Amylin's diabetes drug Bydureon approval delayed again by US FDA call for more clinical data; 3rd qtr sales data

Amylin Pharmaceuticals (Nasdaq: AMLN) received a disappointment yesterday, when the increasingly risk-averse US Food and Drug Administration issued a complete response letter regarding the firm’s New Drug Application for its type 2 diabetes drug candidate Bydureon (exenatide extended-release for injectable suspension), calling for additional clinical data.

The drug, which is a once-weekly version of the already marketed Byetta, is partnered with Eli Lilly (NYSE: LLY) and Alkermes (Nasdaq: ALKS) and currently generates sales of around $700 million a year. This is the second complete response letter received from the FDA (The Pharma Letter March 16). The FDA also took a long time - around two years - to approve Danish insulin giant Novo Nordisk’s Victoza (liraglutide) on safety concerns; that drug was finally cleared by the agency at the beginning of this year, though it had to carry a warning about the risk of thyroid cancer (TPL January 20).

In the letter to Amylin, the FDA requested a thorough QT (tQT) study with exposures of exenatide higher than typical therapeutic levels of Bydureon. The tQT protocol will be agreed to by the FDA prior to study initiation. Additionally, the FDA has now requested the results of the DURATION-5 study to evaluate the efficacy, and the labeling of the safety and effectiveness, of the commercial formulation of Bydureon. This letter did not cite any manufacturing processes referenced in the FDA's March 15 complete response letter. REMS and product labeling discussions will continue following submission of the additional data.