Objectives: To evaluate varenicline's efficacy for smoking cessation versus bupropion SR and placebo and to explore whether factors typically predictive of abstinence influence varenicline's efficacy versus placebo, as measured by the week 9-12 continuous abstinence rate (CAR9-12).
Methods: Smokers in 2 randomized, placebo-controlled trials received varenicline 1 mg BID (n=696), bupropion SR 150 mg BID (n=671), or placebo (n=685) for 12 weeks. Nontreatment followup lasted 40 weeks.
Results: CAR(9-12) was greater for varenicline (44.0%) versus bupropion SR (29.7%; P<0.0001) and placebo (17.7%; P<0.0001). CAR(9-12) for varenicline versus placebo was not affected by age, gender, or nicotine dependence level.
Conclusions: Varenicline was more efficacious than bupropion SR or placebo. Varenicline's efficacy versus placebo was not influenced by factors predictive of abstinence.
Trial registration: ClinicalTrials.gov NCT00141206 NCT00143364.