['hepatitis c virus']
['grazoprevir (gzr)', 'elbasvir (ebr)', 'ribavirin (rbv)']

        Inclusion criteria:

          -  Documented chronic HCV GT1 infection (with no evidence of non-typable or mixed
             genotype)

          -  Absence of cirrhosis, or cirrhosis with these criteria: METAVIR F4, or Fibroscan with
             result >12.5 kPa, or FibroSure® (Fibrotest®) score of >0.75 + aspartate
             aminotransferase (AST): platelet ratio index (APRI) of >2- Prior regimen containing an
             approved DAA (boceprevir, telaprevir, simeprevir, or sofosbuvir), pegylated
             interferon, and/or RBV

          -  Participants of reproductive potential must agree to remain truly abstinent or use (or
             have their partner use) 2 acceptable methods of birth control from at least 2 weeks
             prior to Day 1 and continue until at least 6 months after last dose of study drug, or
             longer if dictated by local regulations

        Exclusion criteria:

          -  Received any HCV regimen containing a DAA with the exception of boceprevir,
             telaprevir, simeprevir, or sofosbuvir in combination with pegylated interferon and/or
             RBV

          -  Evidence of decompensated liver disease or cirrhosis

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

          -  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

          -  Evidence of hepatocellular carcinoma (HCC) or under evaluation for HCC

          -  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

          -  Clinically-relevant drug or alcohol abuse within 12 months of screening

          -  Pregnant, 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

          -  Male participant whose female partner (s) is/are pregnant

          -  Organ transplants (including hematopoietic stem cell transplants) other than cornea
             and hair

          -  Poor venous access

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

          -  Hemoglobinopathy, including, but not limited to, thalassemia major

          -  Any medical condition requiring, or likely to require, chronic systemic administration
             of corticosteroids during the course of the trial

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