Alkermes plc (NASDAQ: ALKS) today announced that it has successfully completed its End-of-Phase 2 interactions with the U.S. Food and Drug Administration (FDA), and the company plans to advance ALKS 5461 into phase 3 development in early 2014. Alkermes is developing ALKS 5461 for the treatment of patients with major depressive disorder (MDD) who have inadequate response to standard therapies. The company and the FDA agreed on key elements of the development program, including preclinical and clinical requirements for the New Drug Application, the confirmatory study plans, the incorporation of innovative study designs that include the use of sequential parallel comparison design (SPCD), the primary endpoint and the statistical methodology. In September 2013, in advance of a planned End-of-Phase 2 meeting, Alkermes submitted a written briefing document detailing design elements of the proposed development program. The FDA’s written responses aligned with the company’s proposals such that the End-of-Phase 2 meeting was deemed unnecessary. “We prepared a robust and innovative clinical trial plan and are pleased with the FDA’s positive feedback that enables us to move directly into the ALKS 5461 phase 3 program in early 2014,” said Elliot Ehrich, M.D., Chief Medical Officer of Alkermes. “There is a clear and compelling need for a novel mechanism for the treatment of depression, and ALKS 5461 reflects a new approach based on modulation of the opioid system in the brain.” About ALKS 5461 ALKS 5461 is a proprietary investigational medicine with a novel mechanism for the treatment of major depressive disorder (MDD). The mechanism of action for ALKS 5461 in the treatment of depressive symptoms is based on modulation of the opioid system in the brain, employing a balanced combination of agonism and antagonism of opioid receptors. ALKS 5461 consists of buprenorphine, a partial agonist, and ALKS 33, a potent mu-opioid antagonist, and is designed to be a once-daily, non-addictive medicine. Early clinical development of ALKS 5461 was funded through a grant from the National Institute on Drug Abuse.