The application of rituximab during the conditioning regimen prevents Epstein - Barr virus infection following rATG-based haploidentical hematopoietic stem cell transplantation in the era of letermovir for cytomegalovirus prophylaxis

BackgroundIn the era of letermovir for cytomegalovirus (CMV) prophylaxis, several centers reported that the incidence of Epstein-Barr virus (EBV) infection were significantly increased.ObjectiveTo investigate the efficacy and safety of rituximab administration during conditioning regimen following haploidentical hematopoietic stem cell transplantation(haplo-HSCT)in the prevention of post-transplant EBV infection.MethodsWe conducted a retrospective analysis of 100 patients with acute leukemia or myelodysplastic syndrome who underwent haplo-HSCT. Patients in observation group(R group) received rituximab (375 mg/m²) on day -3 before transplantation due to the presence of donor-specific antibody (MFI ≥ 2000) (n = 25) and patients in control group (C group) did not receive rituximab (n = 75) and donor-specific antibody was low (MFI < 2000).

The primary objectives were the incidence of EBV-DNA viremia and PTLD within one-year post-transplantation. Secondary objectives included the incidence of CMV infection, cumulative incidence of acute graft-versus-host disease (aGVHD) and chronic GVHD, 100-day non-relapse mortality (NRM), progression-free survival (PFS), and overall survival (OS).ResultsNo significant differences were observed in baseline characteristics between the two groups except for primary disease.