['hepatitis c virus']
['grazoprevir', 'elbasvir', 'placebo to grazoprevir', 'placebo to elbasvir']

        Inclusion Criteria:

          -  Documented chronic (at least 6 months) HCV GT 1 infection (with no evidence of mixed
             genotypes or genotype that cannot be assigned a type)

          -  Evidence or no evidence of liver cirrhosis based on one of the following:

          -  Liver biopsy performed within 24 months of Day 1 (if participant is cirrhotic then
             there is no time restriction on biopsy)

          -  Fibroscan performed within 12 months of Day 1 of this study

          -  Fibrosure™ (Fibrotest™) plus aspartate aminotransferase to platelet Ratio Index [APRI]
             obtained during the screening period)

          -  Has HCV status that is one of the following:

          -  Treatment naïve

          -  Prior interferon or pegylated interferon with or without ribavarin failures (null
             responder, partial responder, or relapser)

          -  Intolerant to prior interferon or pegylated intereferon with or without ribavarin
             regimen

          -  Chronic kidney disease (defined as glomerular filtration rate [eGFR] <=29)
             non-dialysis dependent or on hemodialysis for at least 3 months, including individuals
             awaiting kidney transplant and those with failed kidney transplants but no longer on
             immunosuppressant therapy)

          -  Female participant of reproductive potential must agree to remain abstinent or use (or
             have their partner use) 2 acceptable methods of contraception from at least 2 weeks
             prior to Day 1 through 14 days after the last dose of study drugs, or longer if
             dictated by local regulations

        Exclusion Criteria:

          -  Evidence of decompensated liver disease

          -  On peritoneal dialysis for management of kidney disease

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

          -  History of malignancy <=5 years prior to signing informed consent

          -  Clinical diagnosis of substance abuse

          -  Pregnant, breast-feeding, expecting to conceive or donate eggs, or donate sperm from
             Day 1 through 14 days after the last study dose, or longer if dictated by local
             regulations

          -  Organ transplant (including hematopoietic stem cell transplant) other than kidney,
             cornea, and hair

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

          -  Uncontrolled or poorly controlled hypertension

          -  Significant cardiovascular disorder (e.g. myocardial infarction or unstable angina) or
             cardiovascular procedure within 3 months prior to signing informed consent

          -  New or worsening signs or symptoms of congestive heart failure within 3 months of
             signing informed consent

          -  Severe active peripheral vascular disease

          -  Recent (within 3 months prior to signing informed consent) episode or recurrence of
             stroke, transient ischemic attack (TIA) or neurological disorder, including but not
             limited to seizures

          -  Evidence or history of chronic hepatitis not caused by HCV
      