Safety, Tolerability, and Antiviral Activity of ACH-0141625 or Placebo in Combination With Peginterferon and Ribavirin in Hepatitis C Virus (HCV) Positive Participants

Inclusion criteria

• Males and females, aged 18 years and older
• Chronic hepatitis C genotype 1 (as specified in the protocol)
• Treatment naive
• Females who are post-menopausal and amenorrheic must have a follicle-stimulating hormone (FSH) at screening. Females of childbearing potential must have a negative pregnancy test at screening and baseline. Females must use a non-hormonal method of contraception and must agree not to get pregnant during the study and for 6 months following the discontinuation of standard of care (SOC).
• Fertile males must agree to use a condom and his female partner must agree to use 1 or more methods of contraception. Males must not donate sperm during the study and 3 months following the last exposure to RBV.

Exclusion criteria

• Body mass index (BMI) >36 kilograms (kg)/square meter (m^2)
• Pregnant or nursing females or females of childbearing potential not willing to comply with contraceptive measures per protocol. Men whose female partners are pregnant or contemplating pregnancy. - Coinfection with hepatitis B virus (HBV) and/or human immunodeficiency virus (HIV)
• Other significant diseases including liver disease
• History of drug or alcohol dependence or addiction within the past 6 months
• History of participation in a clinical trial with a protease inhibitor or previous treatment with a protease inhibitor, where at least 1 dose of the protease inhibitor was consumed.
• Use of herbal or homeopathic products, illicit drugs, cytochrome P450 (CYP) 3A4/5 substrates, inducers or inhibitors, hormonal methods of contraception, corticosteroids, immunosuppressive, or cytotoxic agents within 28 days of the first dose of study drug.
• Have a clinically significant laboratory abnormality at screening (as specified in the protocol).
• Segment 1: Participants with any history of decompensated liver disease defined as cirrhotic participants with a Child-Pugh score of > or = to 7. Segment 2: Participants who have had a liver biopsy that shows bridging fibrosis or cirrhosis.
• Nonalcoholic steatohepatitis if ballooning degeneration or Mallory bodies are present on liver biopsy.
• Participants who prematurely discontinued, interrupted, or dose reduced prior Peg-IFN and RBV therapy due to noncompliance or safety issues.
• Encephalopathy or altered mental status of any etiology.
• History of moderate, severe, or uncontrolled psychiatric disease (as specified in the protocol).
• History of malignancy of any organ system treated or untreated within the past 5 years.
• Use of colony stimulating factor agents within 90 days prior to baseline.
• History of seizure disorder.
• History of known coagulopathy including hemophilia.
• Clinically of significant findings on fundoscopic or retinal examination at screening
• History of immunologically mediate disease.
• History of clinical evidence of chronic cardiac disease (as specified in the protocol)
• Received concomitant systemic antibiotic, antifungals, or antivirals for the treatment of active infection within 14 days prior to the first dose of the study drug (as specified in the protocol)