Long-term cariprazine treatment for the prevention of relapse in patients with schizophrenia: A randomized, double-blind, placebo-controlled trial

Cariprazine, a dopamine D3/D2 receptor partial agonist with preference for D3 receptors, has demonstrated efficacy in randomized controlled trials in schizophrenia. This multinational, randomized, double-blind, placebo-controlled, parallel-group study evaluated the efficacy, safety, and tolerability of cariprazine for relapse prevention in adults with schizophrenia; total study duration was up to 97weeks. Schizophrenia symptoms were treated/stabilized with cariprazine 3-9mg/d during 20-week open-label treatment consisting of an 8-week, flexible-dose run-in phase and a 12-week fixed-dose stabilization phase. Stable patients who completed open-label treatment could be randomized to continued cariprazine (3, 6, or 9mg/d) or placebo for double-blind treatment (up to 72weeks). The primary efficacy parameter was time to relapse (worsening of symptom scores, psychiatric hospitalization, aggressive/violent behavior, or suicidal risk); clinical measures were implemented to ensure safety in case of impending relapse. A total of 264/765 patients completed open-label treatment; 200 eligible patients were randomized to double-blind placebo (n=99) or cariprazine (n=101). Time to relapse was significantly longer in cariprazine- versus placebo-treated patients (P=.0010, log-rank test). Relapse occurred in 24.8% of cariprazine- and 47.5% of placebo-treated patients (hazard ratio [95% CI]=0.45 [0.28, 0.73]). Akathisia (19.2%), insomnia (14.4%), and headache (12.0%) were reported in ≥10% of patients during open-label treatment; there were no cariprazine adverse events ≥10% during double-blind treatment. Long-term cariprazine treatment was significantly more effective than placebo for relapse prevention in patients with schizophrenia. The long-term safety profile in this study was consistent with the safety profile observed in previous cariprazine clinical trials. ClincalTrials.gov identifier: NCT01412060.