Single and Multiple Dose Study of Uprifosbuvir (MK-3682/IDX21437) in Healthy and Hepatitis C Virus (HCV)-Infected Participants (MK-3682-001)

Phase 1

Completed

Conditions: Chronic Hepatitis C

Interventions: Drug: Itraconazole
Drug: Uprifosbuvir
Drug: Placebo

Registration Number: NCT01974687

Lead Sponsor: Merck Sharp & Dohme LLC

Brief Summary: This is a multi-part study to evaluate the safety, tolerability, and pharmacokinetics (PK) of uprifosbuvir (MK-3682/IDX21437) in healthy participants and in participants infected with Hepatitis C virus (HCV) genotype (GT)1-GT6. The effect of food on the PK of uprifosbuvir will be evaluated. The antiviral activity of uprifosbuvir will also be assessed in HCV-infected participants.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 178

Inclusion Criteria

All Participants:

of childbearing potential must have agreed to use a double method of birth control (one of which must be a barrier) from Screening through at least 90 days after the last dose of the study drug
must not have consumed grapefruit or grapefruit juice within 7 days of Day -1 and throughout the study

HCV Participants:

documented clinical history compatible with chronic hepatitis C.
have not received direct-acting antiviral treatment for hepatitis C infection
has HCV Genotype 1, 2, 3, 4, 5 or 6

Exclusion Criteria

All Participants:

pregnant or breastfeeding
co-infected with hepatitis B virus (HBV) and/or human immunodeficiency virus (HIV).
decompensated liver disease
other clinically significant medical conditions or laboratory abnormalities.

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group A: Healthy	Placebo	Healthy participants will receive sequentially higher doses of uprifosbuvir (10 mg - 300 mg) capsules or matching placebo capsules once daily (QD) on Day 1 (Cohorts 1a-3a, 5a), Days 1 and 7 (Cohort 4a), or Day 1 - Day 7 (Cohort 6a). Dosing of next cohort will be based on review of available safety and PK data. Dosing will occur under fasted conditions with the exception of Cohort 4a, in which drug administration will occur under both fasted and fed conditions.
Group C: GT1 HCV-infected on Days 1-7	Placebo	HCV GT1 participants will receive uprifosbuvir (50 mg - 400 mg in capsules or 300 mg or 450 mg in tablets) or matching placebo capsules QD for 7 days. Dosing will commence following review of available safety and PK data of Group A. Fed vs. fasted dosing will be dependent on food effect results from Group A.
Group F: GT1 HCV-infected on Days 1-7, + Itraconazole	Itraconazole	HCV GT1 participants will receive itraconazole 200 mg twice daily (BID) on Day -5 and itraconazole 200 mg QD from Day -4 to Day 11. Participants will also be co-administered uprifosbuvir 300 mg from Day 1 to Day 7.
Group A: Healthy	Uprifosbuvir	Healthy participants will receive sequentially higher doses of uprifosbuvir (10 mg - 300 mg) capsules or matching placebo capsules once daily (QD) on Day 1 (Cohorts 1a-3a, 5a), Days 1 and 7 (Cohort 4a), or Day 1 - Day 7 (Cohort 6a). Dosing of next cohort will be based on review of available safety and PK data. Dosing will occur under fasted conditions with the exception of Cohort 4a, in which drug administration will occur under both fasted and fed conditions.
Group B: GT1 HCV-infected, treatment naive on Day 1	Uprifosbuvir	HCV GT1 participants with no prior direct-acting antiviral (DAA) exposure will receive a single dose of uprifosbuvir (10 mg - 300 mg) for 1 day across sequential dose cohorts. Dosing will commence following review of available safety and PK data from respective dose cohorts in Group A. All dosing will occur under fasted conditions.
Group C: GT1 HCV-infected on Days 1-7	Uprifosbuvir	HCV GT1 participants will receive uprifosbuvir (50 mg - 400 mg in capsules or 300 mg or 450 mg in tablets) or matching placebo capsules QD for 7 days. Dosing will commence following review of available safety and PK data of Group A. Fed vs. fasted dosing will be dependent on food effect results from Group A.
Group D: GT2 through GT6 HCV-infected on Days 1-7	Uprifosbuvir	HCV GT2 - GT6 participants will receive uprifosbuvir (50 mg - 300 mg) capsules QD for 7 days. Dosing will commence following review of available safety and PK data from Group A. Fed vs. fasted dosing will be dependent on food effect results from Group A.
Group E: GT1 HCV-infected on Days 1-7, mild hepatic impairment	Uprifosbuvir	HCV GT1 participants with mildly impaired hepatic function will receive uprifosbuvir (150 mg - 450 mg) capsules QD for 1 or 7 days. Dosing of subsequent cohorts will be based on review of available safety and PK data. Fed vs. fasted dosing will be dependent on food effect results from Group A.

