Efficacy and safety of reduced-dose valganciclovir prophylaxis for cytomegalovirus infection after pediatric kidney transplantation.

BACKGROUND

The optimal dosing strategy for valganciclovir (VGCV) prophylaxis against cytomegalovirus (CMV) infection in pediatric patients after kidney transplantation (KT) remains uncertain because of the narrow therapeutic window between antiviral efficacy and safety.

METHODS

This study included pediatric patients who received VGCV prophylaxis after KT at a single center between December 2023 and December 2024. VGCV was administered once daily for 200 days using a reduced-dose regimen. Approximately 50% of the U.S. Food and Drug Administration-recommended dose was used for high-risk patients defined as donor-positive and recipient-negative, and 33% for intermediate-risk patients defined as recipient-positive. The incidence of CMV infection within 200 days after KT and VGCV-related adverse events (AEs) were evaluated.

RESULTS

Nine patients with a median age of 8 years were included, with a median observational period of 431 days after KT. CMV infection within 200 days occurred in four patients, all of whom were high-risk patients. No CMV disease occurred during the observational period. Neutropenia occurred in six patients, including five high-risk patients and one intermediate-risk patient. Three high-risk patients developed febrile neutropenia. VGCV dose reduction and/or discontinuation due to hematologic AEs was required in four patients.

CONCLUSIONS

The reduced-dose VGCV prophylaxis regimen was associated with a high incidence of CMV infection and AEs in high-risk patients, indicating a suboptimal balance between efficacy and safety. In intermediate-risk patients, the regimen appeared effective and tolerable. Further optimization of prophylactic strategies is required, particularly for high-risk pediatric recipients.