The main purpose of the study is to determine the antiviral efficacy and evaluate the safety and tolerability of sofosbuvir/ velpatasvir (SOF/VEL) and sofosbuvir/ velpatasvir/ voxilaprevir (SOF/VEL/VOX) used to treat individuals with chronic hepatitis C virus infection in Rwanda adults.

This is an open-label single-arm study that will examine the antiviral efficacy, safety and tolerability of 12 weeks daily therapy with fixed dose combination (FDC) of SOF/VEL and SOF/VEL/VOX administered respectively in HCV-infected treatment-naïve adult participants and in HCV-infected individuals with a history of virologic failure to SOF/LDV or other DAA-containing regimen. A total of 100 participants will be enrolled in this portion of the SHARED study, labelled the "SHARED 3 study": 60 treatment-naïve participants and 40 individuals with history of virologic failure to SOF/LDV or other DAA-containing regimen

Inclusion Criteria:

• Willing and able to provide written informed consent

• Age ≥ 18 years

• HCV RNA >1000 IU/mL at Screening

• For SOF/VEL arm, HCV treatment-naïve or interferon/ribavirin-experienced

• For SOF/VEL/VOX arm, history of virologic failure to SOF/LDV or other DAA-containing regimen as defined by a quantifiable HCV viral load any time at or after the end of HCV therapy

• Screening ultrasound excluding hepatocellular carcinoma (HCC)

• Acceptable laboratory values including:

  • Hemoglobin ≥8.0 g/dL
  • Platelet count ≥40,000/mm3
  • AST, ALT, and alkaline phosphatase ≤10 × ULN
  • Calculated creatinine clearance (CrCl) ≥30 mL/min

• General good health

• Ability to comply with the dosing instructions for study drug administration and to complete the study schedule of assessments

• If HIV-infected:

  • The participant must have completed at least 6 months of any approved HIV antiretroviral therapy (ART) before starting enrollment
  • The participant at time of screening and for at least 2 weeks prior to screening must be on ART compatible with SOF/VEL and SOF/VEL/VOX
  • Screening HIV RNA < 200 copies/mL
  • Screening CD4 T-cell count of ≥100 cells/µL

• Women of reproductive potential must have a negative urine pregnancy test at Screening and a negative urine pregnancy test at Entry prior to enrollment.

Exclusion Criteria:

• Current or history of clinical hepatic decompensation (i.e., ascites, encephalopathy or variceal hemorrhage)
• Active tuberculosis
• Other clinically-significant illness (except HCV and/or HIV) or any other major medical disorder that, in the opinion of the site investigator, may interfere with participant treatment, assessment or compliance with the protocol; participants currently under evaluation for a potentially clinically-significant illness (other than HCV/HIV) are also excluded.
• Active Hepatitis B infection
• Difficulty with blood collection and/or poor venous access for the purposes of phlebotomy
• Pregnant or nursing female
• Active drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study procedures and treatment