To examine the effect of cariprazine, a dopamine D3/D2 receptor partial agonist with preferential binding to D3 receptors, on predominant negative symptoms of schizophrenia.

Subjects with schizophrenia and PANSS factor score for negative symptoms (PANSS-FSNS) ≥ 24 and no pseudospecific factors (e.g. extrapyramidal symptoms, depression) were randomized to cariprazine 4.5 mg/d (dose range: 3-6 mg/d) or risperidone 4 mg/d (dose range: 3-6 mg/d) for 6 months.

Four hundred and sixty-one patients were randomized 1:1 to double-blind risperidone (n = 231) or cariprazine (n = 230) treatment. Change from Baseline (CfB) at week 26 in the primary parameter, PANSS-FSNS, was larger in the cariprazine group than in the risperidone group (LSMD = −1.47; 95% CI: [−2.39, −0.53]; P = 0.002) significant from week 14 onwards. CfB at week 26 in the functional parameter, Personal and Social Performance (PSP) total score, showed similarly greater improvement with cariprazine than risperidone (LSMD = 4.63; 95% CI: [2.71, 6.56]; P < 0.001) significant from week 10 onward. Statistically significant differences in favor of cariprazine at week 26 were shown in the PSP areas of self-care, socially useful activities and personal and social relationships. Most patients tolerated the study treatment well, as reflected by low discontinuation rates due to adverse events (AEs). Adverse event profiles of cariprazine and risperidone were similar. The most common AEs during study treatment were insomnia (10.0%), and headache (10.4%), both in the risperidone group.

26-week cariprazine treatment, given as antipsychotic monotherapy, was significantly more effective on negative symptoms and on functioning than risperidone in patients with predominant negative symptoms of schizophrenia.

The authors have not supplied their declaration of competing interest.