Pfizer remains upbeat about getting approval for tafamidis despite advisors to the US Food and Drug Administration saying they did not find enough evidence of efficacy for the proposed treatment for patients with transthyretin familial amyloid polyneuropathy.

The FDA's Peripheral and Central Nervous System Drugs Advisory Committee has concluded a meeting on the clinical data package for tafamidis. Panellists were not asked on whether to recommend approval of the drug, developed by Pfizer subsidiary FoldRx, for TTR-FAP, a progressive and fatal neurodegenerative disease that affects some 8,000 patients worldwide (including about 3,000 Americans).

The committee did vote 13-4 that the data did not show "substantial evidence of efficacy on a clinical endpoint", That point of view echoed highly critical documents issued by one FDA staffer earlier in the week which recommended outright that a complete response letter for tafamidis should be issued.

However, the panel then voted 13-4 that the data "provide substantial evidence of efficacy for a surrogate endpoint that is reasonably likely to predict a clinical benefit". Yvonne Greenstreet, and head of the medicines development group for Pfizer’s specialty care business unit, noted that TTR-FAP "is an irreversible and devastating disease with no FDA-approved treatment", adding that "the  panel’s assessment represents a positive step forward".

She went on to say that  Pfizer will continue to work with the FDA as the agency finalises its review". Tafamidis, which has been granted orphan drug status and a priority review, was approved by the European Commission last November, with the brand name Vyndaqel.