Pfizer Inc.’s (PFE) Chantix, a smoking cessation medicine, is back making headlines – this time getting good press. Chemically known as Varenicline, the drug is marketed under the brand name Champix in Canada, Europe Australia and other countries. Approved by the FDA in 2006, Chantix in its early days was lauded for its effectiveness in helping people to quit smoking. Very soon its spotlight dimmed as the drug came to be linked with reports of serious side effects like suicide and depression. The Federal Aviation Administration in May 2008 banned pilots and air traffic controllers from using Chantix, following a medical safety group’s report warning of the drug’s side effects such as loss of consciousness and seizures. In July 2009, the FDA required Pfizer to put a Boxed Warning on the Chantix label, highlighting the risk of serious neuropsychiatric (NPS) events when using the drug. But Chantix’s safety problems didn’t end there. On June 16, 2011, the FDA updated Chantix’s label to warn consumers that the drug may be associated with a small, increased risk of certain cardiovascular adverse events in patients who have cardiovascular disease. Ever since the first lawsuit against Chantix was filed in July 2008 in federal court in Indiana by the widow of a man who committed suicide a few months after using the drug, there had been nearly 3,000 Chantix lawsuits. However, all the lawsuits related to Chantix were settled by Pfizer by June 2013. Meanwhile, Pfizer has been working towards getting the labeling language on Chantix softened, but to no avail.
Last October, an FDA panel, which reviewed Pfizer’s request proposing changes to Chantix’s labeling relating to the risk of serious neuropsychiatric adverse events, voted to maintain the Black Box warning on the drug. With very little competition and huge unmet medical need, Chantix was poised to be a blockbuster drug. But safety concerns have pulled down the drug’s prospects as can be seen by the sales figures. YearSales2007$883 Mln2008$846 Mln2009$700 Mln2010$755 Mln2011$720 Mln2012$670 Mln2013$648 Mln2014$647 Mln Now, supporters of Chantix have a good reason to smile… A study led by researchers from the Universities of Edinburgh and Dusseldorf, which assessed the cardiovascular and neuropsychiatric safety of Chantix using data from the QResearch general practice (GP) database, suggests that Chantix is not associated with an increased risk of documented cardiovascular events, depression, or self-harm when compared with nicotine replacement treatment, or NRT. As part of the research, 164,766 adult patients who received prescriptions for Chantix and other smoking cessation aids like Zyban or NRT between Jan 1, 2007, and June 30, 2012 were studied.
Pfizer, the manufacturer of Chantix and GlaxoSmithKline, the manufacturer of Zyban were not involved during any stage of this project. An analysis of the data shows that neither Chantix nor Zyban showed any evidence of increased risk of any neuropsychiatric or cardiovascular event compared with NRT. Commenting on the findings, Professor Aziz Sheikh, Co-Director of the University of Edinburgh’s Centre for Medical Informatics, said “On the basis of our extensive analysis, we believe it is highly unlikely that Varenicline has any significant adverse effects on cardiac or mental health. Regulators such as the FDA should review its safety warning in relation to Varenicline as this may be unnecessarily limiting access to this effective smoking cessation aid.” The study is published in The Lancet Respiratory Medicine. Pfizer is conducting a large clinical safety trial evaluating the neuropsychiatric safety of Chantix versus placebo, NRT and Zyban in patients with and without prior history of psychiatric conditions. Results from this study are expected in late 2015.