Effectiveness of Lurasidone Vs. Quetiapine XR for Relapse Prevention in Schizophrenia: a 12-month, Double-blind, Noninferiority Study

Objective: To evaluate the relapse prevention efficacy of lurasidone compared with quetiapine XR (QXR) in adults patients with schizophrenia.

Method: This double-blind study evaluated the relapse prevention efficacy of 12 months of flexible-dose treatment with lurasidone (40-160 mg/day) compared with QXR (200-800 mg/day), in outpatients with an acute exacerbation of chronic schizophrenia who had recently completed a 6-week placebo-controlled trial of treatment with either lurasidone or QXR. The primary endpoint, time-to-relapse, was analyzed using a Cox proportional hazards model in this noninferiority trial.

Results: The Kaplan-Meier estimate of the probability of relapse over 12 months was 23.7% for subjects receiving lurasidone vs. 33.6% for QXR. The hazard ratio [95% CI] for probability of relapse was 0.728 [0.410, 1.295] (log-rank p=0.280). Since the upper limit of the hazard ratio (1.295) was smaller than the prespecified noninferiority margin (1.93), noninferiority of lurasidone compared with QXR was demonstrated in this study. The probability of hospitalization at 12 months was lower for the lurasidone group compared with the QXR group (9.8% vs. 23.1%; log-rank p=0.049). A significantly higher proportion of lurasidone subjects achieved remission at study endpoint compared with the QXR group (61.9% vs. 46.3%; p=0.043). Discontinuation rates due to AEs were similar for lurasidone and QXR (7% vs. 5%). Treatment with lurasidone was not associated with clinically significant changes in weight or metabolic parameters.

Conclusions: Twelve months of treatment with lurasidone met noninferiority criteria, and was associated with higher rates of remission, and reduced risk of hospitalization compared with QXR. No clinically significant effects on weight or metabolic parameters were observed during maintenance treatment with lurasidone.