Pfizer preps its case for FDA pulling Chantix's black-box warning

The FDA polished up the official label on Pfizer's stop-smoking drug Chantix earlier this week. It was a victory for Pfizer ($PFE), the payoff from several studies testing the drug for psychiatric side effects. Essentially, the new label will include study data suggesting that patients using the drug might not be at a greater risk of psychiatric problems after all.

Now, the drugmaker says it's asking the agency to yank the drug's black-box warning altogether. "Based on all this new information, a boxed warning is not supported," Pfizer SVP Steve Romano told the Associated Press. "The bottom line is that the label needs to reflect the most current understanding of the product's benefits and risks."

Pfizer appears to be stoking up its argument for an Oct. 16 advisory committee meeting, where the experts will weigh that new study data and consider changing the black-box warning.

According to the committee agenda, the group will look at data from observational studies and a meta-analysis of controlled trials conducted after the original side-effects reports emerged. Among them could be a follow-up study Pfizer conducted in patients with depression, which found no difference in psychiatric problems between the Chantix arm and the control arm.

Chantix came under fire soon after its 2006 launch, as reports of suicidal depression, intense anger and other psychiatric troubles surfaced. The drug briefly turned notorious when a semifamous Dallas musician and Chantix user, Carter Albrecht, went into an angry fit and was shot and killed by his neighbor. Thousands of side-effect reports rolled in after the news aired. A U.S. soldier blamed Chantix for his sudden, brutal stabbing of a fellow recruit at Fort Benning, GA, but a jury didn't buy the argument; he was sentenced to life in prison.

After a review of the side-effects reports and other data, the FDA added a black-box warning about psychiatric side effects back in 2009, including hostility, agitation, depressed mood and suicidal thoughts or actions. And that's the warning that's up for review now.

As The Wall Street Journal's Pharmalot blog reports, the Institute for Safe Medicine Practices is trying to counter Pfizer's argument. A top scientist there says there's plenty of evidence out there suggesting that Chantix causes psychiatric side effects, namely in side-effect reports to the FDA. The group also takes issue with Pfizer's safety analyses. In fact, the group plans to ask the agency to strengthen the black-box warning, rather than remove it.

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