Trial of 2 Step ATG for Prevention of Acute GVHD Post Allogeneic Stem Cell Transplant

In an effort to reduce graft versus host disease (GVHD) and enhance graft versus leukemia (GVL) effect post allogenic hematopoietic stem cell transplantation (AHSCT), recent research has focused on host immune cell depletion. Frame shifting anti-thymocyte globulin (ATG) backwards to earlier days before days 0 can result in deeper host and less graft T-cell depletion, leading to better immune reconstitution. Preliminary data where 80% of the ATG dose is given on days -6,-5,-4 and 20% given on day -1, showed effective prevention of severe acute GVHD, chronic GVHD and favorable early immune reconstitution. We hypothesize that our 2 step ATG dosing platform when combined with standard tacrolimus and mini methotrexate can prevent grade III-IV acute GVHD and chronic GVHD, resulting in improvement of GVHD/relapse free survival at one year post transplant.