TABLE 6

In vitro activity of NS5A inhibitors against chimeric NS5A GT3b HCV replicons

HCV repliconAmino acid at positions of interest in NS5AMean EC50 ± SD (pM)e
PibrentasvirDaclatasvirVelpatasvir
GT3aa
    Wild typeS24, M28, A30, L31, P32, P58, E92, Y930.65 ± 0.1623.3 ± 7.94.4 ± 0.89
    Wild type (JFH1)0.39 ± 0.0861.4 ± 22.51.84 ± 0.31
GT3bb
    Wild-typeS24, M28, K30, M31, P32, P58, E92, Y9315.6 ± 1.51,267,333 ± 74,097200,567 ± 41,464
    K30AcS24, M28, A30, M31, P32, P58, E92, Y930.62 ± 0.0435,263 ± 12,276195 ± 43
    M31LcS24, M28, K30, L31, P32, P58, E92, Y932.5 ± 0.5579,300 ± 127,52510,188 ± 1,513
    K30A + M31LcS24, M28, A30, L31, P32, P58, E92, Y930.91 ± 0.12169 ± 19.34.97 ± 1.37
    M31VdS24, M28, K30, V31, P32, P58, E92, Y93365 ± 471,690,667 ± 268,658346,867 ± 119,158
    Y93HS24, M28, K30, M31, P32, P58, E92, H9398,843 ± 35,9012,795,333 ± 677,8561,607,000 ± 659,190
  • a GT3a wild type refers to NS5A-GT3a chimeric replicon in GT1b-Con1 background. This replicon was used to evaluate activity of pibrentasvir as shown in Table 4. The JFH1 wild-type refers to NS5A-GT3a chimeric replicon in a GT2a-JFH1 background.

  • b GT3b wild-type refers to NS5A-GT3b chimeric replicon in the GT2a-JFH1 background; GT3b amino acid substitutions were also generated in this chimeric replicon.

  • c The polymorphism was not detected in patient isolates. Substitutions K30A and/or M31L were constructed to evaluate their potential impact on susceptibility to NS5A inhibitors.

  • d The polymorphism was not detected in patient isolates. Substitution M31V was constructed to match amino acids at positions of interest to those in reference sequence HCV-Tr.

  • e EC50, half-maximal effective concentration; SD, standard deviation.