The effectiveness and safety of amisulpride in Chinese patients with schizophrenia who switch from risperidone or olanzapine: a subgroup analysis of the ESCAPE study

INTRODUCTION Second-generation antipsychotics show significant interpatient variability in treatment response and side-effect profiles, and the majority of patients with schizophrenia require multiple treatment changes. This subgroup analysis of the ESCAPE study evaluated the efficacy and safety of amisulpride in Chinese patients with schizophrenia who switched from risperidone or olanzapine. METHODS ESCAPE was a prospective, open-label, multicenter, single-arm Phase IV study in which Chinese patients with an ICD-10 diagnosis of schizophrenia received amisulpride for 8 weeks. This analysis included 109 patients who switched to amisulpride from risperidone (n=68) or olanzapine (n=41) and 59 treatment-naïve patients for reference. The primary effectiveness outcome was a ≥50% decrease in Positive and Negative Syndrome Scale (PANSS) Total score from Baseline to Week 8. The study was registered at ClinicalTrials.gov (NCT01795183). RESULTS Of the patients who switched from risperidone and olanzapine, 77.9% and 56.1% achieved ≥50% reduction in PANSS Total score from Baseline to Week 8 and 57.4% and 46.3% achieved ≥20% reduction in PANSS score from Baseline to Week 2, respectively; these end points were achieved by 66.1% and 61.0% of treatment-naïve patients, respectively. No unexpected adverse events (AEs) were reported. Of the most common AEs, extrapyramidal side effects occurred in 32.4% and 14.6%, blood prolactin increase in 32.4% and 39.0%, and ≥7% increase in body weight in 4.4% and 12% of patients switching from risperidone and olanzapine, respectively. CONCLUSION The results of this subgroup analysis suggest that switching to amisulpride from risperidone and olanzapine is effective and generally well tolerated in Chinese patients with schizophrenia.