An FDA advisory panel voted to remove black box warnings on the smoking cessation drug Chantix based on a study suggesting side effects such as suicidal thoughts and hostility are more rare than previously thought. Photo by Vitabello1/Shutterstock
WASHINGTON, Sept. 15 (UPI) -- Warnings that the smoking cessation drug Chantix can cause side effects such as suicidal thoughts and hostility may come off the drug's label based on a new study suggesting the warning is unjustified.
An advisory panel at the U.S. Food and Drug Administration voted to recommend the agency remove the black box warning for the potential of Chantix to cause the side effects, according to the drug's manufacturer, Pfizer.
Chantix has been available for about a decade, with concerns about the neuropsychological effects of the drug popping up almost instantly. Between the concerns about suicide and hostility in patients using the drug, and thousands of lawsuits from some who did take it, the drug has not become the runaway hit it was expected to be.
Pfizer has been working to have the label changed for at least two years but failed over questions with new research. An FDA panel raised questions about a new study, published in April in The Lancet, purporting to show the drug is safe and that patients using the drug did not experience psychological side effects significantly more often than those not on the drug while quitting smoking.
In the study, researchers recruited 8,144 participants between the ages of 18 and 75 who smoked more than 10 cigarettes per day and most of whom had tried to quit at least once before, treating them with either Chantix, the patch or placebo.
Of patients diagnosed with a psychiatric disorder, 6.5 percent of participants on Chantix experienced an adverse psychological effect, compared to 4.9 percent of those given a placebo. Of patients who had not been previously diagnosed with a psychiatric disorder, 1.3 percent of participants on Chantix experienced a side effect, compared to 2.4 percent of those given a placebo.
The vote to recommend changing the label was not unanimous -- 10 members of the board voted to remove it, four voted to change it and five said it should not change -- and almost immediately brought criticism, at least partially based on earlier questions about the study used to justify changing the label.
"A Black Box warning has been rescinded very few times in the past," Sammy Almashat, a researcher associate at the healthcare advocacy group Public Citizen, told STAT. "This could set an ominous precedent. If the FDA rescinds, a company can now go to the agency with a substandard post-marketing trial, point to Chantix and demand the same outcome. We're worried that if the FDA follows through with the recommendation, that this will become a new standard for removing a black box."
The advisory board's recommendation does not mean the FDA will necessarily remove the black box warning on Chantix, which will have to vote separately on whether to remove the warning or change the drug's label at all.
Pfizer has proposed removing the black box warning, but updating the Chantix label to reflect to risk for psychological side effects based on the newer study, called EAGLES, which it thinks will sufficiently warn patients of their potential.
"We are pleased with the Committees' recommendation to remove the boxed warning," Dr. Freda Lewis-Hall, chief medical officer and executive vice president at Pfizer, said in a press release, "and believe this is an important step toward updating the Chantix labeling to more accurately reflect its neuropsychiatric safety profile and help patients and prescribers make informed decisions about treatment options."