Part A: Drug Interaction Study of Sofosbuvir and Antiretroviral Therapy (ART) Combinations in HIV and Hepatitis C Virus (HCV) Co-infected Patients. Part B: Efficacy and Safety of Sofosbuvir for 12 Weeks in HIV/HCV Co-infected Patients.
Part A: Drug Interaction Study of Sofosbuvir and Antiretroviral Therapy (ART) Combinations in HIV and Hepatitis C Virus (HCV) Co-infected Patients. Part B: Efficacy and Safety of Sofosbuvir for 12 Weeks in HIV/HCV Co-infected Patients.
This study consists of 2 parts, Part A and Part B. Part A, the Phase 1 drug interaction/early
 viral kinetic study, will evaluate the effect of selected antiretroviral therapies on the
 safety, viral kinetics, and pharmacokinetics of sofosbuvir (GS-7977; PSI-7977) and its
 metabolites in participants with HIV and hepatitis C virus (HCV) coinfection. Part B, the
 Phase 2 treatment study, will investigate the efficacy and safety of sofosbuvir, pegylated
 interferon alpha (PEG) and ribavirin (RBV) in participants with HIV/HCV coinfection.
Inclusion Criteria:

 -  Healthy according to medical history and physical examination with exception of HCV
 and HIV diagnoses

 -  Confirmation of Chronic HCV infection

 -  Confirmation of Chronic HIV-1 infection

 -  On a stable protocol approved HIV antiretroviral (ARV) regimen with undetectable
 HIV-RNA

 -  Agree to use two forms of highly effective contraception for the duration of the study
 and 6 months after the last dose of study medication

 -  Subjects must be naive to treatment for chronic HCV infection

 Exclusion Criteria:

 -  Known or suspected cirrhosis

 -  History of any other clinically significant chronic liver disease

 -  A history consistent with decompensated liver disease.

 -  Use of any prohibited medications as defined by the protocol

 -  Pregnant or nursing female or male with pregnant female partner

 -  Contraindication to PEG or RBV therapy (for Part B)

 -  Clinically relevant drug or alcohol abuse