FDA declines to review Alkermes' antidepressant

Alkermes plc (NASDAQ:ALKS) sank $12.73 (22%) to $45.23 on Monday after it said FDA issued a refusal-to-file letter for its NDA for ALKS 5461 as an adjunctive treatment for major depressive disorder (MDD) in patients with an inadequate response to standard antidepressants. The company plans to appeal the decision, and hopes to meet with FDA to discuss a resubmission.

Alkermes said FDA believes it cannot complete a review of the NDA "based on insufficient evidence of overall effectiveness" in the indication, and will require additional controlled clinical trials before a resubmission. The agency also has requested a bioavailability study to generate bridging data between ALKS 5461 and buprenorphine, Alkermes said. ALKS 5461 combines samidorphan (ALKS 33), which is a mu opioid receptor (OPRM1; MOR) antagonist, with buprenorphine...