The efficacy of cariprazine in chronic schizophrenia – post hoc analyses of phase II/III clinical trials

Abstract

Introduction Chronic schizophrenia patients are experiencing persistent and severe illness for more than 15-20 years and are usually suffering from long-term negative symptoms. Cariprazine, a novel D3-D2 partial agonist has been proven to be effective in the treatment of acute schizophrenia, however its ability to treat chronic patients has not been assessed yet. Objectives The primary aim of the present post-hoc analysis is to assess the efficacy of cariprazine in treating patients with chronic schizophrenia (late-stage and residual schizophrenia patients). Methods Data from 3 phase II/III 6-week, randomized, double-blind, placebo-controlled trials with similar design in patients with acute exacerbation of schizophrenia were pooled and patients with more than 15 years of schizophrenia were analysed (late-stage patients). Furthermore, schizophrenia patients experiencing predominantly negative symptoms from a 26-week, randomized, double-blind, active-controlled, fixed-flexible-dose trial with an ICD-10 code of F20.5 were analysed post-hoc (residual patients). Results Altogether, 414 late stage (286 cariprazine and 128 placebo) and 35 residual (23 cariprazine and 12 risperidone) patients were identified. The pooled analysis evaluating mean change from baseline to week 6 in the PANSS total score indicated statistically significant difference in favour of cariprazine in the late stage (LSMD -6.7, p<0.01) subpopulation compared to placebo. The mean change from baseline in patients with residual schizophrenia in the cariprazine arm was -9.6 on the PANSS-FSNS scale, while -7.9 in the risperidone arm. Conclusions Based on the results, it seems that cariprazine might be a good treatment option for patients with chronic schizophrenia. Nonetheless, further studies are needed to confirm this. Disclosure I am an employee of Gedeon Richter Plc.