Smokers taking Pfizer's varenicline doubled their chances of quitting compared to those taking GSK's Zyban (buproprion), according to results of two Phase III studies presented at the American Heart Association annual meeting in Dallas.

In the two identical double-blind studies, about 2000 smokers were randomised to 12 weeks' treatment with varenicline, Zyban or placebo. Quit rates were 44% in the varenicline group compared with 30% in the Zyban group and nearly 18% in the placebo group-which meant that, compared to placebo, varenicline quadrupled the odds that smokers would quit.

Varenicline is a selective nicotine acetylcholine receptor partial agonist – SNARPA - and relieves craving and withdrawal symptoms, while diminishing the rewards of smoking. It is the first non-nicotinic drug specifically developed for use in smoking cessation.

Marketing applications were submitted for varenicline in Europe and the USA earlier in November.

Source: Sue Lyon at the AHA in Dallas.