Table 5.

Characterization of gt 1b variants identified in the triple selection using transient replication assays

Selection condition	Varianta			Fold resistanceb			Replication efficiency relative to WT level
	NS3	NS5A	NS5B	Asunaprevir (ASV)	Daclatasvir (DCV)	BMS-791325
10× or 15× triplec	Q80R-R155Q	R30Q-L31M	P495A	30–93	5–15	17–22	0.02–0.1
	Q80R-R155Q	R30Q-L31M-Y93H	P495A	86–99	>500	8–22	0.01
Site-directed mutant	Q41R	—	—	4	1	1	1.0–1.4
Site-directed mutant	Q80R	—	—	4–5	1	1	0.5–1.0
Site-directed mutant	Q41R-Q80R	—	—	7–12	1	1	1.0–1.2
Site-directed mutant	Q80R-R155Q	—	—	42–73	1	1	0.5–1.0

^aReplicons containing a specific substitution(s) identified from selections were tested for resistance and replication fitness. Major selected variant constructs are in bold font. Site-directed mutants were not selected but were generated as controls in the WT backbone to assess impact on phenotype. For each selection condition, each row represents a unique variant including any linked mutations. —, WT sequence.

^bFold resistance was determined by dividing the mutant HCV replicon EC₅₀ by the WT replicon EC₅₀. WT EC₅₀s were 2.0 ± 0.6, 0.002 ± 0.001, and 8.3 ± 2.2 nM for ASV, DCV, and BMS-791325, respectively. Results represent the range of values determined from two or three independent experiments.

^cSelection of viable triple mutants in gt 1b required sequential passage in gradually increasing concentrations of inhibitor as detailed in Materials and Methods.