The role of umbilical cord blood transplantation (CBT) in acute myeloid leukemia (AML) patients with active disease at allogeneic hematopoietic cell transplantation (allo-HCT) remains poorly investigated. In this study, we compared transplantation outcomes of 2963 patients with primary refractory or relapsed AML given CBT, 10/10 HLA-matched UD, or 9/10 HLA-matched UD allo-HCT from 2004 to 2015 at EBMT-affiliated centers. Neutrophil engraftment and complete remission rates in CBT, UD 10/10, and UD 9/10 recipients were 75 and 48%, 93 and 69%, and 93 and 70%, respectively. In multivariate Cox analyses, in comparison with CBT (n = 285), UD 10/10 recipients (n = 2001) had a lower incidence of relapse (HR = 0.7, P = 0.001), a lower incidence of non relapse mortality (HR = 0.6, P < 0.001), better GVHD-free and leukemia-free survival (GRFS, HR = 0.8, P < 0.001) and better survival (HR = 0.6, P < 0.001). Further, in comparison with CBT, 9/10 UD recipients (n = 677) also had a lower incidence of relapse (HR = 0.8, P = 0.02), a lower incidence of nonrelapse mortality (HR = 0.7, P = 0.008), better GRFS (HR = 0.8, P = 0.01) and better survival (HR = 0.7, P < 0.001). In summary, these data suggest that in AML patients with active disease at transplantation, allo-HCT with UD results in better transplantation outcomes than CBT.
