1. Inhibition of catechol-O-methyltransferase in the cynomolgus monkey by opicapone after acute and repeated administration
- Author
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Shintaro Mizote, Patrício Soares-da-Silva, Takashi Kitajima, Takeo Umemura, Maria João Bonifácio, Makoto Tanaka, Kazuhiro Yoneda, and Paul Moser
- Subjects
0301 basic medicine ,Erythrocytes ,Time Factors ,Drug Evaluation, Preclinical ,Administration, Oral ,Biological Availability ,Pharmacology ,COMT inhibitor ,Catechol O-Methyltransferase ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Random Allocation ,0302 clinical medicine ,Pharmacokinetics ,Medicine ,Animals ,Oxadiazoles ,Catechol-O-methyl transferase ,Cross-Over Studies ,Dose-Response Relationship, Drug ,business.industry ,Catechol O-Methyltransferase Inhibitors ,Effective dose (pharmacology) ,Crossover study ,Bioavailability ,Dose–response relationship ,Macaca fascicularis ,030104 developmental biology ,chemistry ,Pharmacodynamics ,Female ,business ,030217 neurology & neurosurgery - Abstract
Introduction The aim of the study was to clarify the dose response for inhibition of catechol-O-methyltransferase (COMT) by opicapone, a third generation COMT inhibitor, after acute and repeated administration to the cynomolgus monkey with pharmacokinetic evaluation at the higher dose. Methods Three cynomolgus monkeys were used in the study. In the first experiment, COMT inhibition was evaluated over 24 h after the first and at 24 h after the last of 14 daily oral administrations of vehicle, 1, 10 and 100 mg/kg opicapone using a crossover design. In the second experiment, the effect of the maximally effective dose, 100 mg/kg, was retested under the same conditions with additional monitoring of plasma opicapone levels to explore the relationship between pharmacokinetics and pharmacodynamics. Results Opicapone dose-dependently inhibited COMT activity, significantly so at 10 and 100 mg/kg. Maximal inhibition was 13.1%, 76.4% and 93.2% at 1, 10 and 100 mg/kg respectively, and COMT remained significantly inhibited at 24 h after 10 and 100 mg/kg (42.6% and 60.2% respectively). Following repeated administration of opicapone residual COMT inhibition at 24 h was 15–25% greater at all doses. In contrast to its pharmacodynamic effect, opicapone was rapidly absorbed and eliminated, with no accumulation in plasma following repeated administration. Conclusion Opicapone showed sustained and dose-dependent COMT inhibition despite being rapidly eliminated from plasma and with no evidence for accumulation in plasma after 14 days administration. Opicapone fills the unmet need for a compound with sustained COMT inhibition which will improve levodopa bioavailability in patients with Parkinson's disease.
- Published
- 2018