After the first 600-mg dose, mean AT-273 trough concentrations (27.5 ng/ml in NC GT1b-infected subjects, 30.1 ng/ml in NC GT3-infected subjects, and 41.6 ng/ml in subjects with cirrhosis) already exceeded the EC95 of AT-511 in inhibiting replicons containing HCV constructs of clinical isolates (GT1b EC95 of ∼22-ng/ml AT-273 equivalent, GT2 EC95 of ∼12 ng/ml, and GT3 EC95 of ∼18 ng/ml), resulting in very rapid plasma HCV RNA decreases of up to 2.4 log10 IU/ml within the first 24 h of dosing. Here, ITGB3 is linked to Cirrhosis.