Abstract
BACKGROUND: Cytomegalovirus (CMV) infection remains a common complication after kidney transplantation, particularly among high-risk donor-seropositive/recipient-seronegative (D+/R-) recipients. Valganciclovir is the standard first-line therapy; however, its use may be limited by hematological toxicity or impaired graft function. Maribavir is a recently approved antiviral agent with a distinct mechanism of action. CASE PRESENTATION: We report four high-risk kidney transplant recipients in whom maribavir was introduced because continued valganciclovir therapy was difficult owing to cytopenia or renal dysfunction. After switching therapy, CMV viral loads decreased in all cases, and hematological abnormalities improved following discontinuation of valganciclovir. One patient developed a drug-induced skin eruption, while no other serious adverse events were observed. No CMV recurrence or graft dysfunction occurred during follow-up. CONCLUSION: These cases highlighted practical clinical considerations for managing CMV infection when standard antiviral therapy cannot be safely continued.