Low-dose antithymocyte globulin plus low-dose posttransplant cyclophosphamide combined with cyclosporine and mycophenolate mofetil for prevention of graft-versus-host disease after HLA-matched unrelated donor peripheral blood stem cell transplantation.

The standard regimens for graft-versus-host disease (GvHD) prophylaxis in matched unrelated donor (MUD) transplantation were based on antithymocyte globulin (ATG) in combination with calcineurin inhibitors (CNIs). To improve the efficiency of GvHD prophylaxis in MUD peripheral blood stem cell transplantation (MUD-PBSCT), 51 patients with hematological malignancies received a novel regimen for GvHD prophylaxis, which is composed of low dose of ATG (5 mg/kg) plus low-dose posttransplant cyclophosphamide (PTCy, 50 mg/kg) (low-dose ATG/PTCy) combined with cyclosporine A (CsA) and mycophenolate mofetil (MMF). The cumulative incidences (CIs) of grades I-IV and II-IV acute GvHD (aGvHD) were 14.5% (95% CI, 9.4-19.6%) and 6.2% (95% CI, 2.8-9.6%) within 100 days after transplantation, respectively. The CI of mild-to-moderate chronic GvHD (cGvHD) within 1 year was 11.5% (95% CI, 6.6-16.4%). The 1-year probabilities of GvHD and relapse-free survival, relapse-free survival, and over survival were 70.6% (95% CI, 64.2-77.0%), 76.5% (95% CI, 70.6-82.4%), and 82.0% (95% CI, 76.5-87.5%), respectively. The CIs of CMV and EBV reactivation by day 180 were 10.4% (95% CI, 1.5-19.4%) and 8.3% (95% CI, 0.2-16.4%), respectively. The results suggested that low-dose ATG/PTCy combined with CsA/MMF as GvHD prophylaxis in MUD-PBSCT had promising activity.