Cariprazine as a maintenance therapy in the prevention of mood episodes in adults with bipolar I disorder

IntroductionCariprazine treats acute manic and depressive episodes in bipolar I disorder (BP-I), but its efficacy in preventing relapse of mood episode remains unknown.MethodsIn this phase 3b, double-blind, placebo-controlled study, patients with BP-I with acute manic or depressive episodes (each with/without mixed features), were treated with cariprazine 3.0 mg/day during a 16-week open-label treatment period; those who achieved stable remission within 8 weeks and remained stable for at least another 8 weeks were randomized to receive cariprazine 1.5 or 3.0 mg per day or placebo in the double-blind treatment period for up to 39 weeks. The primary efficacy endpoint was time to relapse of any mood episode. Adverse events (AEs) were assessed.ResultsPatients (440/896) enrolled in the open-label treatment period achieved stability criteria and were randomized to receive cariprazine 3.0 mg/day (n = 148), cariprazine 1.5 mg/day (n = 147), or placebo (n = 145) in the double-blind treatment period. Relapse rates were 17.9%, 16.8%, and 19.7% in the cariprazine 3.0 mg/day, cariprazine 1.5 mg/day, and placebo groups, respectively. Neither dose of cariprazine was more effective than placebo on the primary outcome (3.0 mg/day: HR = 0.89, [95% CI: 0.5, 1.5]; 1.5 mg/day: HR = 0.83, 95% CI [0.5, 1.4]). The most frequently reported AEs (>= 5%) were akathisia, headache, insomnia, and nausea in the open-label treatment period and increased weight and insomnia in the double-blind treatment period. In the open-label and double-blind treatment periods, 7.5% and 1.6% of patients experienced an AE leading to discontinuation.ConclusionCariprazine was not superior to placebo in the prevention of relapses in this study. Relapse rates were unusually low in the placebo group. Cariprazine was well-tolerated.