CAMBRIDGE, Mass.--(BUSINESS WIRE)--Alkermes, Inc. (NASDAQ: ALKS) today announced the initiation of a phase 3 clinical trial of VIVITROL® (naltrexone for extended-release injectable suspension) for the treatment of opioid dependence. The multi-center study is designed to assess the efficacy and safety of VIVITROL in approximately 200 patients diagnosed with opioid dependence. The clinical data from this study will form the basis of a supplemental New Drug Application (sNDA) to the U.S. Food and Drug Administration (FDA) for VIVITROL for the treatment of opioid dependence, a chronic brain disease.