A Study to Investigate the Pharmacokinetic Interactions Between Simeprevir and Ledipasvir in a Treatment Regimen Consisting of Simeprevir, Sofosbuvir, and Ledipasvir in Treatment-naive Participants With Chronic Hepatitis C Virus Genotype 1 Infection

This is an open-label (all people know the identity of the intervention), 2-panel, Phase 2, randomized (study medication assigned to participants by chance) study. The study will consist of 3 study phases: Screening Phase (5 weeks), an Open-label Treatment Phase (70 days for Panel 1 and 56 days for Panel 2), a Post-treatment Follow-up Phase (12 weeks after the actual end of treatment). Participants will receive a combination of the following treatments: Treatment A: SMV 150 milligram (mg) once daily; Treatment B: LDV 90 mg along with SOF 400 mg once daily; Treatment C: SOF 400 mg once daily. Participants will be randomly assigned to Panel 1 (Treatment AC followed by Treatment AB) and Panel 2 (Treatment B followed by Treatment AB). The total study duration will be approximately 27 weeks for participants in Panel 1 and 25 weeks for participants in Panel 2. Participants will be primarily accessed for pharmacokinetic parameters. Participants' safety will be monitored throughout the study.

Inclusion criteria

• Participants with Body Mass Index (weight in kilogram [kg] divided by the square of height in meters) of 18.0 to 35.0 kilogram per square meter kg/m^2, extremes included
• Participants must be treatment-naive (that is, have not received prior treatment with any approved or investigational drug)
• Participants with HCV ribonucleic acid (RNA) plasma levels greater than (>) 10,000 international unit per milliliter (IU/ml) and lower than 6,000,000 international unit per milliliter (IU/ml) at screening
• Participants with absence of cirrhosis confirmed by FibroTest/Fibrosure score less or equal to 0.75 and an aspartate aminotransferase to platelet ration index less or equal to 2 or a Fibroscan less or equal to 14.6 kilopascale (kPA), performed within 6 months prior or during the screening period
• Participants with documented chronic HCV infection: diagnosis of HCV infection >6 months prior to screening, either by detectable HCV RNA, an HCV positive antibody test or presence of histological changes consistent with chronic hepatitis in a liver biopsy

Exclusion criteria

• Participant has infection/co-infection with HCV of a genotype other than genotype 1, human immunodeficiency virus (HIV) type 1 or 2
• Participant has any evidence of liver disease of non-HCV etiology. This includes, but is not limited to acute hepatitis A, active hepatitis B, drug- or alcohol-related liver disease, autoimmune hepatitis, hemochromatosis, Wilson's disease, alpha-1 antitrypsin deficiency, non-alcoholic steatohepatitis, primary biliary cirrhosis, or any other non-HC liver disease considered clinically significant by the investigator
• Participant with significant co-morbidities, conditions or clinical significant findings during screening assessments that in the opinion of the investigator could compromise the participants' safety or could interfere with the Participant participating in and completing the study
• Participant received an organ transplant (other than cornea or hair transplant or skin graft)
• Participants have key protocol defined laboratory abnormalities