Sofosbuvir

Sofosbuvir (GS-7977) is an HCV RNA replication inhibitor with an EC₅₀ of 92 nM^[1]. IC50 & Target:EC50: 92±5 nM (HCV)^[1] In Vitro: When cathepsin A (CatA) is incubated with PSI-7977 or Sofosbuvir (PSI-7977) for 150 min, ~18-fold more PSI-352707 is formed when Sofosbuvir (PSI-7977) is the substrate compared with PSI-7976. Moreover, the catalytic efficiency for Sofosbuvir (PSI-7977) with CatA is ~30-fold higher than that for PSI-7976^[1]. The genotype coverage of Sofosbuvir (PSI-7977) by using GT 1b (Con1)-, 1a (H77)-, and 2a (JFH-1)-derived replicons and GT 1b chimeric replicons containing the NS5B region from the J6 GT 2a isolate and from GT 2b and GT 3a patient isolates is evaluated, Sofosbuvir (PSI-7977) inhibits the replication of these replicons with similar EC₅₀s (between 16 and 48 nM), and is especially active against the chimeric replicon containing the J6 NS5B (EC₅₀=4.7 nM). Sofosbuvir (PSI-7977) inhibits clone A (GT 1b) wild-type and S282T replicons with EC₉₀ values of 0.42 and 7.8 μM, respectively^[2]. In the clone A replicon assay, Sofosbuvir (PSI-7977) produces anti-HCV activity with EC₉₀ values 0.42 μM^[3].