Letermovir prophylaxis to prevent viral infections after transplant in children with EBV-positive T/NK-cell disease or relapsed EBV-HLH

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

Not applicable Interventional Beijing Children's Hospital · NCT07488728

This trial tests whether giving letermovir after allogeneic stem cell transplant can prevent viral infections in children under 18 with EBV-positive T/NK-cell lymphoproliferative disease or refractory/relapsed EBV-related hemophagocytic lymphohistiocytosis who are CMV IgG positive and at high risk for CMV.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment80 (estimated)
AgesN/A to 18 Years
SexAll
SponsorBeijing Children's Hospital Academic / other
Drugs / interventionsradiation
Locations1 site (Beijing, Beijing Municipality)
Trial IDNCT07488728 on ClinicalTrials.gov

What this trial studies

This interventional study gives letermovir as prophylaxis to pediatric patients undergoing their first allogeneic hematopoietic stem cell transplant for EBV-positive T/NK-cell lymphoproliferative disease or refractory/relapsed EBV-associated HLH. Eligible children are under 18, CMV IgG positive before transplant, and have at least one predefined high-risk feature for CMV reactivation. Participants receive letermovir during the transplant period and are followed for viral infections (including CMV, EBV, BKV, HHV-6/7, RSV, ADV, HSV) as well as transplant complications such as engraftment failure, graft-versus-host disease, relapse, thrombotic microangiopathy, post-transplant lymphoproliferative disorder, immune reconstitution, and overall survival. Outcomes and safety events are recorded at the study center and analyzed to determine the effect of letermovir prophylaxis on post-transplant viral and clinical outcomes.

Who should consider this trial

Good fit: Children younger than 18 undergoing their first allogeneic HSCT for EBV-positive T/NK-cell LPD or refractory/relapsed EBV-HLH who are CMV IgG positive and have at least one high-risk factor for CMV are ideal candidates.

Not a fit: Patients with recent CMV end-organ disease, severe hepatic failure (Child-Pugh C), end-stage renal impairment, those who are CMV seronegative, or those not undergoing allo-HSCT are unlikely to receive benefit from this intervention.

Why it matters

Potential benefit: If successful, letermovir prophylaxis could reduce post-transplant viral reactivations and related complications, potentially improving survival and recovery after allo-HSCT in these high-risk children.

How similar studies have performed: Letermovir has demonstrated success preventing CMV reactivation and disease in adult HSCT recipients, but its use specifically in pediatric EBV-associated T/NK LPD and EBV-HLH populations is novel and less well studied.

Eligibility criteria

Show full inclusion / exclusion criteria
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.

Where this trial is running

Beijing, Beijing Municipality

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions EBV-associated T/NK-cell Lymphoproliferative DiseasesRefractory/Relapsed EBV-related Hemophagocytic LymphohistiocytosisLetermovirEBVEBV-associated T/NK-cell lymphoproliferative diseasesrefractory/relapsed EBV-related hemophagocytic lymphohistiocytosis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.