Durability of Virologic Response and/or Viral Resistance Patterns in Participants With Chronic Hepatitis C Who Have Been Previously Treated With Grazoprevir (MK-5172) (MK-5172-017)

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The study investigator determined whether the adverse event was drug-related.

Time frame: Up to ~ 60 months after enrollment in this study

Population: All participants treated with GZR in a prior study. Three participants were excluded from analysis; two participants enrolled in error failed to receive at least one dose of GZR in a prior study (each received a comparator regimen in a prior base study) and one participant had insufficient long-term follow-up data (participant withdrew consent on Day 27).

A serious adverse event (SAE) is any adverse experience occurring at any dose that either results in death, is life threatening, results in a persistent or significant disability/incapacity, results in or prolongs an existing inpatient hospitalization, is a congenital anomaly/birth defect, is a cancer, is an overdose (whether accidental or intentional), or other important medical events that may not result in death, not be life threatening, or not require hospitalization may be considered a serious adverse experience when, based upon appropriate medical judgment, the event may jeopardize the participant and may require medical or surgical intervention to prevent one of the outcomes listed previously. The study investigator determined whether the adverse event was drug-related.

Time frame: Up to ~60 months after enrollment in this study

Population: All participants treated with GZR in a prior study. Three participants were excluded from analysis; two participants enrolled in error failed to receive at least one dose of GZR in a prior study (each received a comparator regimen in a prior base study) and one participant had insufficient long-term follow-up data (participant withdrew consent on Day 27).

An ECI includes spontaneous bacterial peritonitis, variceal bleeding, ascites, encephalopathy, hepatorenal syndrome, hepatocellular carcinoma, liver transplant, cardiovascular disease limited to angina and myocardial infarction, neurologic disorders limited to transient ischemic attack (TIA) or stroke, graft rejection in participants who have undergone liver or kidney transplant, or one of the following in participants from the MK-5172-052 (NCT02092350) base study: kidney transplant, decreased estimated glomerular filtration rate (eGFR), new onset diabetes, cryoglobulinemia, or post transplantation glomerulonephritis.

Time frame: Up to ~60 months after enrollment in this study

Population: All participants treated with GZR in a prior study. Three participants were excluded from analysis; two participants enrolled in error failed to receive at least one dose of GZR in a prior study (each received a comparator regimen in a prior base study) and one participant had insufficient long-term follow-up data (participant withdrew consent on Day 27).

In adult participants with HCV RNA ≥1000 IU/mL at entry or during the study period, HCV sequence analysis was performed to evaluate the presence of RASs and the persistence of RASs over time.

Time frame: Up to ~60 months after enrollment in this study

Population: Participants met the criteria of virologic failure either in the prior base study or had HCV RNA Target detected, quantifiable \[TD(q)\] at entry in current study. Participants did not receive new HCV therapy between the end of the prior base study and entry into this study. Only HCV genotype infections that had adequate reference information were included.

In adult participants with HCV RNA ≥1000 IU/mL at entry or during the study period, HCV sequence analysis was performed to evaluate the presence of RASs and the persistence of RASs over time.

Time frame: Up to ~60 months after enrollment in this study

Population: Participants met the criteria of virologic failure either in the prior base study or had HCV RNA TD(q) at entry in current study. Participants did not receive new HCV therapy between the end of the prior base study and entry into this study. Only HCV genotype infections that had adequate reference information were included.

In adult participants with HCV RNA ≥1000 IU/mL at entry or during the study period, HCV sequence analysis was performed to evaluate the presence of RASs and the persistence of RASs over time.

Time frame: Up to ~60 months after enrollment in this study

Population: Participants met the criteria of virologic failure either in the prior base study or had HCV RNA TD(q) at entry in current study. Participants did not receive new HCV therapy between the end of the prior base study and entry into this study. Only HCV genotype infections that had adequate reference information were included.

Viral relapse is defined as any participant who has confirmed HCV Ribonucleic acid (RNA) ≥ Lower limit of quantification (LLoQ) of 15 IU/mL and had achieved sustained virologic response (SVR) in the follow up in the prior treatment study. Time to relapse is defined as the time from last dose of study therapy taken in the prior treatment study until the date where HCV RNA is ≥LLoQ.

Time frame: Up to ~60 months after enrollment in this study

Population: All participants who achieved SVR during the follow-up period of the prior treatment study and did not start any new HCV therapy between the end of the prior treatment study and entry in this study