CARIPRAZINE: NEW DOPAMINE BIASED AGONIST FOR NEUROPSYCHIATRIC DISORDERS

Cariprazine (RGH-188, MP-214, Vraylar (TM)) is a new dopamine receptor ligand developed for the treatment of several neuropsychiatric diseases including schizophrenia and bipolar disorders. Cariprazine displays higher affinity at dopamine D-3 receptors and a similar affinity at D-2 and 5-HT2B receptors. At variance with some atypical antipsychotics, its affinity at 5-HT1A, 5-HT2A and histamine H-1 receptors is modest compared with its three main targets. Cariprazine could correspond to a biased agonist at dopamine receptors, displaying either antagonist or partial agonist properties depending on the signaling pathways linked to D-2/D-3 receptors. The compound crosses the blood-brain barrier, as revealed by positron emission tomography and pharmacokinetic studies in various species. Two main metabolites result mainly from the activity of CYP34A and display properties similar to those of the parent drug. Behavioral data report that cariprazine is efficacious in animal models addressing positive, negative and cognitive symptoms of schizophrenia with no extrapyramidal side effects. In September 2015, the FDA approved the use of cariprazine for the treatment of schizophrenia and type I bipolar disorder. The efficacy of cariprazine in other neuropsychiatric diseases is currently being evaluated in preclinical and clinical studies. Side effects have been observed in humans, including extrapyramidal side effects and akathisia of mild to moderate intensity.