Genotypic and Phenotypic Analyses of Hepatitis C Virus Variants Observed in Clinical Studies of VX-222, a Nonnucleoside NS5B Polymerase Inhibitor

作者：Min Jiang, Eileen Z. Zhang, Andrzej Ardzinski, Ann M. Tigges, Andrew R. Davis, James C. Sullivan, Michelle Nelson, Joan Spanks, Jennifer Dorrian, Olivier Nicolas, Doug J. Bartels, B. Govinda Rao, René Rijnbrand, Tara L. Kieffer · 发表于：Antimicrobial Agents and Chemotherapy · 年份：2014 · DOI：10.1128/aac.03052-14 · 被引用次数：21 · 研究领域：Hepatitis C virus research、HIV/AIDS drug development and treatment、Hepatitis B Virus Studies

VX-222, a thiophene-2-carboxylic acid derivative, is a selective nonnucleoside inhibitor of the hepatitis C virus (HCV) NS5B RNA-dependent RNA polymerase. In phase 1 and 2 clinical studies, VX-222 demonstrated effective antiviral efficacy, with substantial reductions in plasma HCV RNA in patients chronically infected with genotype 1 HCV. To characterize the potential for selection of VX-222-resistant variants in HCV-infected patients, the HCV NS5B gene was sequenced at baseline and during and after 3 days of VX-222 dosing (monotherapy) in a phase 1 study. Variants with the substitutions L419C/I/M/P/S/V, R422K, M423I/T/V, I482L/N/T, A486S/T/V, and V494A were selected during VX-222 dosing, and their levels declined over time after the end of dosing. Phenotypic analysis of these variants was conducted using HCV replicons carrying site-directed mutations. Of the 17 variants, 14 showed reduced susceptibility to VX-222 compared with the wild type, with the L419C/S and R422K variants having higher levels of resistance (>200-fold) than the rest of the variants (6.8- to 76-fold). The M423I and A486S variants remained susceptible to VX-222. The 50% effective concentration (EC50) for the L419P variant could not be obtained due to the poor replication of this replicon. The majority of the variants (15/17) were less fit than the wild type. A subset of the variants, predominately the L419S and R422K variants, were observed when the efficacy and safety of VX-222- and telaprevir-based regime...