A Phase 3 study evaluating Merck’s $MRK letermovir (MK-8228) for preventing clinically significant cytomegalovirus (CMV) infection in CMV-seropositive adults who have undergone an allogeneic hematopoietic stem cell transplant (HSCT) met its primary endpoint of a statistically valid percentage of patients with clinically significant CMV infection up to 24 weeks after HSCT. Final results will be presented at a future scientific conference.