The drug maker had sought to remove a so-called Black Box warning noting the risk of psychiatric side effects, such as suicidal thoughts and behavior, in hopes reviving the fortunes of a medicine that was once seen as a blockbuster, but has since sputtered among sensational news accounts and litigation.
Shortly after Chantix was approved in 2006, the pill became associated with stories of suicide and violence, which dampened use. Sales fell to $648 million last year from $846 million in 2008. And Pfizer spent hundreds of millions of dollars to settle hundreds of lawsuits.
Last month, however, the FDA altered another portion of the Chantix label portion of the Chantix label to indicate the pill may not carry the risks of suicidal thoughts and behavior. That change was part of an effort by Pfizer to lessen concerns about prescribing and usage, which have fallen since the Black Box was issued in 2009.
To persuade the FDA panel, Pfizer pointed to a meta-analysis of five studies the drug maker says did not show an increase in suicidal activity compared to those on a placebo. Pfizer also cited four observational studies involving thousands of patients the drug maker claimed did not show an increased risk (see here, here, here and here).
But 11 members of an FDA advisory panel voted to recommend the agency maintain the Black Box warning, while six members voted to strengthen the labeling, suggesting that references to sleep disturbances, for instance, should be added. Only one panel voted in favor of removing the Black Box.
The panel also recommended that any further thought to changing the warnings should not be considered until after Pfizer completes a promised post-marketing study, which the drug maker expects to finish in the third quarter of 2015.
The panel, essentially, took the same position as FDA staffers, who questioned the designs of the observational studies. Several consumer groups recently cited both the study designs and thousands of side effect reports to petition the FDA to increase the Chantix warnings.
“I think Pfizer took quite a chance trying to get the box deleted. They obviously wouldn’t have done it if they thought they could convince people, but they failed completely,” says Diana Zuckerman, the president of the National Center for Health Research, a non-profit think tank.
“They had the best presentation money could buy – very good analyses and complicated statistics to prove their point. And the company trotted out these studies and tried to make a very strong case for why the Black Box should be deleted, but only one person voted their way.
“Pfizer took a big chance, but I think they did so because they were afraid the next study wouldn’t be so favorable and maybe they could get rid of the Black Box warning now. Remember, if it were removed, it would be hard to get it reinstated later, even if a post-marketing study showed risk.”
Pfizer is not flinching. “The completion of our currently ongoing safety study will represent one more step forward in the process of accurately characterizing the neuropsychiatric safety of this important medication,” says Steven Romano, a Pfizer senior vp who heads the medicines development group.
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