Pimavanserin (ACP-103), marketed under the trade name Nuplazid, is a drug developed by Acadia Pharmaceuticals which acts as an inverse agonist on the serotonin receptor subtype 5-HT2A, with 40x selectivity over 5-HT2C, and no significant affinity or activity at 5-HT2B or dopamine receptors. As of September 3, 2009, pimavanserin has not met expectations for Phase III clinical trials for the treatment of Parkinson's disease psychosis, and is in Phase II trials for adjunctive treatment of schizophrenia alongside an antipsychotic medication. It is expected to improve the effectiveness and side effect profile of antipsychotics. The results of a clinical trial examining the efficacy, tolerability and safety of adjunctive pimavanserin to risperidone and haloperidol were published in November 2012 and the results showed that pimavanserin potentiated the antipsychotic effects of subtherapeutic doses of risperidone and improve the tolerability of haloperidol treatment by reducing the incidence of extrapyramidal symptoms. On September 2, 2014, the United States Food and Drug administration granted Breakthrough Therapy status to Acadia's New Drug Application for pimavanserin.
Investigated for use/treatment in neurologic disorders, parkinson's disease, psychosis, schizophrenia and schizoaffective disorders, and sleep disorders.
Mechanism of action
ACP-103 reduces haloperidol-induced akathisia, a debilitating extrapyramidal side effect (EPS), in patients with schizophrenia. ACP-103 is a 5-HT2A inverse agonist, to reduce the side effects associated with antipsychotic drug treatment with haloperidol. ACP-103 reduced both the motor disturbances and hyperprolactinemia, a condition of elevated prolactin secretion, caused by haloperidol treatment.
The therapeutic efficacy of Rotigotine can be decreased when used in combination with Pimavanserin.
Nordstrom AL, Mansson M, Jovanovic H, Karlsson P, Halldin C, Farde L, Vanover KE, Hacksell U, Brann MR, Davis RE, Weiner DM: PET analysis of the 5-HT2A receptor inverse agonist ACP-103 in human brain. Int J Neuropsychopharmacol. 2008 Mar;11(2):163-71. Epub 2007 Aug 21. [PubMed:17708779 ]
G-protein coupled receptor for 5-hydroxytryptamine (serotonin). Also functions as a receptor for various drugs and psychoactive substances, including mescaline, psilocybin, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and lysergic acid diethylamide (LSD). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates...