Curiouser and Curiouser with Chantix

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In Lewis Carroll’s Alice in Wonderland, Alice famously said: “It would be so nice if something made sense for a change.” Since Carroll wrote this, many people have cited it to refer to one thing or another that puzzles them. I can now add my name to that list, as it does a spot-on job of expressing my thoughts on the recent FDA reversal in removing its black box warning for the smoking cessation drug Chantix.

On December 16, 2016, the FDA issued a drug safety announcement regaring Pfizer’s request that the black box warning be removed from Chantix. The FDA announcement said the decision was consistent with the recommendations of the September 2016 FDA Advisory Committee meeting. Essentially, their rationale was that the benefits of potential smoking cessation outweighed the health risks with Chantix. The conclusion of the committee was that an FDA ordered clinical trial (the EAGLES study) demonstrated “the risk of serious side effects on mood, behavior, or thinking [for Chantix] is lower than previously thought.” These side effects were what led to the black box warning (Given when there are serious or life-threatening risks when using the medication) on Chantix in the first place.

The risk of these mental health side effects is still present, especially in those currently being treated for mental illnesses such as depression, anxiety disorders, or schizophrenia, or who have been treated for mental illnesses in the past. However, most people who had these side effects did not have serious consequences such as hospitalization. The results of the trial confirm that the benefits of stopping smoking outweigh the risks of these medicines.

Notice the FDA is acknowledging the risks are still there and should be noted in the medication guide. However this assertion is debateable when evidence like that on the website RxISK in “Chantix and Violence” is considered. The cases there were originally reported in the FDA database for adverse drug events.

The results of the EAGLES study were published in the journal Lancet here. As Ed Silverman reported for STAT News, this action resulted in renewed efforts by Pfizer to have the black box warning removed. An earlier attempt in 2014 failed when an FDA panel voted to keep the warning intact. The chief medical officer for Pfizer thought removing the warning would more accurately reflect the neuropsychiatric safety profile for Chantix and allow patients and prescribers make informed decisions about treatment options. Despite the rhetoric here, the real reason was money:

The side effects have plagued the drug ever since it was approved a decade ago and endured horrendous publicity about violent or suicidal behavior. As a result, Pfizer spent hundreds of millions of dollars to settle numerous lawsuits and sales for the pill — once pegged to become a blockbuster — have plateaued, sliding from $846 million in 2008 to $671 million in 2015.

Alan Cassels, a pharmaceutical policy researcher at the University of Victoria, British Columbia, pointed out that the FDA action in December 2016 was unprecedented. Most of the drugs removed from the U.S. market over the past 20 years first carried a black box warning. Remember that according to the FDA, those risks ARE STILL PRESENT with Chantix, The EAGLES study concluded those risks are lower than previously reported and the FDA pragmatically agreed the potential benefit from Chantix outweighed the risks.

Not everyone on the FDA Advisory Committee that recommended the removal agreed. Of the 19 panel members, 10 voted to remove the black-box warning. Four wanted to see changes in the wording, while five others recommended the warning remain.

Thomas Moore, a senior scientist with the Institute for Safe Medication Practices, has also voiced concerns with the EAGLES trial itself, used by the FDA to justify removing the Chantix black-box warning. Critical of the study’s design, Moore and the ISMP thought the trial “was greatly underpowered, used a novel, unvalidated measurement scale, required subjective judgements from study investigators, and detected no meaningful differences among eight treatment arms because of a defective design.”

The ISMP letter to the FDA indicated Chantix (varenicline) was suspected to be the primary drug in 17,900 serious injuries from psychiatric adverse events reported to the FDA, 43% of which were done by health professionals. The cases described a series of behaviors ranging from suicidal and homicidal thoughts to delusions, suicidal behavior and bizarre and reckless aggression. These effects were documented in peer-reviewed studies. And Pfizer paid around $300 million in compensation—to over 2,500 varceline victims—for serious injuries that occurred BEFORE the boxed warning was required.

Moore and ISMP were not alone in expressing concern with the EAGLES trial.  Ed Silverman of STAT reported that Sammy Almashat of Public Citizen pointed out how the study had composite outcomes of both serious and milder symptoms, such as irritability and agitation, that normally occur when people are trying to quite smoking. Almashat was concerned with the precedent in this reversal; black box warnings are usually not reversed, especially on such equivocal evidence.

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 concluding statement from the ISMP letter may be a forewarning of what is to come:

An ambiguous warning can be worse than no warning at all because not only does it render the warning ineffective, it undermines the value of all warnings and the credibility of the FDA. A clear warning does not restrict the access of any patient or physician to this treatment.

“Curiouser and Curiouser,” as Alice would say if she heard about the back-and-forth actions by the FDA. There is more on this topic in another article, “Chantix Tug-of-War.”


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