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 the afflicted individuals do not adequately benefit from treatment, i.e. treatment resistant. The antipsychotic clozapine is believed to be more efficacious than other antipsychotics and therefore used routinely in treatment-resistant schizophrenia despite major side effects. However, according to the current state of science, the superiority of clozapine over other atypical antipsychotics, which have a significantly better side effect profile, has not been reliably demonstrated. In order to clarify whether the use of clozapine in treatment-resistant schizophrenia is justified, we will conduct a systematic review in which we search for all randomized controlled studies comparing clozapine to other atypical antipsychotics in participants with treatment-resistant schizophrenia. Of these studies we will request the individual patient data (IPD) and analyse it in an IPD meta-analysis. The aim of this project is to show 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