Olanzapine Plus Samidorphan in Subjects with Schizophrenia and Comorbid Alcohol Use Disorder: Rationale and Design for a Phase II, Double-blind, Randomized Study.

Alcohol use disorder (AUD) is a common comorbidity in patients with schizophrenia. Although pharmacological options for the management of each disease exist separately, there is no agent approved for both. Moreover, studies conducted in this patient population, who face practical and social challenges as a consequence of being diagnosed with schizophrenia and comorbid AUD, are limited. We describe the design of a Phase II, double-blind, randomized trial to evaluate adult outpatients with schizophrenia and comorbid AUD receiving a combination of olanzapine plus samidorphan (OLZ+SAM; ALKS 3831), a novel entity currently under development for the treatment of schizophrenia. The combination drug formulation of OLZ+SAM is intended to provide the antipsychotic efficacy of OLZ while mitigating the weight gain and concomitant metabolic abnormalities commonly associated with OLZ alone. In considering this patient population, the novel primary efficacy endpoint is the time from randomization to the first event of exacerbation of disease symptoms (EEDS) based on the occurrence of any of eight prespecified events related to worsening of disease symptoms and/or AUD, as confirmed by a blinded independent adjudication committee. The rate and number of EEDS, improvement in drinking level, and the safety and tolerability of OLZ in combination with SAM will also be assessed. A limited number of studies have been conducted in patients with schizophrenia and AUD, and the need for further research in this difficult-to-study population is well documented. This study is, to our knowledge, the largest and longest trial with a randomized, double-blind, active-controlled design. In addition to providing evidence for the development of OLZ+SAM (ALKS 3831) as a therapeutic option, the study aims to provide insights into the clinical management of subjects with schizophrenia and comorbid AUD. Clinical trials NCT02161718, registered May 2014; EudraCT Number: 2014-001211-39.