A Study of Letermovir (MK-8228) to Evaluate Efficacy and Safety for Prevention of CMV Infection in Chinese Hematopoietic Stem Cell Transplant Recipients (MK-8228-045)

The key inclusion and exclusion criteria include but are not limited to the following: Inclusion Criteria: Male/Female Chinese adult participant of an allogeneic Hematopoietic Stem Cell Transplant (HSCT). Has documented positive Cytomegalovirus (CMV) serostatus (CMV immunoglobulin G [IgG] seropositive) for recipient (R+) at the time of screening. Is receiving a first allogeneic HSCT. Is within 28 days post-HSCT at the time of randomization. Female participant is not a Woman of Child Bearing Potential (WOCBP) or is a WOBCP who agrees to use acceptable contraception during the treatment period and for ≥28 days after the last dose of study drug. Exclusion Criteria: Received a previous allogeneic HSCT. Has a history of CMV end-organ disease within 6 months prior to randomization. Has evidence of CMV viremia at any time from HSCT procedure until the time of randomization. Has severe hepatic insufficiency. Is a) on renal replacement therapy (e.g., hemodialysis, peritoneal dialysis) OR b) has end stage renal impairment with a creatinine clearance <=10 mL/min within 5 days prior to randomization. Has both moderate hepatic insufficiency AND moderate to severe renal insufficiency. Has an uncontrolled infection on the day of randomization. Has rapidly progressing disease that requires mechanical ventilation or is hemodynamically unstable. Has a documented positive result for a human immunodeficiency virus antibody (HIV-Ab) test at any time prior to randomization, or for hepatitis C virus antibody (HCV-Ab) with detectable HCV ribonucleic acid (RNA), or hepatitis B surface antigen (HBsAg) within 90 days prior to randomization. Has active solid tumor malignancies except localized basal cell or squamous cell skin cancer or the condition under treatment (e.g., lymphomas). Has received any prohibited medications within 2 days prior to initiation of treatment with Letermovir. Is anticipated to be treated with Traditional Chinese Medicine or herbal medicine during the study treatment period and for 14 days after study medication.