Cytomegalovirus (CMV) reactivation is a major concern following haploidentical hematopoietic stem cell transplantation (HSCT). Letermovir is a novel CMV deoxyribonucleic acid terminase complex inhibitor without hematological and nephrotoxicity compared to traditional treatments. This case report compares two adult male patients with relapsed/refractory acute myeloid leukemia who underwent haploidentical HSCT with similar conditioning and immunosuppressive treatments. Patient 1 (36 years old) received letermovir starting on the day of transplant and remained CMV-negative during recovery. Although he experienced some issues like BK virus and acute kidney injury, he reached full donor chimerism and had no CMV-related problems. Patient 2 (52 years old) did not receive letermovir. He developed CMV reactivation confirmed by polymerase chain reaction and required treatment with ganciclovir. He also developed thrombocytopenia and graft-versus-host disease. This dual case comparison demonstrates the efficacy of letermovir prophylaxis in preventing CMV reactivation following haploidentical stem cell transplant. It supports the inclusion of letermovir in standard transplant protocols to improve the outcomes in resource-limited settings using affordable, bioequivalent formulations.
Lavana et al. (2026) studied this question.