Efficacy and Safety of Lumateperone for Major Depressive Episodes Associated With Bipolar I or Bipolar II Disorder: A Phase 3 Randomized Placebo-Controlled Trial

Objective: In a phase 3 randomized double-blind placebo-controlled study, the authors investigated the efficacy and safety of 42 mg/day of lumateperone in patients with bipolar I or bipolar II disorder experiencing a major depressive episode.

Methods: Patients 18-75 years old with a clinical diagnosis of bipolar I or bipolar II disorder and experiencing a major depressive episode were eligible for the study. Patients were randomized in a 1:1 ratio to receive 42 mg/day of lumateperone (N=188) or placebo (N=189), administered orally once daily in the evening for 6 weeks. The primary and key secondary efficacy endpoints were change from baseline to day 43 in score on the Montgomery-Åsberg Depression Rating Scale (MADRS) and total score on the Clinical Global Impressions Scale-Bipolar Version severity scale (CGI-BP-S), respectively. Safety assessments included treatment-emergent adverse events, laboratory parameters, vital signs, extrapyramidal symptoms, and suicidality.

Results: At day 43, lumateperone treatment was associated with significantly greater improvement from baseline in MADRS score compared with placebo (least squares mean difference compared with placebo, -4.6 points; effect size=-0.56) and CGI-BP-S total score (least squares mean difference compared with placebo, -0.9; effect size=-0.46). Significant MADRS superiority for lumateperone over placebo was observed both in patients with bipolar I and bipolar II disorders. Somnolence and nausea were the only treatment-emergent adverse events that occurred with lumateperone at a clinically meaningful greater rate than placebo. The incidence of extrapyramidal symptom-related treatment-emergent adverse events was low and similar to that for placebo. Minimal changes were observed in weight, vital signs, or metabolic or endocrine assessments.

Conclusions: Lumateperone at 42 mg/day significantly improved depression symptoms and was generally well tolerated in patients with major depressive episodes associated with both bipolar I and bipolar II disorders.