Paliperidone Palmitate Once-Monthly Reduces Risk of Relapse of Psychotic, Depressive, and Manic Symptoms and Maintains Functioning in a Double-Blind, Randomized Study of Schizoaffective Disorder

OBJECTIVE: Schizoaffective disorder is a complex illness for which optimal treatment is not well established. Results of the first controlled, relapse-prevention study of paliperidone palmitate once-monthly injectable (paliperidone monthly) in schizoaffective disorder are presented. METHOD: The study was conducted between September 20, 2010, and October 22, 2013. Patients with schizoaffective disorder (confirmed by the Structured Clinical Interview for DSM-IV Axis I Disorders) experiencing acute exacerbation of psychotic and depressive/manic symptoms were stabilized with paliperidone monthly as monotherapy or as adjunctive therapy to mood stabilizers or antidepressants and randomly assigned (1:1) to paliperidone monthly or placebo in a 15-month, double-blind, relapse-prevention phase. Randomization was stratified by administration as monotherapy or adjunctive therapy and by study center. The primary endpoint was time to relapse. RESULTS: 334 patients were evaluated. Paliperidone monthly significantly delayed time to relapse for psychotic, depressive, and manic symptoms compared with placebo (P < .001, log-rank test). Relapse risk was 2.49 times greater for placebo (hazard ratio = 2.49; 95% CI, 1.55 to 3.99; P < .001, Cox proportional hazards model). Overall relapse rates were 33.5% for placebo and 15.2% for paliperidone monthly. For monotherapy, relapse risk was 3.38 times greater with placebo (P = .002), and for adjunctive treatment it was 2.03 times greater with placebo (P = .021). Paliperidone monthly was superior to placebo in maintaining functioning as measured by the Personal and Social Performance scale (P = .014, mixed-model repeated-measures analysis). The most common adverse events (placebo, paliperidone monthly) were increased weight (4.7%, 8.5%), insomnia (7.1%, 4.9%), schizoaffective disorder (5.9%, 3.0%), headache (3.5%, 5.5%), and nasopharyngitis (3.5%, 5.5%). Incidence of any extrapyramidal-related adverse event was 7.1% for placebo and 8.5% for paliperidone monthly. CONCLUSIONS: Paliperidone monthly as monotherapy or adjunctive therapy significantly delayed psychotic, depressive, and/or manic relapses; reduced their risk; and better maintained functioning in patients with schizoaffective disorder. Results support the value of maintenance treatment with paliperidone monthly in schizoaffective disorder. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01193153.