October 17, 2014 — Pfizer has tried and failed to get the FDA to remove a “Black Box” warning on Chantix, according to the Wall Street Journal.
In July 2009, the FDA added a boxed warning about suicide, hostility, depression, and bizarre violent behavior to the label on Chantix. The warnings were added based on voluntary adverse event reports. Because they came from a population of uncertain size, the FDA was not able to determine the risk or establish a causal relationship.
Pfizer argues that studies do not show an increase in suicidal thoughts or actions when Chantix was compared to a placebo. As evidence, they cited five studies that evaluated suicidal ideation and behavior. None of the individual trials showed any significant difference in psychiatric events.
The FDA disagreed, pointing out “concerns about the validity” of the studies submitted by Pfizer. There is also “limited precedent” for removing boxed warnings, but they suggested that data collected by Pfizer could be included in a label update. Eleven advisors to the FDA voted to keep the warning, stating:
“[FDA is] not inclined to remove the boxed warning at this time because of the concern that such action could be interpreted as confirming ‘no association’ between [Chantix] use and neuropsychiatric risk, which is not supported by currently available observational data.”
Chantix works by blocking nicotine from producing the “feel-good” brain chemicals that make smoking so addictive. Within 18 months after Chantix was approved in 2006, the FDA had received 260 adverse events involving suicidal behavior or other psychiatric disorders.
Between 2009 and 2012, Pfizer was hit with about thousands of lawsuits from people who were injured by Chantix. Approximately 2,700 cases were centralized in federal court in Alabama. Last year, Pfizer settled most of the lawsuits for nearly $300 million.