DALLAS, Nov. 15 /PRNewswire-FirstCall/ -- Pfizer Inc's smoking
cessation medicine varenicline tartrate was shown to be more effective
than the only marketed oral prescription anti-smoking medicine,
according to data presented here today at the annual meeting of the
American Heart Association. Upon approval, Pfizer intends to market
varenicline under the brand name Champix(R).

Discovered and developed by Pfizer, varenicline is a selective
nicotinic acetylcholine receptor partial agonist, the first in a new
class of potential smoking cessation therapies.

In two double-blind placebo-controlled studies involving about 2,000
smokers, patients received either varenicline (1 mg twice daily),
bupropion, marketed as Zyban (150 mg twice daily), or placebo for 12
weeks. Patients were followed for an additional 40 weeks without
treatment.

In both studies, 44 percent of varenicline-treated patients quit by
the end of the 12-week treatment period, significantly more than the
30 percent of Zyban patients who quit. Among patients who received
placebo, 18 percent had quit by the end of the 12-week treatment
period. The odds of quitting smoking for patients taking varenicline
were approximately two times higher than those on bupropion, and four
times higher than those on placebo.

After one year, patients who received varenicline were significantly
more likely to remain smoke-free compared to patients who received
bupropion or placebo.

"These results are very encouraging," said Dr. Serena Tonstad, head
physician, Department of Preventive Cardiology, Ulleval University
Hospital, Norway. "Smoking doubles a person's risk of cardiovascular
disease and triples the risk of death from heart attack. Patients who
are serious about quitting should seek medical support and treatment
to help them ultimately succeed."

A third study randomized smokers who successfully quit smoking after
12 weeks of varenicline to 12 weeks of either placebo or an additional
12 weeks of varenicline. These patients were followed for 28 weeks
after the treatment period.

There were significant benefits observed among patients who received
additional treatment after successfully quitting on varenicline.
Seventy-one percent of patients who received the additional course of
varenicline remained abstinent after six months, compared to 50
percent who received placebo as the second course.

Smoking is the leading preventable cause of illness and premature
death in the United States. Each year, smoking is responsible for
140,000 deaths from cardiovascular disease by increasing the risk of
heart attack, stroke and sudden death. Annual health-related costs in
the United States are estimated to be $167 billion.

Smoking is a chronic relapsing condition that involves a physical and
psychological addiction to nicotine. When a smoker inhales a
cigarette, nicotine reaches the brain in less than 10 seconds. The
nicotine binds to receptors, leading to the release of dopamine in the
pleasure centers of the brain. As nicotine levels drop, satisfaction
recedes quickly, resulting in craving and withdrawal symptoms such as
irritability and anxiety. This, in turn, leads to continued smoking
behavior.

"Varenicline was specifically designed to work at the same receptor
site as nicotine to relieve craving and withdrawal symptoms while at
the same time blocking the reinforcing effects of nicotine," said Dr.
Salomon Azoulay, varenicline development lead at Pfizer.

In all trials, varenicline was well tolerated, with overall
discontinuation rates similar to placebo. The most common side effects
included nausea, headache, trouble sleeping and abnormal dreams.

This month Pfizer submitted a New Drug Application to the FDA for
varenicline as well as European registration for smoking cessation.

DISCLOSURE NOTICE: The information contained in this release is as of
November 15, 2005. 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 a product
candidate which is under regulatory review in the United States and
Europe that involves substantial risks and uncertainties. Such risks
and uncertainties include, among other things, whether and when such
regulatory authorities will approve the product candidate, their
decisions regarding labeling and other matters that could affect its
commercial potential as well as 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, 2004 and in its reports on Form 10-Q and Form 8-K.

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