Efficacy and Safety of the 3-Month Formulation of Paliperidone Palmitate vs Placebo for Relapse Prevention of Schizophrenia

Treatment nonadherence and relapse are common problems in patients with schizophrenia.The long-acting 3-month formulation of paliperidone palmitate, owing to its extended elimination half-life, may offer a valuable therapeutic option for these patients.OBJECTIVE To evaluate the efficacy and safety of the 3-month formulation of paliperidone palmitate vs placebo in delaying time to relapse of schizophrenia symptoms.DESIGN, SETTING, AND PARTICIPANTS This randomized, multicenter trial conducted from April 26, 2012, through April 9, 2014, in 8 countries consisted of 4 phases: 3-week screening phase, flexible-dose 17-week open-label transition phase, 12-week open-label maintenance phase, and open-ended double-blind (DB) phase.Of the 506 patients enrolled (aged 18-70 years; DSM-IV-TR diagnosis of schizophrenia), 305 were randomized to 3-month paliperidone palmitate (n = 160) or placebo (n = 145) in the DB phase.INTERVENTIONS Patients received once-monthly doses of the 1-month formulation of paliperidone palmitate (50, 75, 100, or 150 mg eq) during the transition phase, followed by a single dose of the 3-month formulation (3.5 times the stabilized dose of once-monthly paliperidone palmitate) during the maintenance phase.Stabilized patients were randomized to receive either a fixed dose of 3-month paliperidone palmitate (175, 263, 350, or 525 mg eq) or placebo once every 3 months during the DB phase.MAIN OUTCOMES AND MEASURES Time from randomization to the first relapse event (time to relapse) in the DB phase. RESULTSIn the interim analysis, time to first relapse was significantly different in favor of the paliperidone palmitate group vs the placebo group (hazard ratio = 3.45; 95% CI, 1.73-6.88;P < .001);median time to relapse was 274 days for placebo but not estimable for 3-month paliperidone palmitate.An independent data monitoring committee recommended early study termination due to efficacy.In the DB phase, 183 of 305 patients (62% with 3-month paliperidone palmitate; 58% with placebo) had at least 1 treatment-emergent adverse event; those noted more frequently in the group receiving paliperidone palmitate than in the placebo group were headache (9% vs 4%), weight increased (9% vs 3%), nasopharyngitis (6% vs 1%), and akathisia (4% vs 1%). CONCLUSIONS AND RELEVANCECompared with placebo, the 3-month formulation of paliperidone palmitate administered 4 times yearly significantly delayed time to relapse in patients with schizophrenia.The 3-month formulation was generally tolerable and has a safety profile consistent with other marketed paliperidone formulations.