October 15, 2014
By Jessica Wilson, BioSpace.com Breaking News Staff
The Food and Drug Administration (FDA) on Tuesday issued the opinion that Pfizer Inc. , the New York, N.Y.-based pharmaceutical company, should retain the severe warning label on its drug Chantix, also known asvarenicline, which is prescribed to help people quit smoking.
An FDA> advisory panel, composed of FDA staff and other experts, will meet on Oct. 16 to vote on this recommendation. While the panel doesn’t have to abide by this opinion, it typically does follow the FDA’s recommendation.
The FDA first placed its most severe warning, also referred to as a “black box warning,” on Chantix in 2009, three years after the drug was approved. The warning lists possible side effects of the drug, such as suicidal thoughts, erratic behavior and drowsiness.
Several consumer groups have petitioned the FDA to issue a warning that people working in certain occupations shouldn’t take the drug. According to the Wall Street Journal, the Federal Aviation Administration (FAA) has already banned its use by pilots and air traffic controllers.
Despite the fact that Pfizer paid $273 million in 2012 to settle lawsuits related to Chantix, the company filed observational post-marketing studies with the FDA with the aim to get the black box warning lifted from the drug.
The Wall Street Journal reports that the FDA staff stated the studies Pfizer submitted had a “design limitation …[that] may underestimate the actual incidence of neuropsychiatric adverse events, and restrict our ability to predict the direction of the relative risk.”
In addition, the staffers wrote that the committee was “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.”
The committee said it would review data after Pfizer completed its post-marketing studies.
When Chantix was approved in 2006, many thought it would be Pfizer’s next “blockbuster” drug and its first full year of sales yielded $883 million.
By 2013, however, sales of the drug had fallen to $684 million, likely because of its side effects, black box warning and the general controversy linked to the drug.
When the consumer groups petitioned the FDA to warn people with certain types of occupations not to take the drug, they also asked that the agency add additional possible side effects, including aggression/violence, psychosis and depression to the black box warning.
According to Reuters, “The FDA received about 48,200 domestic adverse event reports in its latest adverse events reporting system for varenicline [Chantix] between Jan 1. 2008 and Dec. 31, 2013,” which included 572 reports of patients.
“Pfizer is committed to the ongoing study and safety monitoring of its medicines, including Chantix, in an effort to provide healthcare professionals and patients with the most accurate and up-to-date information,” a spokesman told The Wall Street Journal.
In addition, he said that the final results of the post-marketing study are expected in the third quarter of 2015.
