Study to Assess the Safety, Tolerability, Pharmacokinetics and Antiviral Activity of ABT-267 in HCV Infected Subjects

Blood samples were collected pre-dose (time 0) and at 2, 4, and 6 hours post-dose on Day 1 and pre-dose on Day 2 (ABT-267 monotherapy). The samples were analyzed for ABT-267 using validated analytical methods. Maximum plasma concentration (Cmax; measured in ng/mL) was estimated using noncompartmental analyses.

Blood samples were collected pre-dose (time 0) and at 2, 4, and 6 hours post-dose on Day 1 and pre-dose on Day 2 (ABT-267 monotherapy). The samples were analyzed for ABT-267 using validated analytical methods. Time of maximum plasma concentration (Tmax; measured in hours) was estimated using noncompartmental analyses.

Blood samples were collected pre-dose (time 0) and at 2, 4, and 6 hours post-dose on Day 1 and pre-dose on Day 2 (ABT-267 monotherapy). The samples were analyzed for ABT-267 using validated analytical methods. Area under the plasma concentration-time curve from time 0 to 24 hours (AUC[24]; measured in ng multiplied by hour/mL) was estimated using noncompartmental analyses.

Blood samples were collected pre-dose on Day 2 (prior to second dose of ABT-267 monotherapy) and pre-dose on Day 3 (prior to first dose of combination therapy). The samples were analyzed for ABT-267 using validated analytical methods. Pre-dose plasma concentrations on Day 2 and Day 3 (Ctrough, measured in ng/mL) are reported.

An adverse event was defined as any untoward medical occurrence in a patient or clinical investigation participant administered a pharmaceutical product and that did not necessarily have a causal relationship with this treatment.

The investigator assessed the relationship of each AE to the use of direct-acting antiviral agents (DAAs), and rated the severity of each event as either: Mild: The AE was transient and easily tolerated by the participant; Moderate: The AE caused the participant discomfort and interrupted usual activities; Severe: The AE caused considerable interference with the participant's usual activities and could have been incapacitating or life-threatening.

A serious adverse event was any event that resulted in death, was life-threatening, resulted in hospitalization or prolongation of hospitalization, resulted in a congenital anomaly or persistent or significant disability or was any other important medical event requiring medical or surgical intervention.

The baseline value was the last measurement before the first dose of ABT-267 monotherapy (Day 1). The maximal decrease during monotherapy was the change from baseline to the lowest log10 IU/mL HCV RNA level any time from the first dose of ABT-267 on Day 1 to the last log10 HCV RNA level before the first dose of ABT-267 combination therapy (Study Day 3).

The percentage of participants with sustained virologic response (plasma Hepatitis C virus ribonucleic acid [HCV RNA] level less than the lower limit of quantitation [< LLOQ]) 12 and 24 weeks after the last dose of combination study drug. The LLOQ for the assay was 25 IU/mL.

The percentage of participants with virologic response (plasma HCV RNA less than the lower limit of quantitation [< LLOQ]) after 4 weeks of combination therapy.

The percentage of participants with virologic response (plasma HCV RNA less than the lower limit of quantitation [< LLOQ]) at the end of combination therapy (12 weeks).

The percentage of participants with virologic response (plasma HCV RNA less than the lower limit of quantitation [< LLOQ]) at Weeks 4 through 12 of combination therapy.

The relationship between ABT-267 dose, ABT-267 concentration, and response was analyzed as the change in viral load (measured as log10 IU/mL) from baseline (pre-dose on Day 1) to pre-dose on Days 2 and 3. Plasma concentrations of ABT-267 pre-dose on Days 2 and 3 are presented above in 4. Primary Outcome: Plasma Concentration of ABT-267 Pre-dose (Ctrough) on Day 2 and Day 3.

Baseline (pre-dose on Day 1) samples were analyzed for resistance-associated amino acid (AA) variants using population sequencing. Phenotypic resistance to ABT-267 at Baseline was assessed by calculating the fold difference in the the half maximal effective concentration (EC50) compared with the EC50 for the appropriate reference replicon (1a-H77 or 1b-Con1). Day 3 samples were analyzed using population sequencing and were compared with the baseline and appropriate prototypic reference sequences to assess AA changes. Phenotypic resistance at Day 3 was assessed by calculating the fold difference in the EC50 compared with the EC50 for the corresponding Baseline sample. The number of participants with variants at resistance-associated AA positions and phenotypic resistance at Baseline and Day 3 are presented.