Post-transplant cyclophosphamide versus antithymocyte globulin as GVHD prophylaxis for 10/10 HLA-matched unrelated allogeneic hematopoietic stem cell transplantation

After T-cell replete haploidentical stem cell transplantation, GVHD prophylaxis with post-transplant cyclophosphamide (PT-Cy) is now evaluated in unrelated donor (UD) transplants, where antithymocyte globulin (ATG) remains standard. We report the outcome of patients transplanted from HLA-10/10 matched unrelated donor (MUD) treated with PT-Cy (n=30), in comparison with a historical cohort treated with ATG (n=64). In the PT-Cy group, we observed lower 2-4 acute GVHD (23% vs. 45%, p=0.014), lower chronic GVHD (all grades: 13% vs 33%, p=0.029; moderate to severe: 10% vs. 27%, p=0.039) but no difference in the relapse (20% vs. 11%, p=0.628), non-relapse mortality (3% vs 11%, p=0.169), progression free survival (77% vs 78%, p=0.638) and overall survival (87% vs 83%, p=0.602). Neutrophil (19 vs 17 days, p=0.049) and platelet (26 vs 10 days, p