Outcome of human umbilical cord blood stem cell transplantation (CBT) for acute myeloid leukemia in patients achieving first complete remission after one versus two induction courses: a study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT).

We compared transplantation outcomes of adult patients with AML that underwent cord blood transplantation (CBT) in CR1 following 1 versus 2 induction courses. Study included 325 patients, 243 (75%) with 1 and 82 (25%) with 2 induction courses. Engraftment was lower for patients achieving CR1 after 1 vs. 2 induction courses: 91% vs. 99% (p = 0.02). Incidence of acute GVHD was similar, 38% and 36% (p = 0.81), as was 2-year chronic GVHD at 23.4% and 27.5%, respectively (p = 0.65). Two-year non-relapse mortality (NRM), relapse incidence (RI), leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) were not statistically different between patients achieving CR1 with 1 vs. 2 induction courses with 23% vs. 24% (p = 0.87), 25% vs. 30% (p = 0.4), 52% vs. 46% (p = 0.3), 59% vs. 50% (p = 0.2), and 44% vs. 41% (p = 0.66), respectively. Results were confirmed by multivariable analysis, NRM (hazard ratio (HR) = 1.1; 95% CI, 0.6-1.8, p = 0.7), RI (HR = 1.4; 95% CI, 0.9-2.3, p = 0.1), LFS (HR = 1.3; 95% CI, 0.9-1.8, p = 0.2), OS (HR = 1.3; 95% CI, 0.9-1.9, p = 0.1), and GRFS (HR = 1.1; 95% CI, 0.8-1.5, p = 0.5). Overall, outcomes of AML patients undergoing CBT in CR1 achieved after 1 or 2 induction courses are similar.