[CAS NO. 402957-28-2]  Telaprevir (VX-950)

Telaprevir inhibits the hepatitis C virus NS3-4A serine protease, leading to the block of viral polyprotein processing and subsequently decrease of viral RNA replication, total HCV RNA levels and protein levels in the Con1 (genotype 1b) subgenomic HCV replicon cells in a time- and dose-dependent manner. Telaprevir displays a significant time-dependent increase in inhibitory effect on the replication of HCV RNA with IC50 values of 0.574 μM, 0.488 μM, 0.210 μM and 0.139 μM for 24, 48, 72 and 120 hours incubation, respectively. Telaprevir displays an average IC50 of 0.354 μM and an average IC90 of 0.830 μM, respectively, from three independent experiments using the 48 hours incubation. Telaprevir has no significant cytotoxicity to HCV replicon cells, parental Huh-7 and HepG2 cells after 48 hours incubation. Telaprevir (17.5 μM) completely eradicates HCV RNA from replicon cells after 13 days incubation without rebound after Telaprevir is withdrawn. Telaprevir displays an additive to moderate synergistic effect on reduction of HCV RNA replication and suppression of resistance mutations without significant increase in cytotoxicity when in combination with IFN-α, compared to treatment with each agent alone.