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

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
• Is NC (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:

• Has cirrhosis of the liver
• 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 ART regimen alternative beyond their current regimen in the event of HIV virologic failure and the development of antiretroviral 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
• 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 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
• chronic pulmonary disease, including but not limited to: clinically significant chronic obstructive pulmonary disease, interstitial lung disease, pulmonary fibrosis, sarcoidosis
• 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)
• 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
• a history of stroke or transient ischemic attack
• a history of a medical/surgical condition that resulted in hospitalization within the 3 months prior to enrollment, other than for minor elective procedures
• a medical/surgical conditions that may result in a need for hospitalization during the period of the study
• any medical condition requiring, or likely to require, chronic systemic administration of corticosteroids, tumor necrosis factor (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 additiona