A Study of Different Durations of Treatment With Grazoprevir (MK-5172) in Combination With Ribavirin in Participants With Chronic Hepatitis C (MK-5172-039)

SVR12 was defined as HCV RNA \<25 IU/mL 12 weeks after the end of all study therapy. HCV RNA was measured using the Roche COBAS™ Taqman™ HCV Test, v2.0® assay, which has a lower limit of quantification of 25 IU/mL and a limit of detection of 9.3 IU/mL.

Time frame: Up to Week 36

Population: Per protocol population, as randomized. Per protocol population consists of all randomized participants receiving ≥1 dose of study therapy and no important protocol deviations.

An adverse event is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An adverse event can therefore be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an adverse event. Data are presented according to actual treatment duration (12 weeks or 24 weeks) regardless of participants' initial arm assignment.

Time frame: Up to 24 weeks

Population: The APaT population included all randomized participants who received at least 1 dose of study therapy.

An adverse event is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An adverse event can therefore be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an adverse event. Data are presented according to actual treatment duration (12 weeks or 24 weeks) regardless of participants' initial arm assignment.

Time frame: Fourteen days following last dose of study drug (up to 26 weeks)

Population: The All Participants as Treated (APaT) population included all randomized participants who received at least 1 dose of study therapy.

HCV RNA was measured using the Roche COBAS™ Taqman™ HCV Test, v2.0® assay, which has a lower limit of quantification of 25 IU/mL and a limit of detection of 9.3 IU/mL. SVR24 was defined as HCV RNA \<25 IU/mL 24 weeks after the end of all study therapy.

Time frame: Up to Week 48

Population: Per protocol population, per assigned treatment duration. Per protocol population consists of all randomized participants receiving ≥1 dose of study therapy and no important protocol deviations.

HCV RNA levels in plasma were measured using the Roche COBAS™ Taqman™ HCV Test, v2.0® assay on blood samples drawn from each participant at Week 2, Week 4, Week 12, and at end of treatment (End of Treatment Response). The assay has a lower limit of quantification of 25 IU/mL and a limit of detection of 9.3 IU/mL. Undetectable HCV RNA was defined as below the limit of detection of 9.3 IU/mL.

Time frame: From Week 2 through end of treatment (up to 24 weeks)

Population: Per protocol population, per assigned treatment duration. Per protocol population consists of all randomized participants receiving ≥1 dose of study therapy and no important protocol deviations.

HCV RNA was measured using the Roche COBAS™ Taqman™ HCV Test, v2.0® assay, which has a lower limit of quantification of 25 IU/mL and a limit of detection of 9.3 IU/mL. SVR4 was defined as HCV RNA \<25 IU/mL 4 weeks after the end of all study therapy.

Time frame: Up to Week 28

Population: Per protocol population, per assigned treatment duration. Per protocol population consists of all randomized participants receiving ≥1 dose of study therapy and no important protocol deviations.

HCV RNA levels in plasma were measured using the Roche COBAS™ Taqman™ HCV Test, v2.0® assay on blood samples drawn from each participant at Week 2, Week 4, Week 12, and at end of treatment (End of Treatment Response). The assay has a lower limit of quantification of 25 IU/mL and a limit of detection of 9.3 IU/mL. Undetectable HCV RNA was defined as below the limit of detection of 9.3 IU/mL.

Time frame: From Week 2 through end of treatment (up to 24 weeks)

Population: Per protocol population, per assigned treatment duration. Per protocol population consists of all randomized participants receiving ≥1 dose of study therapy and no important protocol deviations.

The mean time (in days) to first achievement of undetectable HCV RNA was assessed using Kaplan-Meier plot and summary statistics. HCV RNA levels in plasma were measured using the Roche COBAS™ Taqman™ HCV Test, v2.0® assay on blood samples drawn from each participant at Week 2, Week 4, Week 12, and at end of treatment. The assay has a lower limit of quantification of 25 IU/mL and a limit of detection of 9.3 IU/mL. Undetectable HCV RNA was defined as below the limit of detection of 9.3 IU/mL.

Time frame: Up to Week 24

Population: Full analysis set consists of all randomized participants receiving ≥1 dose of study therapy.