876708-03-1

IC50: 171 nM (HCV)

RO-9187 is excellent substrates for deoxycytidine kinase and is phosphorylated with efficiencies up to 3-fold higher than deoxycytidine. RO-9187 inhibits RNA synthesis by HCV polymerases from either HCV genotypes 1a and 1b or containing S96T or S282T point mutations with similar potencies, suggesting no cross-resistance with either R1479 (4′-azidocytidine) or 2′-C-methyl nucleosides. The formation of RO-9187-TP increased in a time- and dose-dependent manner. The maximal triphosphate concentration at 24 h is 87 pmol/106 cells with half-maximal triphosphate formation achieved at 12 μM RO-9187.

Plasma exposures of RO-9187 in rats increase in a dose-dependent manner between 10 and 2000 mg/kg after oral dosing. Plasma concentrations of 1.4 and 26 μM (390 and 7454 ng/mL) are achieved in rats and dogs at the 10 mg/kg dose level, respectively. Plasma concentrations up to 57 μM are achieved in rats dosed with 2000 mg/kg/day.