Alternative donor transplantation for myelodysplastic syndromes: haploidentical relative and matched unrelated donors

We compared outcomes in 603 patients with myelodysplastic syndrome (MDS) after HLA HLA: See human leukocyte antigen. -haploidentical relative (n = 176) and HLA-matched unrelated (n = 427) donor hematopoietic cell transplantation (HCT) from 2012 to 2017, using the Center for International Blood and Marrow Transplant Research database. All transplantations used reduced-intensity conditioning regimens. Total-body irradiation plus cyclophosphamide cyclophosphamide: Cyclophosphamide is in a class of medications called alkylating agents. When used to treat cancer, it works by slowing or stopping the growth of cancer cells in your body. When cyclophosphamide is used to treat bone marrow failure, it works by suppressing your body's immune system. and fludarabine fludarabine: The U.S. Food and Drug Administration (FDA) approved fludarabine for treating chronic lymphocytic leukemia (CCL). Researchers are studying fludarabine in combination with other medicines for treating bone marrow failure. was the predominant regimen for HLA-haploidentical relative donor HCT, and graft-versus-host disease (GVHD) graft-versus-host disease (GVHD): Also called GVHD, it is a common complication of bone marrow/stem cell transplantation. It is caused when the donor's immune cells, now in the patient, begin to see the the patient's body as foreign and mount an immune response. GVHD most commonly effects the recipient's skin, intestines, or liver… prophylaxis was uniformly posttransplantation cyclophosphamide, calcineurin inhibitor, and mycophenolate. Fludarabine with busulfan or melphalan was the predominant regimen for HLA-matched unrelated donor unrelated donor: A donor that is not a sibling or other familial relation of the patient (recipient). HCT, and GVHD prophylaxis was calcineurin inhibitor with mycophenolate or methotrexate. Results of multivariate analysis revealed higher relapse (hazard ratio [HR], 1.56; P = .0055; 2-year relapse rate, 48% vs 33%) and lower disease-free survival (DFS) rates after HLA-haploidentical relative donor HCT (HR, 1.29; P = .042; 2-year DFS, 29% vs 36%). However, overall survival (OS) rates did not differ between donor type (HR, 0.94; P = .65; 2-year OS, 46% for HLA-haploidentical and 44% for HLA-matched unrelated donor HCT) because of mortality associated with chronic GVHD. Acute grade 2 to 4 GVHD (HR, 0.44; P < .0001) and chronic GVHD (HR, 0.36; P < .0001) were lower after HLA-haploidentical relative donor HCT. By 2 years, probability of death resulting from chronic GVHD was lower after HLA-haploidentical relative compared with HLA-matched unrelated donor HCT (6% vs 21%), negating any potential survival advantage from better relapse control. Both donor types extend access to transplantation for patients with MDS; strategies for better relapse control are desirable for HLA-haploidentical relative donor HCT, and effective GVHD prophylaxis regimens are needed for unrelated donor HCT.