In Vitro and In Vivo Isotope Effects with Hepatitis C Protease Inhibitors: Enhanced Plasma Exposure of Deuterated Telaprevir versus Telaprevir in Rats
作者:François Maltais、Young Chun Jung、Minzhang Chen、Jerry Tanoury、Robert B. Perni、Nagraj Mani、Leena Laitinen、Hui Huang、Shengkai Liao、Hongying Gao、Hong Tsao、Eric Block、Chien Ma、Rebecca S. Shawgo、Christopher Town、Christopher L. Brummel、David Howe、S. Pazhanisamy、Scott Raybuck、Mark Namchuk、Youssef L. Bennani
DOI:10.1021/jm901023f
日期:2009.12.24
Telaprevir 2 (VX-950), an inhibitor of the hepatitis C virus (HCVa) NS3-4A protease, is in phase 3 clinical trials. One of the major metabolites of 2 is its P1-(R)-diastereoisomer, 3 (VRT-394), containing an inversion at the chiral center next to the alpha-ketoamide on exchange of a proton with solvent. Compound 3 is approximately 30-fold less active against HCV protease. In an attempt to suppress the epimerization of 2 without losing activity against the HCV protease, the proton at that chiral site was replaced with deuterium (d). The compound 1 (d-telaprevir) is as efficacious as 2 in in vitro inhibition of protease activity and viral replication (replicon) assays. The kinetics of in vitro stability of 1 and 2 in buffered pH solutions and plasma samples, including human plasma, suggest that 1 is significantly more stable than 2. Oral administration (10 mg/kg) in rats resulted in a similar to 13% increase of AUC for 1.