Efficacy and tolerability of blonanserin in schizophrenia: A systematic review and meta-analysis of randomized controlled trials

Background: Blonanserin is approved for treating schizophrenia in Japan, South Korea, India, and China. We aimed to synthesize the efficacy and tolerability of blonanserin compared to other antipsychotics. Methods: A systematic review and pairwise meta-analysis were conducted using the Cochrane Schizophrenia Group's study-based trial register until January 24, 2024. We included open and blinded randomized controlled trials (RCTs) involving schizophrenia patients, with studies lasting at least 3 weeks. Primary outcomes focused on overall schizophrenia symptoms using rating scales and relapse rates. Secondary outcomes included symptom subtypes, treatment response, dropout rates, quality of life, and side effects, analyzed using standardized mean difference (SMD), mean difference (MD), and risk ratio (RR) with 95 % confidence intervals (CIs). The review protocol was published in Open Science Framework (https://osf.io/e7jfa/). Results: Fourteen acute-phase studies with 2697 participants compared blonanserin to olanzapine, haloperidol, risperidone, paliperidone, aripiprazole, amisulpride, and placebo. Blonanserin showed greater efficacy than placebo (SMD =-0.47, 95 % CI:-0.66 to-0.27) and similar efficacy to other antipsychotics in reducing schizophrenia overall symptoms. No data on the number of participants who experienced relapse with blonanserin was available in the single maintenance-phase study. There were also no clear differences between antipsychotics in most secondary efficacy outcomes, but blonanserin produced less prolactin and weight increase but more akathisia and tremor than risperidone, and less prolactin increase, anticholinergic and extrapyramidal side-effects than haloperidol. Conclusion: Our study suggests that differences in efficacy between blonanserin and other antipsychotics are small and that blonanserin has a different tolerability profile than haloperidol and risperidone.