An orally bioavailable and potent inhibitor of HCV NS5A; reduces HCV replication in stable replicon cell lines with EC50 values of 0.82 to 19.3 pM against genotypes 1a, 1b, 2a, 2b, 3a, 4a, and 5a and an EC50 value of 366 pM for genotype 6a; inhibits HCV replication against subgenomic replicons of clinical isolates of genotype 1a to 6a (EC50s = 0.1 to 68 pM) ,