An Efficacy, Safety and Pharmacokinetics Study of Simeprevir, Daclatasvir and Sofosbuvir in Participants With Chronic Hepatitis C Virus Genotype 1 or 4 Infection and Decompensated Liver Disease

This is an open-label (all people know which treatment the participants receive) Phase 2 study to investigate the efficacy, safety and pharmacokinetics of simeprevir, daclatasvir and sofosbuvir in treatment-naive (participants have never received HCV treatment with any approved or investigational agent) and treatment - experienced (participants have failed at least one previous course of \[Pegylated\] interferon \[(Peg)IFN\], with or without Ribavirin) participants. Participants will be assigned to 1 of 2 panels: Panel 1 (n=20): Child-Pugh score less than (\<) 7 with evidence of portal hypertension (confirmed by presence of esophageal varices or HVPG greater than or equal to \[\>=\] 10 mm Hg); Panel 2 (n=20): Child-Pugh score 7 to 9 (extremes included). The total study duration for each participant will be approximately 276 weeks. The study will consist of 3 parts: Screening Phase (approximately 4 weeks) and open-label treatment Phase (from Week 4 to 16) and follow-up Phase (until 5 years after the actual end of study drug treatment). Participants will receive simeprevir (150 milligram \[mg\] capsule), daclatasvir (60 mg tablet) and sofosbuvir (400 mg tablet) orally once daily for 12 weeks. Efficacy will be primarily evaluated by percentage of participants with SVR12. Participants' safety will be monitored throughout the study.