Clozapine versus second-generation antipsychotic drugs in patients with treatment-resistant schizophrenia

Individual-patient-data (IPD) meta-analysis of the efficacy of clozapine versus second-generation antipsychotic drugs in patients with treatment-resistant schizophrenia

The project is funded by the German Federal Ministry of Education and Research (BMBF) (FKZ 01KG2015).

Schizophrenia is a serious mental disorder, and antipsychotics are the treatment of choice. However, up to a third of affected individuals do not adequately benefit from treatment and are considered treatment-resistant. The antipsychotic clozapine is believed to be more efficacious than other antipsychotics and is therefore routinely used in treatment-resistant schizophrenia despite major side effects. However, current research has not reliably demonstrated the superiority of clozapine over other atypical antipsychotics, which have a significantly better side effect profile.

To determine whether the use of clozapine in treatment-resistant schizophrenia is justified, we will conduct a systematic review by searching for all randomized controlled trials comparing clozapine to other atypical antipsychotics in participants with treatment-resistant schizophrenia. For these studies, we will request the individual patient data (IPD) and analyze it in an IPD meta-analysis. The aim of this project is to establish whether clozapine is more efficacious than other atypical antipsychotics and whether efficacy is associated with patient characteristics (e.g., disease severity, gender, or age) or treatment characteristics (e.g., type and dose of antipsychotic).

This systematic review is registered at PROSPERO (Link).

Conduct of the project: Dr. Johannes Schneider-Thoma; contact: joh.schneider@tum.de

Supervision: Professor Stefan Leucht