Efficacy and safety of primary letermovir prophylaxis for cytomegalovirus infection in paediatric patients undergoing allogeneic transplantation: a single-centre, retrospective, real-world analysis

TL;DR

This study shows that letermovir is effective and safe for preventing cytomegalovirus infection in children after stem cell transplants, especially those receiving a specific type of transplant.

Contribution

The study provides real-world evidence on letermovir's efficacy and safety in pediatric patients, a population with limited prior research.

Findings

Letermovir prophylaxis significantly reduced clinically significant CMV infection in children post-transplant.

Haploidentical donor recipients had lower CMV infection rates compared to unrelated cord blood recipients.

Letermovir was associated with similar safety outcomes and no significant adverse effects.

Abstract

Cytomegalovirus (CMV) infection is a common and life-threatening complication following allogeneic haematopoietic stem cell transplantation (allo-HSCT). Letermovir (LET) has been the standard prophylaxis for adult recipients, but studies in children remain limited.

We retrospectively analyzed children with or without LET prophylaxis after haploidentical donor (HID) for the Beijing protocol or unrelated cord blood (UCB) transplantation.

Of the 151 patients, 67 received LET, including 35 HID recipients and 32 UCB recipients. During the 180 days after transplantation, we found that the LET group had a lower incidence of clinically significant CMV infection (csCMVi) than the non-LET group (13.4% vs. 56.0%, P＜0.001). In the LET group, later LET administration was identified as a risk factor for the occurrence of csCMVi (HR: 1.07, 95% CI: 1.01 - 1.14, P=0.029). Further, the HID subgroup had a lower incidence of csCMVi during follow-up than the UCB subgroup (2.9% vs. 25.0%, P=0.009). In terms of safety, the incidence and severity of adverse events, overall survival, cumulative incidence of relapse, relapse free survival, nonrelapse mortality and graft versus host disease-free, relapse-free survival were similar between the two groups.

LET is effective and safe in preventing csCMVi among Chinese children undergoing allo-HSCT. Compared to UCB recipients, children undergoing HID transplantation for the Beijing protocol develop less scCMVi up to 180 days post-HSCT.

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