A Study to Investigate the Safety, Pharmacokinetics, and Efficacy of Combination Treatment of AL-335, Odalasvir, and Simeprevir in Japanese Participants With Chronic Hepatitis C Genotype 1 or 2 Virus Infection, With or Without Compensated Cirrhosis Who Are Direct Acting Antiviral Treatment-naive

A Phase 2a, Multicenter, Open-label Study to Investigate the Safety, Pharmacokinetics, and Efficacy of Combination Treatment of AL-335, Odalasvir, and Simeprevir in Japanese Subjects With Chronic Hepatitis C Genotype 1 or 2 Virus Infection, With or Without Compensated Cirrhosis Who Are Direct Acting Antiviral Treatment-naïve

The main purpose of this study is to evaluate the safety and tolerability of a combination treatment of AL-335, odalasvir (ODV), and simeprevir (SMV) for 8 weeks in Japanese participants with genotype 1 or 2 chronic hepatitis C virus (HCV) infection without cirrhosis and for 12 weeks in direct-acting antiviral (DAA)-naive Japanese participants with genotype 1 or 2 chronic HCV infection with compensated cirrhosis.

Inclusion Criteria:

• Chronic hepatitis C virus (HCV) infection
• All participants must have HCV genotype 1 or 2 infection, determined at screening
• HCV ribonucleic acid (RNA) plasma levels greater than or equal to (>=)10,000 international units per Milliliter (IU/mL), determined at screening
• Direct-acting antiviral (DAA)-naive participants, defined as not having received treatment with any approved or investigational DAA drug for chronic HCV infection; prior HCV therapy consisting of interferon (IFN, pegylated or nonpegylated) with or without ribavirin (RBV) is allowed
• Participants without cirrhosis or with compensated cirrhosis

Exclusion Criteria:

• Infection with HCV genotype - 3, 4, 5, or 6
• Co-infection with human immunodeficiency virus (HIV 1 or HIV 2 antibody positive) or hepatitis B virus (HBV) (hepatitis B surface antigen [HBsAg] positive)
• Prior treatment with any investigational or approved HCV DAA, either in combination with PegIFN or IFN free
• Any evidence of liver disease of non-HCV etiology. This includes, but is not limited to, acute hepatitis A infection (immunoglobulin M), drug or alcohol related liver disease, autoimmune hepatitis, hemochromatosis, Wilson's disease, alpha 1 antitrypsin deficiency, primary biliary cirrhosis, or any other non-HCV liver disease that is considered clinically significant by the investigator
• Evidence of hepatic decompensation as assessed with Child-Pugh Class B or C or any of the following: history or current clinical evidence of ascites, bleeding varices, or hepatic encephalopathy