Faldaprevir sodium is a potent, orally active and selective noncovalent inhibitor of NS3/4A protease of HCV (hepatitis C virus) genotypes 1a and 1b, with K i values of 2.6 and 2.0 nM, respectively. Faldaprevir sodium inhibits HCV RNA replication, with EC 50 values of 6.5 and 3.1 nM, respectively. Faldaprevir sodium has potent antiviral activity against chronic HCV infection.