Pharmacokinetics, Safety, and Tolerability of Cariprazine in Pediatric Patients with Bipolar I Disorder or Schizophrenia.

<b><i>Objective:</i></b> Cariprazine is a dopamine D₃-preferring D₃/D₂ and serotonin 5-HT_1A receptor partial agonist approved to treat adults with schizophrenia and manic/mixed or depressive episodes associated with bipolar I disorder. This sequential-cohort, dose-escalation study was the first to evaluate the pharmacokinetic, safety, and tolerability profile of cariprazine and its two major active metabolites, desmethyl-cariprazine (DCAR) and didesmethyl-cariprazine (DDCAR), in pediatric patients with schizophrenia or bipolar I disorder. <b><i>Methods:</i></b> This phase I open-label study enrolled patients with schizophrenia (13-17 years of age) or bipolar I disorder (10-17 years of age). Patients met the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for schizophrenia or bipolar I disorder and had Positive and Negative Syndrome Scale (PANSS) total scores ≥70 or Young Mania Rating Scale (YMRS) total scores ≥20. Patients were assigned to one of four treatment groups to receive 6 weeks of cariprazine treatment through slow titration to 1.5, 3, or 4.5 mg/d or fast titration to 4.5 mg/d. Pharmacokinetics, adverse events (AEs), and various safety parameters were analyzed. Efficacy was evaluated as an exploratory outcome. <b><i>Results:</i></b> A total of 50 participants were enrolled. Based on mean trough levels, steady state appeared to be reached within 1-2 weeks for cariprazine and DCAR and within 4-5 weeks for DDCAR. Systemic exposure of cariprazine, DCAR, and DDCAR generally increased approximately in proportion to the increases in dose from 1.5 to 4.5 mg/d. The most frequent treatment-related, treatment-emergent AEs included sedation, parkinsonism, tremor, dystonia, and blurred vision. Improvements from baseline on the PANSS and YMRS were observed throughout treatment. <b><i>Conclusion:</i></b> In this first investigation of cariprazine in a pediatric population with schizophrenia or bipolar disorder, pharmacokinetic parameters were consistent with those observed in adults. Cariprazine appeared to be safe and tolerable in children and adolescents.