ALK21-003EXT: An Extension of Study ALK21-003 (NCT01218958) to Test the Long-term Safety of Medisorb® Naltrexone (VIVITROL®)

All participants in this study received Medisorb naltrexone at double-blinded dose strengths (ie, 190 mg or 380 mg); no participant received placebo. Participants who had received Medisorb naltrexone in Study ALK21-003 (NCT01218958) continued to receive the same dose strength in this extension study. Those who had received placebo for Medisorb naltrexone 190 mg in the base study were given Medisorb naltrexone 190 mg. Participants who had received placebo for Medisorb naltrexone 380 mg in the base study were given Medisorb naltrexone 380 mg.

Neither the identity or dose of the treatment received in the base study, nor the Medisorb naltrexone dose strength (190 mg or 380 mg) received in this extension were revealed to any participant, the investigator, or any blinded member of the clinical study team during the conduct of the base study or this extension.

All participants were encouraged to receive standardized biopsychosocial support at each clinic visit throughout the study; however, unlike the base study, participation was not mandatory.

Participants eligible for this extension study had received all 6 injections of study drug in the base study; those who received Medisorb naltrexone in the base study who also received all 13 injections in this extension therefore had a duration of exposure of approximately 76 weeks (~1.5 years) upon completion of this extension. For participants who had received placebo in the base study, maximum duration of exposure was approx. 48 weeks (1 year).