Randomized, double‐blind, 6‐week non‐inferiority study of lurasidone and risperidone for the treatment of schizophrenia

AIM: The aim of the present study was to evaluate the efficacy and safety of lurasidone for the treatment of Chinese schizophrenic patients. METHODS: Hospitalized schizophrenia patients aged 18–65 were randomized to 6 weeks of double‐blind, double‐dummy, flexible‐dose treatment with lurasidone (40 or 80 mg/day) or risperidone (2, 4 or 6 mg/day). Efficacy was evaluated using a non‐inferiority comparison of lurasidone relative to risperidone based on week 6 change in the Positive and Negative Syndrome Scale (PANSS) total score. Safety assessments included adverse events, clinical laboratory measures, and electrocardiograms. RESULTS: Four hundred and forty‐four patients were screened to obtain an intent‐to‐treat sample of 384 patients, of whom 54 patients discontinued treatment prior to 6 weeks. Lurasidone met the criteria for non‐inferiority versus risperidone on the PANSS total score. Adjusted mean (SE) change at week 6 on the PANSS total score was −31.2 (1.0) and −34.9 (1.0) in the lurasidone and risperidone group, respectively. The mean difference score was 3.7, and the upper boundary of the 95%‐confidence interval (1.0–6.3) was less than the prespecified margin of 7.0. No clinically meaningful between‐treatment group differences were evident on secondary efficacy measures, including PANSS positive, PANSS negative, Clinical Global Impression scale – Severity, and Calgary Depression Scale for Schizophrenia scales. The incidence of adverse events was lower for lurasidone vs risperidone for extrapyramidal symptoms (17.0% vs 38.2%), akathisia (7.2% vs 13.6%), prolactin increase (3.1% vs 14.1%), and weight increase (0.5% vs 5.2%). CONCLUSION: Lurasidone was found to be non‐inferior to risperidone on the primary endpoint with minimal effects on weight, metabolic parameters, or prolactin levels.