Primary Outcome Measures

Name	Time	Method
Cumulative Urine Excretion of Unchanged M6 in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Cumulative urine excretion of unchanged M6 in healthy participants was obtained. All participants were fasted.
Percentage of Participants Who Experienced at Least One Treatment-emergent Adverse Event (AE)	Up to 42 days	An AE was defined as any untoward medical occurrence in a participant administered study drug, and that does not necessarily have a causal relationship with the study drug(s). An AE can be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of study drug(s), whether or not related to study drug(s). The percentage of participants who experienced at least one AE is presented.
Percentage of Participants Who Discontinued Study Drug Due to a Treatment-emergent AE	Up to 14 days	The percentage of participants who discontinued study drug due to an AE is presented.
AUC0-t of Uprifosbuvir After Single Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
Percentage of Participants Who Experienced at Least One Treatment-emergent Serious AE (SAE)	Up to 42 days	An SAE was defined as any untoward medical occurrence that at any dose that: resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. The percentage of participants who experienced at least one SAE is presented.
Percentage of Participants Who Experienced a Treatment-emergent Dose-limiting Toxicity (DLT)	Up to 13 days	A DLT was defined as any of the following events: Any SAE considered by the investigator to be at least reasonably or possibly related to study drug; Any Grade 3 clinical AE considered by the investigator to be at least reasonably or possibly related to study drug; Any Grade 3 confirmed laboratory abnormalities considered by the investigator to be at least reasonably or possibly related to study drug, except for asymptomatic Grade ¾ cholesterol and triglyceride; Any clinical or laboratory AE of any intensity that is considered by the investigator to be at least reasonably or possibly related to study drug that necessitates permanent discontinuation of study drug; Confirmed increase in QT interval corrected for heart rate using Fridericia's (QTcF) formula ≥60 msec over Baseline or an absolute QTcF ≥500 msec.
Percentage of Participants Who Experienced at Least One Treatment-emergent Grade 1, 2, 3, 4 or 5 Laboratory Abnormality	Up to 42 days	Laboratory abnormalities were graded using the Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events. Treatment-emergent AEs (TEAEs)were graded as: Grade 1: Mild TEAE as Worst Severity; Grade 2: Moderate TEAE as Worst Severity; Grade 3: Severe TEAE as Worst Severity; Grade 4: Potentially Life-Threatening TEAE as Worst Severity; Grade 5: TEAE Leading to Death. The percentage of participants who experienced at least one Grade 1, 2, 3, 4 or 5 laboratory abnormality is presented.
Area Under the Plasma Drug Concentration-Time Curve From Time Zero to Last Measurable Concentration (AUC0-t) of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration. All participants were fasted.
AUC0-t of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Healthy Participants (Group A - Cohort 6a)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
AUC0-t of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-Infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
AUC0-t of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
Cmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Time to Maximum Plasma Concentration (Tmax) of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained. All participants were fasted.
Tmax of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Tmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1, HCV-infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
t1/2 of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
AUC0-t of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Tablet Formulation in Genotype 1, HCV-Infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
AUC0-t of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
AUC0-t of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
Maximum (Peak) Observed Plasma Drug Concentration (Cmax) of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained. All participants were fasted.
Cmax of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Healthy Participants (Group A - Cohort 6a)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-Infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of Uprifosbuvir After Single Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Tablet Formulation in Genotype 1, HCV-Infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
AUC0-t of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-Infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.
Cmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-Infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained. All participants were fasted.
Tmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Healthy Participants (Group A - Cohort 6a)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Tmax of Uprifosbuvir After Singe Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Observed Terminal Half-Life (t1/2) of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained. All participants were fasted.
t1/2 of Uprifosbuvir After Single Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
Cmax of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-Infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Tmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1,HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Tmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
