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

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 D(3)-D(2) 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.