Efficacy and Safety of Grazoprevir (MK-5172) and MK-3682 With Elbasvir (MK-8742) or MK-8408 for Chronic Hepatitis C Genotype (GT) 1 and GT2 Infection (MK-3682-011)

In Part A, study therapy will be administered as separate products, each taken q.d. by
mouth. In Part B and Part C, participants will take 2 MK-3682B FDC tablets q.d. by mouth;
each MK-3682B FDC tablet contains grazoprevir 50 mg + MK-3682 225 mg + MK-8408 30 mg.

Inclusion Criteria:

Parts A and B:

- Previously untreated chronic HCV GT1 or GT2 with no evidence of non-typeable or mixed
genotype infection

- Has HCV ribonucleic acid (RNA) >= 10,000 IU/mL in peripheral blood at the time of
screening

- Has cirrhosis of the liver (Part B only) or is non-cirrhotic (Part A and B)

- Is HCV treatment naïve (defined as no prior exposure to any interferon, ribavirin, or
other approved or experimental HCV-specific direct-acting antiviral agent)

- Is of non childbearing potential or agrees to avoid becoming pregnant or impregnating
a partner beginning at least 2 weeks prior to administration of the initial dose of
study drug and either for 14 days after the last dose of study drug if not taking RBV
or for 6 months after the last dose of study drug if taking RBV (or longer if
dictated by local regulations). If not abstinent from heterosexual activity,
participants in Part A must use 2 acceptable forms of barrier contraception whereas
participants in Part B must use 2 acceptable forms of contraception which may include
oral contraceptives

Part B only:

- If coinfected with human immunodeficiency virus (HIV) is not currently on
antiretroviral therapy (ART) and has no plans to initiate ART treatment while
participating in this study OR has well controlled HIV on ART (the ART regimen must
contain only the following antiretroviral medications: tenofovir, abacavir,
lamivudine, emtricitabine, raltegravir, dolutegravir, and rilpivirine with no dose
modifications or changes in drugs in the 4 weeks prior to study entry [Day 1])

- Has at least one viable antiretroviral regimen alternative beyond their current
regimen in the event of HIV virologic failure and the development of anti-retroviral
drug resistance

Exclusion Criteria:

Parts A, B, and C (unless noted otherwise):

- Has evidence of decompensated liver disease manifested by the presence of or history
of ascites, esophageal or gastric variceal bleeding, hepatic encephalopathy or other
signs or symptoms of advanced liver disease

- For cirrhotics (Part B only), participants who are Child-Pugh Class B or C or who
have a Pugh-Turcotte (CPT) score >5, must be excluded

- Is coinfected with hepatitis B virus

- Is coinfected with HIV (Part A only)

- If coinfected with HIV (Part B only), has a history of opportunistic infection in the
preceding 6 months prior to screening

- Has a history of malignancy <=5 years prior to signing informed consent except for
adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer
or carcinoma in situ; or is under evaluation for other active or suspected malignancy

- Has cirrhosis and has had liver imaging within 6 months of Day 1 showing evidence of
hepatocellular carcinoma (HCC) or is under evaluation for HCC

- Has clinically-relevant drug or alcohol abuse within 12 months of screening

- Pregnant or breast-feeding, or expecting to conceive or donate eggs from at least 2
weeks prior to Day 1 and 90 days after the last dose of study medication, or longer
if dictated by local regulations

- Has any of the following conditions:

- organ transplants (including hematopoietic stem cell transplants) other than cornea
and hair

- poor venous access that precludes routine peripheral blood sampling required for this
trial

- has a history of gastric surgery (e.g., stapling, bypass) or history of malabsorption
disorders (e.g., celiac sprue disease)

- current or history of any clinically significant cardiac abnormalities/dysfunction,
including but not limited to: angina, congestive heart failure, myocardial
infarction, pulmonary hypertension, complex congenital heart disease, cardiomyopathy,
significant arrhythmia, uncontrolled hypertension, a history of use of antianginal or
anti-arrhythmic agents for cardiac conditions, prolonged ECG QTc interval (>470 ms
for males or >480 ms for females by the Fridericia formula) at the screening visit,
personal or family history of Torsade de pointes

- has chronic pulmonary disease, including but not limited to: clinically significant
chronic obstructive pulmonary disease, interstitial lung disease, pulmonary fibrosis,
sarcoidosis

- has central nervous system (CNS) trauma requiring intubation, intracranial pressure
monitoring, brain meningeal or skull surgery, or resulting in seizure, coma,
permanent neurologic deficits, abnormal brain imaging, or cerebral spinal fluid (CSF)
leak. Prior brain hemorrhage and/or intracranial aneurysms (whether adequately
repaired or not)

- has a current, or history of, seizure disorder unless seizure was >10 years ago, a
single isolated event, no history of or current use of anti-seizure medications
prescribed, and a normal neurological examination is documented in trial files within
6 months of Day 1

- Has a history of stroke or transient ischemic attack

- Has a history of a medical/surgical condition that resulted in hospitalization within
the 3 months prior to enrollment, other than for minor elective procedures

- Has a medical/surgical conditions that may result in a need for hospitalization
during the period of the study

- Has any medical condition requiring, or likely to require, chronic systemic
administration of corticosteroids, TNF antagonists, or other immunosuppressant drugs
during the course of the trial

- has any condition, prestudy laboratory or ECG abnormality or history of any illness,
which, in the opinion of the investigator, might confound the results of the study or
pose additional risk in administering the study drugs to the subject

- has a life-threatening SAE during the screening period

- has evidence of history of chronic hepatitis not caused by HCV, including but not
limited to nonalcoholic steatohepatitis (NASH), drug-induced hepatitis,
hemochromatosis, Wilson's disease, α1-antitrypsin deficiency, alcoholic liver
disease, and autoimmune hepatitis Parts B and C only: is a male whose female
partner(s) is/are pregnant