Danoprevir

A potent, highly selective, orally available, peptidomimetic HCV NS3/4A protease inhibitor with IC50 of 0.2-0.4 nM (GT1a, 1b, 4, 5 and 6), 1.6 nM (GT2b) ; shows favorable potency profile against multiple HCV genotypes 1–6 and key mutants (replicon GT1b, EC50=1.6 nM) .HCV Infection Approved (In Vitro) :In Huh7.5 cells transfected with chimeric recombinant virus, Danoprevir (ITMN-191) shows antiviral inhibition effects against HCV genotypes 1, 4 and 6 with IC50 of 2-3 nM, which are >100-fold lower than genotypes 2/3/5 (280-750 nM) .Danoprevir (ITMN-191) inhibits the reference genotype 1 NS3/4A protease half-maximally, but a high dose of Danoprevir (ITMN-191) (10 μM) shows no appreciably inhibition in a panel of 79 proteases, ion channels, transporters, and cell surface receptors. Danoprevir (ITMN-191) remains bound to and inhibits NS3/4A for more than 5 hours after its initial association. Danoprevir (ITMN-191) (45 nM) eliminates a patient-derived HCV genotype 1b replicon from hepatocyte-derived Huh7 cells with an EC50 of 1.8 nM.In HCV subgenomic replicon cell lines containing the individual mutations, V36M, R109K, and V170A substitutions confer little or no resistance to Danoprevir (ITMN-191), but the R155K substitution confers a high level (62-fold increase) of resistance to Danoprevir. (In Vivo) :Danoprevir (ITMN-191) (30 mg/kg, p.o.) administered to rats or monkeys shows that its concentrations in liver 12 hours after dosing exceed the Danoprevir concentration required to eliminate replicon RNA from cells.