Pfizer said its smoking cessation drug Chantix/Champix (varenicline) has failed to achieve its primary endpoint in a phase 4 study.
The trial assessing the efficacy and safety of vareniclin for smoking cessation in nicotine dependent adolescents between 12 years and 19 years of age did not achieve its primary endpoint of the four-week continuous abstinence rate at weeks nine through 12 compared against placebo.
The phase 4 trial is a randomized, double-blind, placebo-controlled, parallel-group and dose-ranging multicenter study designed to evaluate the safety and efficacy of varenicline along with age-appropriate counseling for smoking cessation in nicotine dependent adolescents.
Pfizer has placed patients in two cohorts based on body weight. Following two-week titration, patients randomized to varenicline with a body weight greater than 55kg secured 1mg twice daily and patients with a body weight less than 55kg received 0.5mg twice daily or 0.5mg once daily.
Pfizer provided treatment to patients for 12 weeks, which is followed by a non-treatment period of 40 weeks.
Under planned regulatory interactions in the US and EU, the company will submit data to the US Food and Drug Administration for Chantix pediatric exclusivity determination.
Chantis, which is also called as Champix in the EU and other countries, secured approval from the US Food and Drug Administration in May 2006 as a prescription medication to help adults aged 18 years and above stop smoking.
According to Pfizer, Chantix secured approval in over 100 countries for adults aged 18 and over, and has been prescribed to more than 24 million patients across the world.
Pfizer internal medicine chief development officer Dr James Rusnak said: “This study makes a valuable contribution to the limited body of clinical research on pharmacotherapy smoking cessation treatments for adolescent smokers.
“CHANTIX/CHAMPIX is an important treatment option for adults 18 and over who want to quit smoking.”