EBV mRNA Vaccine for the Prevention of EBV-Related Diseases After Allo-HSCT

Condition(s) studied

Investigational drug(s) / intervention(s)

Intramuscular injection of EBV mRNA vaccine (WGc-0401 injection): Intramuscular injection of EBV mRNA vaccine (WGc-0401 injection)

Study summary

The purpose of this clinical trial is to investigate the efficacy of the EBV mRNA vaccine (WGc-0401 injection) in preventing EBV-related diseases after allogeneic hematopoietic stem cell transplantation (allo-HSCT), and to evaluate the safety and efficacy of this vaccine in patients following allo-HSCT.

The main study questions are:

1. The incidence of grade III-IV acute graft-versus-host disease (aGVHD) within 100 days, and the occurrence of ≥ grade 3 adverse events (AEs) that are possibly or definitely related to the vaccine, in patients receiving EBV mRNA vaccination after allo-HSCT.
2. To determine the optimal biological dose (OBD) of the EBV mRNA vaccine in patients after allo-HSCT among the dose levels of 25μg, 50μg, 75μg, or 100μg.
3. EBV-ELISpot levels, the incidence of EBV viremia (EBV DNAemia), the incidence of post-transplant lymphoproliferative disorders (PTLD), disease relapse rate during follow-up, non-relapse mortality (NRM), and immunogenicity indicators (IFN-γ+ T cells, immune cell analysis, cytokine profiles, EBV glycoprotein antigen antibodies).

Participants will:

1. Receive three intramuscular injections of the EBV mRNA vaccine on days 30, 44, and 81 after allogeneic hematopoietic stem cell transplantation (d30, d44, d81).
2. Be hospitalized for at least 72 hours after each vaccination for close monitoring (with a focus on CRS and aGVHD), and undergo intensive safety assessments throughout the dose-escalation period (at least 28 days).
3. Return for clinical visits on days 7 (d37, d51, d88), day 14 (d58), and day 180 (d180) after vaccination for EBV-ELISpot, EBV-DNA quantification, and immunogenicity testing, with continued long-term follow-up to evaluate safety and the persistence of vaccine-induced immune responses.

Eligibility

Primary outcome measure(s)

• Incidence of grade III-IV acute graft-versus-host disease (aGVHD) — Up to 100 days after HSCT
  Assessed according to the modified Glucksberg criteria (or the MAGIC criteria), with clinical staging comprehensively determined by the attending physician based on the involvement of skin, upper and lower gastrointestinal tract, and liver.
• Incidence of grade ≥3 treatment related adverse events (TRAEs) — Up to 180 days after HSCT
  AEs graded per CTCAE v6.0. Grade ≥3 AEs with causality assessed as possibly, probably, or definitely related to the vaccine are captured. Systematic AE assessment at each visit covers: local injection site reactions, systemic symptoms (fever, fatigue), laboratory abnormalities (cytopenias, transaminitis), and hypersensitivity. Causality determined by investigator based on temporal association, biological plausibility, and exclusion of other causes.

Trial sites (1)

More The General Hospital of Western Theater Command trials in China