['chronic hepatitis c']
['ravidasvir', 'danoprevir', 'ritonavir', 'ribavirin']

        Inclusion Criteria:

          -  Willing and able to provide written informed consent

          -  Chronic HCV infection (≥6 months) , HCV RNA ≥ 1 × 104 IU/mL

          -  Never received prior-treatment for HCV with interferon, RBV, or other direct-acting or
             host-targeting antivirals for HCV

          -  Chronic liver disease consistent with CHC infection without cirrhosis as determined by
             biopsy obtained within the past calendar 36 months using one of the liver biopsy
             methods in the protocol (non-cirrhosis is defined as: Metavir score ˂ 4), or as
             determined by Fibroscan defined as: ˂ 14.6 kPa. Patients who have not obtained a liver
             biopsy or Fibroscan in the last 3 years will have a study related Fibroscan performed
             in order to confirm the diagnosis. Liver biopsy will be performed by investigator's
             judgement

          -  All male patients with female partners of childbearing potential must use two reliable
             forms of effective contraception (combined) during treatment and for 6 months
             following the last dose of ribavirin

          -  Others as specified in detailed protocol.

        Exclusion Criteria:

          -  Pregnant or lactating women.

          -  History or presence of decompensated liver disease (history of ascites, hepatic
             encephalopathy, HCC, or bleeding esophageal varices)

          -  Presence or history of non-hepatitis C chronic liver disease, including but not
             limited to, autoimmune hepatitis, α-1-antitrypsin deficiency, C282Y homozygous
             hemochromatosis, Wilson's disease, drug- or toxin-induced liver disease,
             alcohol-related liver disease, primary biliary cirrhosis, sclerosing cholangitis, and
             porphyria cutanea tarda causing liver pathology or requiring phlebotomy

          -  Positive hepatitis B surface antigen or HIV antibody at screening

          -  History or presence of liver cirrhosis

          -  History of severe psychiatric disease, including psychosis and/or depression, who is
             not able to participate or able to give written informed consent and to comply with
             the study restrictions

          -  History of active malignancy within the last 5 years, with the exception of localized
             or in situ carcinoma (e.g., basal or squamous cell carcinoma of the skin)

          -  History of severe cardiac disease (e.g., New York Heart Association Functional Class
             III or IV, myocardial infarction within 6 months, ventricular tachyarrhythmia's
             requiring ongoing treatment, unstable angina or other unstable, uncontrolled or
             significant cardiovascular disease within 6 months). Patients with stable coronary
             artery disease (e.g., 6 months after by-pass surgery, angioplasty with or without
             stent placement, etc.) as confirmed by a cardiologist will be permitted. In addition,
             patients with documented or presumed unstable coronary artery disease, cardiovascular
             disease, or cerebrovascular disease should not be enrolled.

          -  Any patient with an increased risk for anemia (e.g., thalassemia, sickle cell anemia,
             or spherocytosis) or for whom anemia would be medically problematic

          -  History of pre-existing renal disease, patients with a history of nephrolithiasis will
             be allowed

          -  Others as specified in detailed protocol.
      