Comparison of Single Unmanipulated Umbilical Cord Blood or Co-Infusion of an Umbilical Cord Blood Graft with CD34+ Cells From a Third Party Donor in Adults with Acute Leukemia

We compared the clinical outcomes of adults with acute leukemia that received single-unit umbilical cord blood transplantation (sUCBT) (n = 135) or stem cell transplant using co-infusion of an umbilical cord blood graft with CD34+ cells from a third party donor (Haplo-Cord) (n = 72) at different institutions within the Grupo Español de Trasplante Hematopoyético. In multivariable analysis, patients in the Haplo-Cord group showed more rapid neutrophil (HR 2.3; 95% confidence interval, 1.5-3.3; P < .001) and platelet recovery (HR 1.6; 95% confidence interval, 1.2-2.3; P = .015) and lower incidence of chronic GVHD (RR, .5; 95% confidence interval, .3-0.8; P = .01). Non-relapse mortality, relapse, disease-free survival (DFS) and GVHD-free/relapsed free survival were similar in the two groups. Regarding disease-specific outcomes, DFS in both acute myeloid leukemia and acute lymphoblastic leukemia (ALL) patients were not significantly different; however, a significantly higher relapse rate was found in patients with AML treated with Haplo-Cord (HR 2.3; 95% confidence interval, 1-5.4; P = .04). Our study demonstrates that Haplo-Cord was an effective strategy to fasten neutrophil and platelet recovery and that in the context these specific treatment platforms sUCBT and Haplo-Cord offer similar long-term outcomes.