Cariprazine is a potent D3/D2 partial agonist with preferential binding to D3 receptors.

To evaluate the efficacy and safety of cariprazine versus placebo in acute exacerbation of schizophrenia.

A multinational, multicenter, double-blind, randomized, placebo- and active-controlled, fixed-dose trial in patients aged 18–60 years with DSM-IV-TR-defined schizophrenia, current psychotic episode < 2 weeks, and PANSS total score between 80 and 120. After 1-week washout, patients received 6-weeks treatment (cariprazine 1.5, 3.0, or 4.5 mg/d, risperidone 4.0 mg/d, or placebo) and 2-week safety follow-up. Risperidone was used to assess assay sensitivity. Primary and secondary efficacy: baseline to Week 6 change (LOCF) in PANSS total and CGI-S scores, respectively. Safety: adverse events (AEs), vital signs, laboratory measures, extrapyramidal symptom (EPS) scales.

Of 732 randomized patients, 64% completed the study. Mean baseline PANSS (98) and CGI-S scores (4.8) were similar across groups. PANSS total score improvement at Week 6 was statistically significant versus placebo for cariprazine 1.5 mg/d, 3.0 mg/d, and 4.5 mg/d (placebo-adjusted improvements: −7.5, −8.9, −10.4, respectively; P < .001; LOCF) and risperidone (−15.0, P < .001, LOCF); significant improvement on CGI-S was demonstrated for all active treatments (P < .05). The most common cariprazine AEs were insomnia, EPS, akathisia, sedation, nausea, dizziness, and constipation. AE discontinuation rates were 15% for placebo, 10%, 5% and 8% for cariprazine 1.5, 3.0, and 4.5 mg/d, respectively, and 9% for risperidone 4.0 mg/d.

Cariprazine significantly improved PANSS and CGI-S scores versus placebo in acute exacerbation of schizophrenia and was generally well tolerated.