Efficacy and safety of cariprazine in bipolar I depression: A double-blind, placebo-controlled phase 3 study

Objective: To assess the efficacy, safety, and tolerability of cariprazine in the treatment of the depressed phase of bipolar I disorder in adults (NCT02670538).

Methods: In this phase 3 double-blind placebo-controlled study, adult patients with bipolar I disorder according to the Diagnostic and Statistical Manual - 5th Edition criteria and a current depressive episode were randomized to placebo (n = 167), cariprazine 1.5 mg/day (n = 168) or cariprazine 3.0 mg/day (n = 158). Efficacy parameters were changes in the Montgomery-Åsberg Depression Rating Scale (MADRS) total scores (primary) and Clinical Global Impressions - Severity (CGI-S) scores (secondary) from baseline to Week 6 compared to placebo. A mixed-model for repeated measures was used to estimate the least-squares mean differences (LSMD); P-values were adjusted for multiplicity. Adverse events (AEs), laboratory results, vital signs, and suicide risk were monitored.

Results: Cariprazine 1.5 mg/day significantly reduced depressive symptoms on the primary (MADRS LSMD = -2.5; adjusted P = .0417) and secondary (CGI-S LSMD = -0.3; adjusted P = .0417) efficacy parameters vs placebo; differences were not statistically significant for cariprazine 3.0 mg/day. Common treatment-emergent AEs (≥5% in either cariprazine group and at least twice the incidence of placebo) were akathisia, restlessness, nausea, and fatigue. Mean metabolic parameter changes were low and generally comparable among groups; mean weight increases were ≤0.5 kg for all groups.

Conclusions: Cariprazine 1.5 mg/day significantly reduced depressive symptoms in adults with bipolar I depression compared to placebo, but differences were not significant for cariprazine 3.0 mg/day. The safety and tolerability profiles were similar to previous studies of cariprazine.