['chronic hepatitis c']
['grazoprevir', 'elbasvir', 'mk-5172a']

        Inclusion criteria:

          -  Has documented chronic HCV GT1 infection (for Arm 4 participants may have GT4 or GT6
             infection) with no evidence of non-typable or mixed genotype infection

          -  Has clinical evidence of hepatic cirrhosis with a score on the Child-Pugh scale from 7
             to 9 and not anticipated to receive a liver transplant within the next 36 weeks (for
             Arm 1, Arm 3, and Arm 4)

          -  Has no evidence of cirrhosis (only for Arm 2 )

          -  Agrees to remain truly abstinent or use (or have their partner use) an acceptable
             method of birth control from at least 2 weeks prior to Day 1 and continue until at
             least 14 days after last dose of study drug, or longer if dictated by local
             regulations

        Exclusion criteria:

          -  Is co-infected with hepatitis B virus or human immunodeficiency virus (HIV)

          -  Has previously received direct-acting antiviral therapy for HCV

          -  Has a history of malignancy <=5 years prior to signing informed consent except for
             adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer
             or carcinoma in situ; or under evaluation for other active or suspected malignancy

          -  Has cirrhosis and liver imaging results within 4 weeks prior to screening showing
             evidence of hepatocellular carcinoma (HCC), or is under evaluation for HCC

          -  Is currently participating or has participated in a study with an investigational
             compound within 30 days of signing informed consent and is not willing to refrain from
             participating in another such study during the course of this study

          -  Has clinically-relevant drug or alcohol abuse within 12 months of screening

          -  Is pregnant or breast-feeding, or expecting to conceive or donate eggs or sperm from
             at least 2 weeks prior to Day 1 and continue throughout treatment and follow up, or
             longer if dictated by local regulations

          -  Has received organ transplants (including hematopoietic stem cell transplants) other
             than cornea and hair

          -  Has poor venous access

          -  Has a history of gastric surgery (e.g., stapling, bypass) or history of malabsorption
             disorders (e.g., celiac sprue disease)

          -  Requires, or likely to require, chronic systemic administration of corticosteroids
             during the course of the trial

          -  Has evidence or history of chronic hepatitis not caused by HCV, including but not
             limited to nonalcoholic steatohepatitis (NASH), drug-induced hepatitis, and autoimmune
             hepatitis
      