t1/2 of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
t1/2 of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-Infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
Reduction in HCV RNA From Baseline on Day 8 Following Uprifosbuvir 50-450 mg for 7 Days in Genotype 1, 2 and 3, HCV-Infected Participants (Groups C and D)	Baseline and Day 8	Reduction in HCV RNA from baseline on Day 8 following uprifosbuvir 50-450 mg for 7 Days in Genotype 1, 2 and 3, HCV-infected participants was obtained.
Tmax of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Tmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
t1/2 of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
t1/2 of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
AUC0-inf of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Healthy Participants (Group A - Cohort 6a)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
Tmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Tmax of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
t1/2 of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
t1/2 of Uprifosbuvir After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
t1/2 of Uprifosbuvir After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1, HCV-infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
AUC0-inf of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
AUC0-inf of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity for M6, a metabolite of uprifosbuvir, estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only. All participants were fasted.
AUC0-inf of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-Infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
AUC0-inf of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
Cmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Tmax of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained. All participants were fasted.
Tmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Healthy Participants (Group A - Cohort 6a)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Tmax of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Genotype 1, HCV-Infected Participants (Group B)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Tmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-Infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
t1/2 of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Healthy Participants (Group A - Cohort 6a)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
t1/2 of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
AUC0-inf of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-Infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
AUC0-inf of M6 After Single Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
AUC0-inf of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
Cmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-Infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Tmax of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Fed State in Healthy Participants (Group A - Cohort 4a)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
Tmax of M6 After Single Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
t1/2 of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained. All participants were fasted.
t1/2 of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants, With Itraconazole (Group F)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
AUC0-inf of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Area under the drug concentration-time curve from time zero to infinity estimated as AUC0-t + Cest/λz, where λz is the terminal elimination rate constant, calculated for the first dose only.
Maximum Reduction in log10 HCV RNA From Baseline - Normal Participants (From Groups B and C) vs. Mild Hepatic Impairment Participants (Group E)	Baseline and 28 days after last dose of study drug (Up to 42 days)	Reduction in HCV RNA from baseline on Day 8 following uprifosbuvir 50-450 mg for 7 Days in Genotype (Gt) 1, HCV-infected participants was obtained.
Cmax of M6 After Single Dose of Uprifosbuvir as the Capsule Formulation in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained. All participants were fasted.
Cmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Healthy Participants (Group A - Cohort 6a)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Cmax of M6 After Single Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Maximum observed plasma drug concentration was obtained.
Tmax of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Tablet Formulation in Genotype 1, HCV-Infected Participants (Group C)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Time to maximum plasma concentration was obtained.
t1/2 of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as the Capsule Formulation in Genotype 1, 2 and 3, HCV-Infected Participants (Groups C and D)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
t1/2 of M6 After Single Dose of Uprifosbuvir as Capsule Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 1e)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
t1/2 of M6 After Multiple Doses of Uprifosbuvir Once-Daily x 7 Days as Capsule or Tablet Formulation in Genotype 1, HCV-Infected Participants With Mildly Impaired Hepatic Function (Child Pugh Class A) (Group E - Cohort 2e and Cohort 3e)	Days 1 & 7: predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.
Cumulative Urine Excretion of Unchanged Uprifosbuvir in Healthy Participants (Group A)	Predose and 0.5, 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 36, 48, 72, 96, and 120 hours postdose	Cumulative urine excretion of unchanged MK-3682 in healthy participants was obtained. All participants were fasted.