RO-9187 suppresses 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 or 2′-C-methyl nucleosides. RO-9187 is excellent substrates for deoxycytidine kinase and is phosphorylated with efficiencies up to 3-fold higher than deoxycytidine. The formation of RO-9187-TP increased in a time- and dose-dependent manner [1].

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 RO-9187 (1.4 and 26 μM ) 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 RO-9187 (2000 mg/kg/day)[1].