Letermovir Prophylaxis in Children With EBV-Positive T/NK-Cell Lymphoproliferative Disease and Refractory/Relapsed EBV-Associated Hemophagocytic Lymphohistiocytosis
Letermovir: Arm 1 (Letermovir Prophylaxis): Pediatric patients receive oral letermovir once daily from day 0 to day 100 post-transplant. Prophylaxis may be extended to day 200 if high-risk factors persist (steroid use, poor immune reconstitution). Dosing: 480mg (≥30kg), 240mg (15-30kg), 120mg (7.5-15kg), 80mg (6-7.5kg); halved if co-administered with cyclosporine.
Arm 2 (Control): Historical control cohort (2018-2023) receiving no routine CMV prophylaxis; preemptive therapy with ganciclovir/foscarnet initiated only when plasma PCR exceeds threshold.
Study summary
This study investigates the impact of letermovir prophylaxis on viral infections (including CMV, EBV, BKV, HHV-6/7, RSV, ADV, HSV, etc.) following allogeneic hematopoietic stem cell transplantation in pediatric patients with EBV-associated T/NK-cell lymphoproliferative diseases and refractory/relapsed EBV-related hemophagocytic lymphohistiocytosis. Additionally, we examine its effects on other transplantation complications, including engraftment failure, graft-versus-host disease (GvHD), disease relapse, thrombotic microangiopathy (TMA), overall survival (OS), post-transplant lymphoproliferative disorder (PTLD) incidence, and immune reconstitution.
Eligibility
Sex
ALL
Min age
—
Max age
18 Years
Healthy volunteers
No
Inclusion Criteria:
* Diagnosed with EBV-positive T/NK lymphoproliferative disease (EBV-T/NK LPD) according to ICC 2022 criteria, or diagnosed with refractory/relapsed EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) according to the 2004-HLH diagnostic criteria;
* Undergoing first allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the study center;
* Age \< 18 years;
* CMV seropositive (IgG+) prior to transplantation;
* Presence of at least one high-risk factor for CMV infection: haploidentical transplantation, HLA-mismatched transplantation, receipt of ATG (including ATLG/ALG) in conditioning, sustained corticosteroid use post-conditioning, donor/recipient CMV serostatus mismatch, or positive NGS result pre-transplant.
Exclusion Criteria:
* History of CMV end-organ disease within 6 months prior to enrollment;
* Severe hepatic dysfunction (defined as Child-Pugh Class C);
* End-stage renal impairment with creatinine clearance \< 10 mL/min (calculated by Cockcroft-Gault equation);
* Prior allogeneic hematopoietic stem cell transplantation;
* Expected survival ≤ 3 months;
* Received radiation therapy during conditioning;
* Initiation of letermovir prophylaxis after day 28 post-transplant;
* Letermovir dosage or administration not in accordance with the prescribing information;
* Lack of signed informed consent.
Primary outcome measure(s)
Incidence of Clinically Significant CMV Infection (cs-CMVi) and EBV Infection (cs-EBVi) — Up to 180 days and 360 days post-transplant To evaluate the incidence of clinically significant CMV and EBV infections in pediatric patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT) with or without letermovir prophylaxis.
Trial sites (1)
Facility
City
Region
Status
Beijing Children's Hospital, Capital Medical University
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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