Collection of Plasma and Serum Samples From Individuals Initiating Sofosbuvir for Chronic Hepatitis C for Testing

Inclusion criteria

• The subject is chronically infected with HCV genotypes 1, 2, 3, 4, 5, and/or 6 as documented in the subject's medical records and is naïve to HCV treatment (treatment naïve).
• Chronic HCV (with or without HIV [human immunodeficiency virus] co-infection) will be documented with historical record of:
• A positive HCV RNA test result (result generated at least 6 months before the baseline visit)
• A HCV genotype test result (result generated at least 6 months before the baseline visit)
• A liver biopsy report demonstrating chronic HCV

---The subject is initiating antiviral therapy with a sofosbuvir regimen as indicated below:

• Sofosbuvir plus peginterferon and ribavirin for 12 weeks (peginterferon eligible genotype 1, 4, 5, or 6)
• Sofosbuvir plus ribavirin for 12 weeks (genotype 2)
• Sofosbuvir plus ribavirin for 24 weeks (peginterferon ineligible or unwilling genotype 1 or genotype 3)
• The subject is at least 18 years of age at the time of enrollment
• Adequate medical records are available for collection of protocol-defined demographics, baseline patient characteristics, medical history, virology and specific laboratory results, and other information to verify enrollment criteria
• The subject and/or legally authorized representative is willing and able to provide consent prior to providing a specimen(s)

Exclusion criteria

• Subjects with history or evidence of decompensated liver disease
• Subjects with severe renal impairment or end stage renal disease
• Subjects who are not naïve to HCV therapy with prior exposure to an approved or experimental HCV antiviral therapy
• Subject has characteristics that are contraindicated in the FDA approved label for sofosbuvir (eg, subjects with contraindications applicable to peginterferon and/or ribavirin, pregnant woman or men whose female partners are pregnant; Sovaldi Package Insert 2013)
• Subject is receiving treatment pre- or post-transplant
• Subject is unsuitable for study participation based on the Investigator's decision (eg, unlikely to comply with study visit schedule, significant medical complication)
• Participating in another investigational study that the Investigator believes might interfere with the subject's participation in this study