Efficacy of cariprazine on negative symptoms in patients with acute schizophrenia: A post hoc analysis of pooled data

Although currently approved antipsychotics exert efficacy on positive symptoms of schizophrenia, treatments for negative symptoms remain a major unmet need. Post hoc analyses were used to investigate the possible efficacy of cariprazine in patients with moderate/severe negative symptoms of schizophrenia and no predominance of positive symptoms. Data were pooled from 2 randomized, double-blind, placebo- and active-controlled cariprazine studies in patients with acute schizophrenia (NCT00694707, NCT01104766). Analyses included data from a subset of patients with a Positive and Negative Syndrome Scale factor score for negative symptoms (PANSS-FSNS) ≥24, PANSS factor score for positive symptoms (PANSS-FSPS) ≤19, and scores of ≥4 on ≥2 of 3 PANSS items (blunted affect [N1], passive/apathetic social withdrawal [N4], lack of spontaneity/flow of conversation [N6]). Changes from baseline to week 6 in PANSS-FSNS were evaluated in the following treatment groups: placebo (n = 79), cariprazine 1.5-3 (n = 94) and 4.5-6 mg/d (n = 66), risperidone 4 mg/d (n = 34), or aripiprazole 10 mg/d (n = 44). Significant differences were observed versus placebo for cariprazine (1.5-3 mg/d, P = .0179; 4.5-6 mg/d, P = .0002) and risperidone (P = .0149), but not aripiprazole (P = .3265), and versus aripiprazole for cariprazine 4.5-6 mg/d (P = .0197). After adjusting for positive symptom changes, differences versus placebo remained statistically significant for cariprazine (1.5-3 mg/d, P = .0322; 4.5-6 mg/d, P = .0038) but not for risperidone (P = .2204). PANSS-FSNS response (≥20% reduction from baseline) rates were significantly higher with cariprazine (1.5-3 mg/d = 54.3%, P = .0194; 4.5-6 mg/d = 69.7%, P = .0001) than placebo (35.4%). In patients with acute schizophrenia and moderate/severe negative symptoms, cariprazine was associated with significantly greater improvement in negative symptoms compared with placebo and aripiprazole, warranting further exploration of the efficacy of cariprazine on negative symptoms.