Donor Type Does Not Impact Late Graft Failure Following Reduced Intensity Allogeneic Hematopoietic Cell Transplantation with Post-Transplant Cyclophosphamide Based Graft-Versus-Host Disease Prophylaxis.

Background: Post-transplant cyclophosphamide (PTCy) is a commonly used graft-vs-host disease (GVHD) prophylaxis, particularly in the setting of haploidentical (haplo) hematopoietic cell transplantation (HCT). The rate of graft failure has been reported to be as high as 12-20% in haplo-HCT recipients using PTCy. The objective of this study was to determine if donor type influenced the risk of late graft failure following RIC HCT using PTCy-based GVHD prophylaxis.