Alkermes puzzled by FDA's stance on depression drug

Shares in Ireland-headquartered firm Alkermes closed 22% down on Monday at $45.23, a market reaction prompted by the US Food and Drug Administration’s (FDA) Refusal to File letter relating to the New Drug Application (NDA) for a proposed depression treatment.

The letter concerned ALKS 5461, a once-daily, oral investigational medicine with a novel mechanism of action for the adjunctive treatment of major depressive disorder (MDD) in patients with an inadequate response to standard antidepressant therapies.

"We strongly believe that the clinical development program provides substantial evidence of ALKS 5461's consistent antidepressant activity"