Pfizer Inc. (NYSE: PFE) announced today the completion of a double-blind, placebo-controlled, randomized clinical trial designed to assess the efficacy and safety of CHANTIX ®/CHAMPIX ® (varenicline) 1 mg BID in comparison to placebo for smoking cessation in patients with a past or present diagnosis of Major Depressive Disorder (MDD). The study met its primary and secondary efficacy endpoints. Subjects in the varenicline group had a higher likelihood of quitting at week 12 (primary endpoint) and at week 52 (key secondary endpoint). In addition, psychiatric scales included for safety assessments did not show a difference between varenicline and placebo.
“The results from this study offer important information which contributes to a further understanding of the clinical profile of CHANTIX/CHAMPIX,” said Steven J. Romano, M.D., senior vice president, head, Medicines Development Group, Global Primary Care Business Unit, Pfizer Inc.
The currently approved CHANTIX®/CHAMPIX® (varenicline) labeling states that the safety and efficacy of varenicline in patients with serious psychiatric illness such as schizophrenia, bipolar disorder and major depressive disorder have not been established. Pfizer developed this study protocol at the request of, and in consultation with, the European Medicines Agency (EMA) to investigate use of varenicline in patients with MDD.
Efficacy resultsThe primary endpoint was the 4-week Continuous Quit Rate (CQR) for weeks 9 through 12. Subjects were treated for 12 weeks and followed for up to 52 weeks. The key secondary endpoint was Continuous Abstinence Rate (CAR) from weeks 9 through 52. Subjects in the varenicline-treated group had a higher likelihood of quitting smoking at the end of the treatment period. The CQR between weeks 9-12 was 35.9% for varenicline vs. 15.6% for placebo and between weeks 9-52 was 20.3% vs. 10.4%, respectively. The efficacy results from this study were consistent with varenicline pivotal trials. Safety results The most commonly reported AEs in greater than or equal to 10% of subjects were: nausea, headache, abnormal dreams, irritability and insomnia.