Beijing Children's Hospital, Capital Medical University
Beijing, Beijing Municipality, 100032, China
Location status: Recruiting
Recruiting
NCT Number: NCT07488728
Letermovir Prophylaxis in Children With EBV-Positive T/NK-Cell Lymphoproliferative Disease and Refractory/Relapsed EBV-Associated Hemophagocytic Lymphohistiocytosis
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.
Recruiting
Interested in participating?
Request InfoKey information
Conditions
Age range
Up to 18 year
Sex eligibility
All sexes
Study type
Interventional
Phase
Not applicable
Primary location
Who can participate
Healthy volunteers accepted: No
Only the study team can determine whether someone qualifies for participation.
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.
Treatment and study plan
Letermovir
DrugArm 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.
Primary outcomes
-
Incidence of Clinically Significant CMV Infection (cs-CMVi) and EBV Infection (cs-EBVi)
Time frame: 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.
Secondary outcomes
-
Incidence of Other Viral Infections and Transplant-Related Complications
Time frame: Up to 100, 180, 270, and 360 days post-transplant
To assess the incidence of other viral infections (e.g., BKV, HHV-6/7, RSV, ADV, HSV), graft-versus-host disease (GvHD), post-transplant lymphoproliferative disorder (PTLD), thrombotic microangiopathy (TMA), graft failure, relapse, overall survival (OS), and immune reconstitution (T/B/NK cell counts and function).
Other outcomes
-
Safety and Tolerability of Letermovir in Pediatric allo-HSCT Recipients
Time frame: From initiation of letermovir (Day 0-28 post-transplant) until 30 days after discontinuation (up to approximately 360 days post-transplant)
To monitor adverse events (AEs) and serious adverse events (SAEs) related to letermovir prophylaxis, including gastrointestinal symptoms, liver function abnormalities, cardiac events, and other treatment-emergent AEs.
Study contacts
Contact information is provided by the study sponsor or research team.
Sponsors and collaborators
Lead sponsor
Beijing Children's Hospital
Other
Registry information
Official study title
Impact of Letermovir Prophylaxis on Viral Infections After Allogeneic Hematopoietic Stem Cell Transplantation in Children With EBV-Positive T/NK-Cell Lymphoproliferative Disease and Refractory/Relapsed EBV-Associated Hemophagocytic Lymphohistiocytosis
Important dates
- Study start
- 2025
- Primary completion
- 2026
- Study completion
- 2026
- First posted
- Mar 23, 2026
- Registry last updated
- Mar 23, 2026
OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.
View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.