIC-plus), which measures global function. The
trial will include only patients who have cognitive impairment, as subjectively
assessed by an investigator and objectively by MMSE score.

Secondary endpoints include the Neuropsychiatric Inventory (NPI), which measures
behavior; the Alzheimer`s Disease Cooperative Study - Activities of Daily Living
(ADCS-ADL), which measures self-care and daily function; and the Unified
Huntington Disease Rating Scale (UHDRS`99) Total Motor Score, which measures
motor impairment; and safety.

The trial is being conducted in collaboration with the Huntington Study Group
(HSG) and the European Huntington`s Disease Network (EHDN). The HSG is a
non-profit group of experienced clinical trial investigators from medical
centers in the United States and abroad dedicated to clinical research of
Huntington disease. The EHDN is a non-profit network of professionals providing
an infrastructure for large scale Huntington disease clinical trials throughout
Europe.

For more information about the HORIZON study, please visit www.horizontrial.com
or call 800-487-7671 or +49 731 5006 3103.

About Dimebon

Dimebon (latrepirdine) is an investigational drug in Phase 3 development for the
treatment of Alzheimer's disease (AD) and Huntington disease (HD). In
preclinical studies, dimebon has been shown to protect brain cells from damage
and enhance brain cell survival, potentially by stabilizing and improving
mitochondrial function. The dimebon mechanism is distinct from currently
available AD and HD medications.

About Huntington Disease

Huntington disease is a rare, neurodegenerative disease that is caused by the
death of specific brain cells. The genetic disorder is characterized by the
gradual development of involuntary muscle movements, cognitive impairment and
severe behavioral disturbances. No medications are currently approved to treat
the cognitive impairment (thinking and memory) of Huntington disease.

About the Pfizer/Medivation Dimebon Collaboration

Medivation and Pfizer have a global collaboration to develop and commercialize
dimebon for the treatment of Alzheimer's disease and Huntington disease. Under
the terms of the agreement, the companies are working in partnership to seek FDA
approval for dimebon and bring it to market in the United States. In addition,
following FDA approval, Medivation will co-promote dimebon to specialty
physicians in the U.S. Pfizer has responsibility for development, regulatory and
commercialization outside of the U.S.

For more information about Pfizer, visit www.Pfizer.com.

For more information about Medivation, visit www.Medivation.com.

Forward-Looking Statements

PFIZER DISCLOSURE NOTICE: The information contained in this release is as of
July 30, 2009. Pfizer assumes no obligation to update any forward-looking
statements contained in this release as the result of new information or future
events or developments.

This release contains forward-looking information about certain potential
indications for dimebon, including their potential benefits, that involves
substantial risks and uncertainties. Such risks and uncertainties include, among
other things, the uncertainties inherent in research and development; decisions
by regulatory authorities regarding whether and when to approve any new drug
applications that may be filed for such indications as well as their decisions
regarding labeling and other matters that could affect the availability or
commercial potential of any such indications; and competitive developments.

A further list and description of risks and uncertainties can be found in
Pfizer's Annual Report on Form 10-K for the fiscal year ended December 31, 2008,
and in its reports on Form 10-Q and Form 8-K.

MEDIVATION DISCLOSURE NOTICE: This press release contains forward-looking
statements, including statements regarding potential clinical indications for
dimebon, which are made pursuant to the safe harbor provisions of the Private
Securities Litigation Reform Act of 1995. Any statements contained in this press
release that are not statements of historical fact may be deemed to be
forward-looking statements. Forward-looking statements involve risks and
uncertainties that could cause Medivation's actual results to differ
significantly from those projected, including, without limitation, risks related
to progress, timing and results of Medivation's clinical trials, difficulties or
delays in obtaining regulatory approval, enrollment of patients in Medivation's
clinical trials, partnering of Medivation's product candidates, manufacturing of
Medivation's product candidates, competition with Medivation's product
candidates should they receive marketing approval, the adequacy of Medivation's
financial resources, unanticipated expenditures or liabilities, intellectual
property matters, and other risks detailed in Medivation's filings with the
Securities and Exchange Commission, including its quarterly report on Form 10-Q
for the quarter ended March 31, 2009 filed on May 11, 2009, with the SEC. You
are cautioned not to place undue reliance on the forward-looking statements,
which speak only as of the date of this release. Medivation disclaims any
obligation or undertaking to update or revise any forward-looking statements
contained in this press release.

Pfizer Inc
Media:
Sally Beatty, 212-733-6566
or
Investors:
Jennifer Davis, 212-733-0717
or
Medivation, Inc.
Patrick Machado, CFO, 415-829-4101

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