Inhibits A Sense Of Satisfaction Associated With Smoking AndRelieves Tobacco Craving

Business Editors/Health/Medical Writers

TOKYO--(BUSINESS WIRE)--April 22, 2008--Pfizer Inc announced todaythat on May 8, 2008, it will launch Champix(R) Tablet 0.5mg/1mg(varenicline tartrate), a novel smoking cessation aid for smokers withnicotine dependence in Japan, which has one of the highest rates ofsmoking among developed nations.

Champix was developed as the first non-nicotine drug designed forsmoking cessation in the United States and will be the first oralsmoking cessation aid available in Japan. The currently availablesmoking cessation aids such as 'Nicotine Replacement Therapy' (NRT)relieve withdrawal symptoms associated with smoking cessation byreplacing tobacco use through delivering nicotine. In contrast,Champix brings about a smoking cessation effect through a newmechanism of action which works by selectively targeting thealpha4beta2 nicotine receptors in the brain to reduce both craving andwithdrawal symptoms and reduce the pleasure associated with smoking.

Champix reduces withdrawal symptoms and tobacco craving associatedwith smoking cessation by acting on the same receptor in the brain asnicotine (the alpha4beta2 nicotine receptor) but with higher affinity.

 
Champix partially stimulates the receptor and triggers a reduceddopamine response, which helps to relieve the craving and withdrawalsymptoms associated with stopping smoking. At the same time, Champixprevents nicotine from binding at the receptor, so if a smoker slipsand smokes a cigarette, Champix reduces the reward and sense ofpleasure associated with smoking.

 
"Pfizer is delighted to be able to provide patients and physiciansin Japan with Champix, a breakthrough medicine for smoking cessationthat has helped millions of smokers who want to quit," said JeffKindler, chairman and chief executive officer of Pfizer. "Furthermore,we are gratified that health authorities in Japan recognize thebenefits of therapies such as Champix that address a major unmetmedical need."Champix's approval in Japan was based on a 12-week, randomized,double-blind, placebo-controlled study in Japanese smokers who wantedto quit smoking. The primary endpoint, the percentage of subjects whodid not smoke at all during the four consecutive weeks between Week 9and Week 12 was 65.4 percent (85/130 cases) in the Champix 1mgtwice-daily group and 39.5 percent (51/129 cases) in the placebogroup, a statistically significant difference between the two groups.