Lawsuit Over Generic Chantix Version Filed by Pfizer

Pfizer has filed a patent infringement lawsuit against Mylan over its plans to market a generic version of Chantix, the popular smoking cessation drug that has come under fire for side effects linked to suicidal and violent behavior. 

The generic Chantix lawsuit was filed in federal court in New York on Monday by the drug maker, who says that Mylan is infringing on two patents that cover their controversial medication. Mylan has filed an abbreviated new drug application (ANDA) with the FDA, announcing its intentions to market Chantix generic, but Pfizer says that the patents it holds should prevent Chantix clones from hitting the market until 2020.

Mylan stated in its FDA ANDA that the Chantix patents are either invalid or unenforceable.

Chantix (varenicline) was approved in the United States by the FDA in 2006 as a prescription medication to help people quit smoking. The drug works by reducing the positive feelings that come from cigarettes, blocking the receptors in the brain commonly stimulated by nicotine. However, the impact of the drug on the brain has resulted in a number of reports from users who experienced sudden, unusually aggressive behavior, thoughts of self-harm and suicide.

In June 2009, a “black box” warning was added to the medication about the potential risk of problems with Chantix, indicating that some users have experienced changes in behavior, depression and suicidal thoughts. Pfizer has also been required to conduct clinical trials providing more data on how often neuropsychiatric symptoms and suicide with Chantix occur and what conditions cause them.

A growing number of lawsuits over Chantix have been filed in state and federal courts throughout the United States on behalf of individuals who have suffered injuries from the neuropsychiatric side effects of the medication, skin reactions from Chantix and for family members of individuals who have committed suicide on Chantix.

In October 2009, the U.S. Judicial Panel on Multidistrict Litigation consolidated all federal Chantix injury lawsuits in the U.S. District Court for the Northern District of Alabama. According to a pretrial scheduling order issued earlier this year, the first Chantix trial is unlikely to reach a jury until at least 2012.