Champix’s approval in Japan was based on a 12-week, randomized, double-blind, placebo-controlled study in Japanese smokers who wanted to quit smoking. The primary endpoint, the percentage of subjects who did not smoke at all during the four consecutive weeks between Week 9 and Week 12 was 65.4% (85/130 cases) in the Champix 1mg twice-daily group and 39.5% (51/129 cases) in the placebo group, a statistically significant difference between the two groups.
Champix reduces withdrawal symptoms and tobacco craving associated with smoking cessation by acting on the same receptor in the brain as nicotine but with higher affinity. Champix partially stimulates the receptor and triggers a reduced dopamine response, which helps to relieve the craving and withdrawal symptoms associated with stopping smoking.
Jeff Kindler, chairman and CEO of Pfizer, said: “Pfizer is delighted to be able to provide patients and physicians in Japan with Champix, a breakthrough medicine for smoking cessation that has helped millions of smokers who want to quit.”