US FDA calls for more efficacy data on Pfizer's tafamidis NDA

The US Food and Drug Administration yesterday issued a complete response letter regarding drugs behemoth Pfizer’s (NYSE: PFE) New Drug Application for tafamidis meglumine, requesting the completion of a second efficacy study to establish substantial evidence of effectiveness prior to an approval. The Agency has also asked for additional information on the data within the current tafamidis NDA.

Tafamidis is a novel, investigational medication for the treatment of transthyretin familial amyloid polyneuropathy (TTR-FAP) in adult patients with symptomatic polyneuropathy to delay neurologic impairment.

Last month, the FDA’s Peripheral and Central Nervous System Drugs Advisory Committee did not find substantial evidence of efficacy on a clinical endpoint. The Committee then voted 13 to four that the data backing Pfizer’s NDA provide substantial evidence of efficacy for a surrogate endpoint that is reasonably likely to predict a clinical benefit (The Pharma Letter May 25). Around a year ago the FDA issued a refusal to file letter on tafamidis. Pfizer said it will work with the FDA to address the content of the letter.