Letermovir (MK-8228) Versus Placebo in the Prevention of Clinically-Significant Cytomegalovirus (CMV) Infection in Adult, CMV-Seropositive Allogeneic Hematopoietic Stem Cell Transplant Recipients (MK-8228-001)

Inclusion Criteria: * Has documented seropositivity for CMV within 1 year before hematopoietic stem cell transplant (HSCT) * Receiving first allogeneic HSCT (bone marrow, peripheral blood stem cell, or cord blood transplant) * Female or male participant who is not of reproductive potential, or, if of reproductive potential, agrees to true abstinence or to use (or have their partner use) 2 acceptable methods of birth control from the time of consent through 90 days after the last dose of study drug * Able to read, understand, and complete questionnaires and diaries Exclusion Criteria: * Received a previous allogeneic HSCT (previous autologous HSCT is acceptable) * History of CMV end-organ disease within 6 months before randomization * Has evidence of CMV viremia (if tested) at any time from either signing of the Informed Consent Form or the HSCT procedure, whichever is earlier, until the time of randomization. * Received the following within 7 days before screening or plans to receive during the study: ganciclovir, valganciclovir, foscarnet, acyclovir, valacyclovir, or famciclovir * Received the following within 30 days before screening or plan to receive during the study: cidofovir, CMV hyper-immune globulin, any investigational CMV antiviral agent or biological therapy * Has suspected or known hypersensitivity to ingredients of MK-8228 (letermovir) formulations * Has severe hepatic insufficiency within 5 days before randomization * Has end-stage renal impairment * Has an …