UPDATED: In rare slap, FDA review rips up Pfizer's case for tafamidis

Pfizer gambled big when it took data from a single study to back its application for tafamidis as a treatment for a rare neurodegenerative disease. And an FDA review of the data concludes decisively that the company lost. After considering the trial's failure to meet its co-primary endpoints and questioning the data gathered at 8 sites, the agency is recommending that the experts gathering to discuss the drug's fate on Thursday reject the therapy.

"I recommend a Complete Response action, based on inadequate evidence of effectiveness," stated the FDA reviewers in a rare, outright slap at an application. The agency isn't bound by either the review or the panel vote on Thursday, but Pfizer's ($PFE) team will face an uphill struggle when it makes its case for tafamidis--a therapy for familial amyloid polyneuropathy--later in the week.

In the review, the agency investigator picks apart the data, wondering why most of the responders were clustered in one site while 7 other sites offered little by way of supporting data. "Overall, Study 005 does not have the characteristics of a single adequate and well-controlled study that could make the study adequate support for an effectiveness claim," the review states.

Pfizer, though, plans to put its case on the drug in the best light possible.

"There is currently no FDA-approved treatment designed specifically to treat TTR-FAP," Pfizer noted in a statement to FierceBiotech this morning. "If approved by the FDA, tafamidis will be the first and only medication in the U.S. to treat patients with this debilitating genetic disease. Pfizer believes that the data for tafamidis provide substantial evidence of effectiveness and meaningful therapeutic benefit where there is a high unmet medical need. We look forward to discussions with the FDA and its Advisory Committee to further the understanding of TTR-FAP and the data supporting our NDA."

Pfizer landed tafamidis when it acquired FoldRx in a buyout back in 2010 as it pushed into the rare disease field. Like other pharma companies, Pfizer was lured by the prospect of big returns for drugs that meet an urgent need in tiny patient populations. About 8,000 people around the world, including 2,500 in the U.S., suffer from the neurodegenerative disease Pfizer was focused on. But the pharma giant, which is still trying to shed its reputation as a poster child for clinical ineptitude, may be rethinking the business plan this morning.

- here's the FDA review
- read the story from Reuters