Pfizer Inc.  announced results from a phase 4 study evaluating the efficacy and safety of Chantix/Champix (varenicline) for smoking cessation in nicotine dependent adolescents 12-19 years of age. The study did not meet its primary endpoint of the four-week continuous abstinence rate at weeks 9 through 12 for Chantix/Champix compared to placebo. The study is a regulatory post marketing commitment for Chantix/Champix in the US and EU for adolescents 12-16 years and 12-17 years of age, respectively.

“This study makes a valuable contribution to the limited body of clinical research on pharmacotherapy smoking cessation treatments for adolescent smokers,” said James Rusnak, M.D., Ph.D., chief development officer, internal medicine, Pfizer Inc. “Chantix/Champix is an important treatment option for adults 18 and over who want to quit smoking.”

The adverse event profile of Chantix/Champix observed in this study of adolescent smokers was similar to that seen in studies of adults. The most common adverse events that occurred in at least 5 per cent of patients were nausea, headache, vomiting, agitation, and abnormal dreams (high dose group); and nausea, dizziness, agitation, abnormal dreams, and upper respiratory tract infection (low dose group).

This randomized, double-blind, placebo-controlled, parallel-group, dose-ranging multicenter study examined the safety and efficacy of varenicline, along with age-appropriate counseling, for smoking cessation in nicotine dependent adolescents (n=312). Patients were stratified into two cohorts by body weight (=55 kg and >55 kg). Following two-week titration, patients randomized to varenicline with a body weight >55 kg received varenicline 1 mg twice daily (high dose group) or 0.5 mg twice daily (low dose group), while patients with a body weight =55 kg received 0.5 mg twice daily (high dose group) or 0.5 mg once daily (low dose group). Patients received treatment for 12 weeks, followed by a non-treatment period of 40 weeks. The study was not powered to assess efficacy in adolescent smokers aged 17-19 and in this group conclusions cannot be drawn.

Complete study results will be submitted for presentation at an upcoming scientific congress and for publication in a peer-reviewed medical journal. As part of planned regulatory interactions in the US and EU, these data will be submitted to the US Food and Drug Administration for Chantix pediatric exclusivity determination.

Chantix (also known as Champix in the EU and other countries) was approved by the FDA in May 2006 as a prescription medication that, along with support, helps adults aged 18 and over stop smoking. Chantix is approved in more than 100 countries for adults aged 18 and over and has been prescribed to more than 24 million patients worldwide.