Study Comparing Reduced Versus Standard Dose Post-transplantation Cyclophosphamide in Combination With Post-engraftment Anti-thymoglobin as Graft Versus Host Disease Prophylaxis in Alternative Donor Peripheral Stem Cell Transplantation

This is a multi-center randomized study in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) from alternative donors (9-10/10 matched unrelated donor or haplo-identical donors). The aim is to evaluate to the efficacy and feasibly of reduced-dose of PTCY at 35mg/kg as GVHD prophylaxis. Patients will be assigned to study group receiving PTCy at 35mg/kg on day +3 and +4 together with tacrolimus starting from day +5 and single dose anti-thymoglobin at 2.5mg/kg as GVHD prophylaxis or to the control group with standard dose of PTCY at 50mg/kg on day +3 and +4 with same dose of tacrolimus and ATG as the study group.