Efficacy and safety of aripiprazole once-monthly in Asian patients with schizophrenia: a multicenter, randomized, double-blind, non-inferiority study versus oral aripiprazole.

Objective: This study was designed to evaluate efficacy and safety of aripiprazole once-monthly (AOM) by verifying non-inferiority of AOM to oral aripiprazole in Asian patients with schizophrenia.

Method: The study consisted of a screening phase and three phases: an oral conversion phase (≤12weeks), an oral stabilization phase (≤12weeks) and a 52-week double-blind phase. Patients meeting stabilization criteria for 4weeks during the oral stabilization phase were randomly assigned (1:1) to AOM (400mg) or oral aripiprazole (6-24mg/day). The primary endpoint was Kaplan-Meier estimated rate of non-exacerbation of psychotic symptoms/non-relapse at Week 26.

Results: A total of 724 patients were screened, and 502 patients entered the oral stabilization phase. Of 455 patients randomized in the double-blind phase, 228 received AOM and 227 received oral aripiprazole. The non-exacerbation of psychotic symptoms/non-relapse rates at Week 26 were 95.0% (AOM) and 94.7% (oral aripiprazole) and the difference was 0.3% (95% CI: -3.9,4.5), thus non-inferiority of AOM compared to oral aripiprazole with respect to non-exacerbation of psychotic symptoms/non-relapse rate was shown with a margin of -3.9% which is well above the pre-defined non-inferiority limit (-15%). The proportions of patients meeting exacerbation of psychotic symptoms/relapse criteria and stabilization of psychotic symptoms/maintenance criteria were 6.6% and 92.5% in both groups. Discontinuation rates due to all reasons were 25.9% (AOM) and 33.5% (oral aripiprazole). AOM was well tolerated as well as oral aripiprazole.

Conclusions: Non-inferiority of AOM to oral aripiprazole was established. AOM is efficacious in maintenance treatment of stabilized schizophrenia, with comparable efficacy and tolerability to oral aripiprazole.

Clinical Trials Registration: JapicCTI-101175.