Sunovion and Otsuka Initiate Phase 3 Clinical Development of Treatment for Bipolar Depression

Sunovion Pharmaceuticals Inc. and Otsuka Pharmaceutical Development & Commercialization, Inc. announced that the first patient has been randomized in SEP380-301, a Phase 3 clinical study evaluating non-racemic amisulpride (SEP-4199) for the treatment of major depressive episodes associated with bipolar I disorder (bipolar depression). Non-racemic amisulpride is being jointly developed and commercialized as part of a collaboration between Sunovion, its parent company Sumitomo Dainippon Pharma and Otsuka Pharmaceutical Co., Ltd.

SEP380-301, named RELEASE 1 (NCT05169710), is a six-week, global, multicenter, randomized, double-blind, placebo-controlled, parallel-group study examining the efficacy, safety and tolerability of non-racemic amisulpride in adults with bipolar depression. Patients will be randomized to receive fixed-dose, non-racemic amisulpride (200 or 400 mg/day) or placebo. 

The primary endpoint for RELEASE 1 is the reduction of depressive symptoms, as measured by the change from baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) total score, compared to placebo, after six weeks of treatment. Following participation in the six-week study period, patients who complete RELEASE 1 may enroll in RELEASE 3 (SEP380-303; NCT05227209), a 12-month, open-label extension study assessing the long-term safety, tolerability and effectiveness of non-racemic amisulpride.

“Major depressive episodes associated with bipolar I disorder have a profound impact on those living with the condition. Depressive episodes are associated with mood impairment, fatigue, loss of interest in activities or social situations and, in some cases, suicidality,” said Armin Szegedi, M.D., Ph.D., Senior Vice President, Chief Medical Officer at Sunovion. “We are encouraged by our Phase 2 clinical results and look forward to enhancing our understanding of non-racemic amisulpride and its potential to help address unmet needs in the treatment of bipolar depression.”

“Randomizing the first patient in the RELEASE Phase 3 clinical development program is a significant step in our collaboration with Sunovion and our shared goal of expanding neuropsychiatric treatment options to patients living with serious mental conditions,” said John Kraus, M.D., Ph.D., Vice President, Clinical Development Therapeutic Head, CNS, Otsuka Pharmaceutical Development & Commercialization, Inc. “Through our collaboration with Sunovion, we hope to advance SEP-4199, which we believe shows promise for the treatment of people with bipolar depression.”