Inclusion Criteria:
* Male or female, at least 18 years of age at time of screening.
* Screening laboratory result indicating hepatitis C virus (HCV) genotype 1 (GT1) infection.
* Chronic HCV infection.
* Subject must be HCV treatment-naïve (i.e., patient has never received a single dose of any approved or investigational regimen) or treatment-experienced (has failed prior interferon \[IFN\] or pegylated IFN (pegIFN) with or without ribivarin (RBV), or sofosbuvir (SOF) plus RBV with or without pegIFN therapy).
* Subjects must be non-cirrhotic.
Additional Inclusion Criteria for HCV GT1/human immununovirus type 1 (HIV-1) co-infected patients:
* HIV-1 antiretroviral treatment (ART) naïve with CD4 ≥ 500 cells/mm3 (or CD4+ % ≥ 29%) at Screening and plasma HIV-1 RNA \<1,000 copies/mL at Screening and at least once during the 12 months prior to Screening.
OR
* On a stable, qualifying HIV-1 ART regimen for at least 8 weeks prior to screening, with CD4 ≥ 200 cells/mm3 (or CD4+ % ≥14%) at Screening and plasma HIV-1 RNA \< LLOQ at Screening and at least once during the 12 months prior to Screening.
Exclusion Criteria:
* History of severe, life-threatening or other significant sensitivity to any excipients of the study drugs.
* Female who is pregnant, planning to become pregnant during the study or breastfeeding; or male whose partner is pregnant or planning to become pregnant during the study.
* Recent (within 6 months prior to study drug administration) history of drug or alcohol abuse that could preclude adherence to the protocol in the opinion of the investigator.
* Positive test result at Screening for hepatitis B surface antigen (HBsAg).
* HCV genotype performed during screening indicating co-infection with more than one HCV genotype.
* Chronic HIV type 2 (HIV-2) infection.
