CMV infections after HSCT: prophylaxis and treatment.

Cytomegalovirus (CMV) infection remains a major complication in recipients of hematopoietic stem cell transplantation (HSCT) and contributes significantly to morbidity and mortality. Effective CMV prevention and management are essential for improving transplant outcomes. Preventive strategies include antiviral prophylaxis and preemptive treatments (PET). Letermovir, a terminase complex inhibitor, has become the standard of care for primary prophylaxis in CMV-seropositive recipients because of its efficacy and favorable safety profile. PET involves regular monitoring of CMV DNAemia via polymerase chain reaction (PCR) and initiation of antiviral therapy, most commonly ganciclovir or valganciclovir, upon detection of early viral reactivation. Refractory or resistant CMV infections present a significant therapeutic challenge and often require switching to a different antiviral class while awaiting genotypic resistance testing. Maribavir, a UL97 kinase inhibitor, has demonstrated superior efficacy and improved tolerability compared to conventional therapies in the phase 3 SOLSTICE trial, making it a promising therapy for refractory or resistant CMV. Optimal CMV management requires a risk-adapted, individualized approach that integrates prophylaxis, early detection, and timely intervention to reduce CMV-related complications.