A total of 201 participants with chronic HCV GT4 infection were allocated into two groups. One group participants were treated with SOF plus RBV (24 weeks). The second group was treated with SOF plus SMV (12 weeks).

A total of 201 participants, treatment-naïve and experienced, with chronic HCV GT4 infection were allocated into two groups based on the type of the regimen used. All eligible participants were treated orally with SOF plus daily oral weight-based RBV (24 weeks; group 1), or SOF plus daily oral SMV (12 weeks; group 2).

Inclusion Criteria:

• Participants with plasma HCV RNA level >10,000 IU/L for the two groups.
• Treatment-experienced patients in group 1 were those who had previously failed treatment with classical peg-IFN/RBV therapy.
• Treatment-experienced patients in group 2 were those who had previously failed treatment with SOF/RBV

Exclusion Criteria:

• coinfected with hepatitis B virus or human immunodeficiency virus infection,
• any cause of liver disease other than HCV GT4 infection;
• liver decompensation,
• hepatocellular carcinoma,
• major severe illness, such as renal failure, congestive heart failure, thyroid dysfunction, respiratory failure, autoimmune disease and poorly controlled diabetes (HbA1C >9)
• Participants with blood picture abnormalities, such as anemia (hemoglobin concentration of 10 g/or less) and thrombocytopenia (platelet count <50,000 cells/mm3)