Randomized, open-label study in treatment naïve and treatment experienced, adolescence to determine the efficacy of Sofosbuvir 400mg/ledipasvir 90mg in treatment naïve and treatment-experienced adolescence. Hepatitis C virus (HCV) infection as measured by the proportion of subjects with sustained viral response 12 weeks after discontinuation of therapy (SVR12)

Inclusion Criteria:

1. Willing and able to provide written informed consent.

2. 12-18 years

3. HCV RNA ≥ 104 IU/mL at screening.

4. Confirmed chronic HCV infection as documented by either:

   a. a positive anti-HCV antibody test or positive HCV RNA or positive HCV genotyping test at least 6 months prior to the Baseline/Day 1 visit, or

5. Screening ECG without clinically significant abnormalities.

6. Patients must have the following laboratory parameters at screening:

   • ALT (Alanine transaminase) ≤ 10 x the upper limit of normal (ULN)
   • AST (Aspartate Aminotransferase) ≤ 10 x ULN
   • Hemoglobin ≥ 12 g/dL for male, ≥ 11 g/dL for female patients
   • Platelets > 50,000 cells/mm3
   • INR (international normalized ratio) ≤ 1.5 x ULN unless subject has known hemophilia or is stable on an anticoagulant regimen affecting INR
   • Albumin ≥ 3 g/dL
   • HbA1c ≤ 10%
   • Creatinine clearance (CLcr) ≥ 60 mL/min, as calculated by the Cockcroft-Gault equation

7. Patient has not been treated with any investigational drug or device within 30 days of the screening visit.

Exclusion Criteria:

1. Chronic liver disease of a non-HCV etiology (eg, hemochromatosis, Wilson's disease, α1 antitrypsin deficiency, cholangitis).
2. Infection with hepatitis B virus (HBV) or human immunodeficiency virus (HIV).
3. History of solid organ transplantation.
4. Current or prior history of clinical hepatic decompensation (eg, ascites, variceal hemorrhage, hepatic encephalopathy, hepatorenal syndrome and hepatopulmonary syndrome).
5. History of clinically-significant illness or any other major medical disorder that may interfere with subject treatment, assessment or compliance with the protocol.
6. History of a gastrointestinal disorder (or post-operative condition) that could interfere with the absorption of the study drug.
7. History of significant pulmonary disease, significant cardiac disease or porphyria.
8. History of difficulty with blood collection and/or poor venous access for the purposes of phlebotomy.
9. Donation or loss of more than 400 mL blood within 2 months prior to Baseline/Day 1.
10. Known hypersensitivity to the study investigational medicinal product, the metabolites, or formulation excipients.