A Study to Evaluate the Safety and Efficacy of Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir With Ribavirin in Adults With Genotype 1 and Ombitasvir/Paritaprevir/Ritonavir With Ribavirin in Adults With Genotype 4 Chronic Hepatitis C Virus Infection and Decompensated Cirrhosis

1. HCV GT1- or GT4-infection defined as: positive for anti-HCV Ab, HCV RNA \> 1,000 IU/mL and laboratory result indicating HCV GT1 or GT4 infection at Screening. 2. Evidence of cirrhosis by prior liver biopsy, FibroScan or by radiograph (i.e., computed tomography \[CT\] scan or magnetic resonance imaging \[MRI\]). 3. Child-Pugh Score of 7 - 9, inclusive, at time of Screening.

1. Women who are pregnant or breastfeeding. 2. Positive test result for Hepatitis B surface antigen (HbsAg) or anti-HIV antibodies (HIV Ab). 3. Prior or current use of any other investigational or commercially available anti-HCV agents other than interferon/RBV and/or pegylated interferon (pegIFN)/RBV (including but not limited to telaprevir, boceprevir, sofosbuvir and simeprevir). 4. Confirmed presence of hepatocellular carcinoma indicated on imaging techniques such as CT scan or MRI within 3 months prior to Screening or on an ultrasound performed at Screening (a positive ultrasound result will be confirmed with CT scan or MRI). 5. Any current or past evidence of Child-Pugh C classification.