Trial supports safety and efficacy profile of Pfizer’s varenicline

Pfizer has announced data from the largest ever randomised clinical trial of approved smoking cessation medicines, called EAGLES (Evaluating Adverse Events in a Global Smoking Cessation Study). 

EAGLES is the largest placebo-controlled trial to compare the neuropsychiatric safety and efficacy of Champix (varenicline) and bupropion to placebo and nicotine patch to help people quit smoking.

The results demonstrated the use of varenicline or buproprion in patients with or without a history of psychiatric disorder is not associated with an increased risk of serious neuropsychiatric adverse events.   In addition, patients taking varenicline in EAGLES showed statistically superior continuous abstinence rates at weeks 9-12 and 9-24 than patients treated with placebo, bupropion or nicotine patch during both time periods. Patients treated with each of the medications had higher abstinence rates than those treated with placebo.

Commenting on the results, Robert West, Professor of Health Psychology, University College London and co-author of the EAGLES study, said: “This study should reassure regulatory authorities, doctors and patients about the safety and effectiveness of medicines to help smokers to stop, whether or not those smokers have a history of a psychiatric disorder. Every smoker should receive the offer of evidence-based support to stop at least once a year – currently most do not.”

Patients taking varenicline had higher continuouse abstinence rates

The EAGLES study was designed to compare the neuropsychiatric safety of varenicline and bupropion with placebo and nicotine patch in adult smokers with and without a history of psychiatric disorders. Half of the trial participants had a history of psychiatric disorders, either past and in remission, or present and clinically stable. The trial did not show a significant increase in the incidence of the composite primary safety endpoint of serious neuropsychiatric adverse events with varenicline or bupropion compared to placebo and nicotine patch.

EAGLES also included an efficacy objective to determine smoking abstinence rates in patients treated with varenicline or bupropion, relative to placebo, during the last four weeks of the 12-week treatment period. Continuous abstinence was also evaluated relative to the nicotine patch. In addition, long-term abstinence through a 12-week non-treatment follow-up period (weeks 9-24) was evaluated for all treatments. The results showed that patients with and without a history of psychiatric disorders taking varenicline had significantly higher continuous abstinence rates than patients treated with bupropion or nicotine patch. Patients treated with each of the medications had higher abstinence rates than those treated with placebo during both time periods.