A Study of ALKS 3831 in Adults With Schizophrenia

Phase 2

Completed

Interventions: Drug: Samidorphan (High Dose)
Drug: Placebo
Drug: Samidorphan (Low Dose)
Drug: Samidorphan (Medium Dose)
Drug: Olanzapine

Brief Summary: This is a Phase 2, randomized, placebo-controlled multicenter study, which will be conducted in 2 parts. The study duration for each subject will be approximately 33 weeks and will include 25 study visits.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Initiated 1st antipsychotic treatment within the past 12 months and/or has had symptoms lasting <2 years
Current diagnosis of alcohol or drug use disorder, moderate or severe
Clinically significant or unstable medical illness, condition, or disorder
Pregnant or breastfeeding
Significant changes in diet or exercise regimen or plans to join a weight management program during the study
Opioid medications taken within 14 days and/or need to take opioid medication during the study period
History of hypersensitivity to or intolerance of olanzapine
Use of olanzapine, clozapine, mesoridazine, chlorpromazine, or thioridazine for more than 1 week during the past year

Arm && Interventions

Group	Intervention	Description
High Dose	Samidorphan (High Dose)	Olanzapine + high dose samidorphan tablets taken once daily
Placebo	Placebo	Olanzapine + placebo tablets taken once daily
Low Dose	Samidorphan (Low Dose)	Olanzapine + low dose samidorphan tablets taken once daily
Medium Dose	Samidorphan (Medium Dose)	Olanzapine + medium dose samidorphan tablets taken once daily
Medium Dose	Olanzapine	Olanzapine + medium dose samidorphan tablets taken once daily
Placebo	Olanzapine	Olanzapine + placebo tablets taken once daily
Low Dose	Olanzapine	Olanzapine + low dose samidorphan tablets taken once daily
High Dose	Olanzapine	Olanzapine + high dose samidorphan tablets taken once daily

Primary Outcome Measures

Name	Time	Method
Absolute Change in Total Positive and Negative Syndrome Scale (PANSS) Score	Baseline (Day 8) to Day 92 (end of study Part A)	Change from baseline (Day 8) to Day 92 (end of study Part A). The PANSS is a 30-item scale measuring severity of schizophrenia symptoms. Symptom severity for each item is rated on a 7-point scale (1 = absent; 7 = extreme), and the total score is added together, with a minimum score of 30 and a maximum score of 210. A higher score indicates more severe symptoms, while a lower score indicates less severe symptoms.

Secondary Outcome Measures

Name	Time	Method
Percentage of Subjects Exhibiting Significant Weight Gain at Day 92	Baseline (Day 8) to Day 92 (end of study Part A)	Significant weight gain will include a \>=5%, \>= 7%, or \>=10% gain in body weight from baseline (Day 8) to Day 92 (end of study Part A)
Change in Clinical Global Impressions - Severity (CGI-S) From Baseline to Day 92	Baseline (Day 8) to Day 92 (end of study Part A)	Change in CGI-S score from baseline (Day 8) to the end of Part A (Week 12; Day 92). The CGI-S is a 7-point scale intended to measure the severity of a patient's illness at the time of assessment. Scores range from 1 (normal) to 7(extremely ill), so a higher score is correlative to more severe illness.
Percent Change in Body Weight (Kilogram) From Baseline to Day 92	Baseline (Day 8) to Day 92 (end of study Part A)	Percent change from baseline (Day 8) to the end of Part A (Day 92)
Absolute Change in Body Weight (kg) From Baseline to Day 92	Baseline (Day 8) to Day 92 (end of study Part A)	Change from randomization (Day 8) to the end of Part A (Week 12; Day 92)