Unique Reduced-Intensity Conditioning Haploidentical Peripheral Blood Stem Cell Transplantation Protocol for Patients with Hematologic Malignancy

•A unique reduced-intensity conditioning (RIC)-haploidentical (haplo)-high-dose peripheral blood stem cell transplantation (HDPSCT) protocol did not lead to a high incidence of acute graft-versus-host disease (GVHD).•The unique RIC-haplo-HDPSCT protocol was associated with improved engraftment and survival.•GVHD was reduced with the addition of basiliximab and dexamethasone. Reduced-intensity conditioning (RIC) haploidentical (haplo-) hematopoietic stem cell transplantation (HSCT) requires more hematopoietic progenitor and stem cells (HPSCs) to promote engraftment and immune reconstitution and needs a stronger graft-versus-leukemia effect. Peripheral blood stem cells (PBSCs) offer advantages over bone marrow; however, the use of higher-dose non-T cell-depleted (non-TCD) in vitro PBSCs may increase the occurrence of severe graft-versus-host disease (GVHD). This prospective, single-arm clinical study was performed to investigate using high-dose non-TCD in vitro PBSCs as the graft source, using fludarabine/Ara-C/busulfan (FAB) as the conditioning regimen, using rabbit antithymocyte globulin to remove T cells in vivo, and enhancing GVHD prophylaxis with an IL-2 receptor antagonist in RIC-haplo-HSCT in patients with hematologic malignancies age 50 to 70 years or