An Efficacy and Safety Study of a 8 or 12-Week Treatment Regimen of Simeprevir in Combination With Sofosbuvir in Treatment-Naive and Experienced Participants With Chronic Genotype 4 Hepatitis C Virus Infection

Inclusion Criteria:

• Participant must have hepatitis C virus (HCV) genotype 4 infection (confirmed at screening)
• Participant must have HCV ribonucleic acid (RNA) greater than (>) 10,000 international unit per milliliter (IU/mL) at screening
• In participants with cirrhosis, a documented hepatic imaging procedure (ultrasound, computed tomography [CT] scan, or magnetic resonance imaging [MRI]) within 6 months before baseline (Day 1) to exclude hepatocellular carcinoma is required
• A woman of childbearing potential must have a negative serum (beta human chorionic gonadotropin at screening and a negative urine pregnancy test on Day 1 before first dose of study drug
• Females of childbearing potential or males with a female partner of childbearing potential must agree to use 2 highly effective contraceptive methods (one of which is a barrier method; eg, condom or diaphragm) from Day 1 (baseline) and continue until 30 days after the end of treatment (EOT) (or longer if dictated by local regulations), or not be heterosexually active, or be a vasectomized male subject or a female subject with a vasectomized partner, or be a female (subject or partner of male subject) of non-childbearing potential (ie, postmenopausal for at least 2 years or surgically sterile)

Exclusion Criteria:

• Participant has evidence of clinical hepatic decompensation (history or current evidence of ascites, bleeding varices, or hepatic encephalopathy)
• Participant has any liver disease of non-HCV etiology. This includes, but is not limited to, acute hepatitis A, 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-HCV liver disease considered clinically significant by the investigator
• Participant is infected/co-infected with non-genotype 4 HCV
• Participant has any other active clinically significant disease or clinically significant findings during screening of medical history, physical examination, laboratory testing or electrocardiogram (ECG) recordings that, in the investigator's opinion, would compromise the participant's safety or could interfere with the participant participating in and completing the study
• Participant has history of malignancy within 5 years of the screening visit (exceptions: skin carcinomas, carcinoma in situ of the cervix, or malignancy that in the opinion of the investigator is considered cured with minimal risk of recurrence)