Elbasvir (EBR)/Grazoprevir (GZR) in Pediatric Participants With Chronic Hepatitis C Infection (MK-5172-079)

Inclusion Criteria:

- Has documented chronic HCV genotype (GT)1 or GT4 infection

- Has the following liver disease staging assessment: Absence of cirrhosis; Compensated
cirrhosis

- Has one of the following HCV treatment status: GT1 and GT4: HCV Treatment-naïve (TN)
(defined as no prior exposure to any interferon [IFN]-containing regimen, ribavirin
[RBV], or other HCV-specific direct acting antiviral (DAA) agent. GT1 only: HCV
treatment-experienced (TE). Participants cannot have previously received treatment
with HCV specific DAA agents.

- Female is not pregnant, not breastfeeding, and is either not of childbearing potential
or follows the contraceptive guidance during the treatment period and for at least 14
days after the last dose of study treatment.

- A legally acceptable representative(s) provides written informed consent for the study
and, when applicable, the participant provides written informed assent.

Exclusion Criteria:

- Has evidence of decompensated liver disease manifested by the presence of or history
of ascites, esophageal or gastric variceal bleeding, hepatic encephalopathy, or other
signs or symptoms of advanced liver disease.

- Is cirrhotic AND has a Child-Turcotte-Pugh score >6, corresponding to a Child Class B
or C.

- Is co-infected with Human Immunodeficiency Virus (HIV).

- Has evidence of past or present hepatitis B infection.

- Has a history of malignancy ≤5 years prior to signing informed consent or is under
evaluation for other active or suspected malignancy.

- Female expects to conceive or donate eggs from Day 1 through at least 14 days after
the last dose of study treatment or longer.

- Has any of the following conditions: organ transplants other than cornea and hair;
poor venous access; history of gastric surgery or malabsorption disorders; any
clinically significant cardiac abnormalities/dysfunction that may interfere with
participant treatment, assessment, or compliance; any major medical condition which
might interfere with participant treatment, assessment, or compliance; history of a
medical/surgical condition that resulted in hospitalization within the 3 months prior
to enrollment; medical/surgical conditions that may result in a need for
hospitalization during the study duration; any medical condition requiring, or likely
to require, chronic systemic administration of corticosteroids, tumor necrosis factor
antagonists, or immunosuppressant drugs; life-threatening serious adverse event (SAE)
during the screening period; history of chronic hepatitis not caused by HCV.

- Female has a positive urine pregnancy test within 24 hours before the first dose of
study treatment.

- Is taking or plans to take prohibited medications, or is taking herbal supplements.

- Has had previous HCV direct acting antiviral (DAA) treatment.

- Is currently participating or has participated in a study with an investigational
compound within prior 30 days

- Has significant emotional problems or a clinically significant psychiatric disorder
that may interfere with participant treatment, assessment, or compliance with the
protocol.

- Has clinically relevant drug or alcohol abuse within prior 12 months that may
interfere with participant treatment, assessment, or compliance.