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.

Safety Population: all participants who received at least one dose of the study drug

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.

Safety Population: all participants who received at least one dose of the study drug

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.

Safety Population: all participants who received at least one dose of the study drug

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.

Safety Population: all participants who received at least one dose of the study drug

The percentage of participants who discontinued study drug due to an AE is presented.

Safety Population: all participants who received at least one dose of the study drug

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration. All participants were fasted.

Pharmacokinetics (PK) Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

AUC0-t was calculated using linear log trapezoidal summation from time zero to last measurable concentration.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Maximum observed plasma drug concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Time to maximum plasma concentration was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

The time measured for the plasma concentration to decrease by one half (t1/2) was obtained.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Cumulative urine excretion of unchanged MK-3682 in healthy participants was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

Cumulative urine excretion of unchanged M6 in healthy participants was obtained. All participants were fasted.

PK Population: a subpopulation of the per-protocol population, selecting all participants exposed to uprifosbuvir who had available and evaluable data (e.g., excluding deviations and/or other events that could have an impact on the PK analysis).

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.

Per-Protocol Population: participants who complied with the protocol sufficiently to ensure that these data were likely to exhibit the effects of treatment, according to the underlying scientific model.

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.

Per-Protocol Population: participants who complied with the protocol sufficiently to ensure that these data were likely to exhibit the effects of treatment, according to the underlying scientific model.