To Assess the Effect of Severe Hepatic or Renal Impairment on the Pharmacokinetics of Bemnifosbuvir/Ruzasvir After a Single Dose

Inclusion Criteria:

• Must agree to use two methods of birth control from Screening through 90 days after administration of the last dose of study drug
• Females must have a negative pregnancy test at Screening and prior to dosing
• BMI of 18.5 to 43.0 kg/m2
• Willing to comply with the study requirements and to provide written informed consent

Renal Impaired Subjects (Group 1):

• Considered stable in the judgement of an Investigator
• Presence of severe renal impairment or kidney failure (as defined by eGFR< 30 mL/ min)

Hepatic Impaired Subjects (Group 2):

• Considered stable for at least 1 month prior to Screening, as per the judgement of an Investigator
• Presence of severe hepatic impairment (Child-Pugh Class C: score of 10 to 15).

Subjects with Normal Hepatic and Renal Function (Group 3):

• Medically healthy, in the opinion of an Investigator
• Must match by gender, age (± 10 years), and BMI (within 20%) to the pooled mean values of subjects with severe renal and hepatic impairment

Exclusion Criteria:

• Pregnant or breastfeeding
• Infected with hepatitis B virus, hepatitis C virus or HIV
• Abuse of alcohol or drugs
• Use of other investigational drugs within 28 days of dosing
• Other clinically significant medical conditions or laboratory abnormalities

Renal and Hepatic Impaired Subjects (Group 1 and 2):

• Presence of poorly controlled Type 1 or Type 2 diabetes as defined by Hemoglobin A1c > 10%
• Undergoing any method of dialysis
• Subjects requiring treatment for hepatic impairment or other chronic disease must be on a stable treatment plan

Renal Impaired Subjects (Group 1):

• History of renal transplant
• Concurrent use of medications known to affect the elimination of serum creatinine

Hepatic Impaired Subjects (Group 2):

• History of liver transplant
• Evidence of hepatic carcinoma presence at Screening