The impact of pre-transplant minimal residual disease on outcome of intensified myeloablative cord blood transplant for acute myeloid leukemia in first or second complete remission

The impact of pretransplant minimal residual disease (MRD) on outcome of myeloablative cord blood transplant (CBT) for acute myeloid leukemia (AML) in complete remission (CR) has not been reported. Seventy-two AML patients were assessed for MRD before CBT, and the majority (84.7%) of these patients received single-unit CBT. All patients received intensified myeloablative conditioning with BUCY2 or TBICY plus high-dose cytarabine, and graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil. The cumulative incidences of neutrophil and platelet engraftment, acute or chronic GVHD were comparable between MRD-negative and MRD-positive groups. The cumulative incidence of transplant-related mortality (TRM) and relapse did not differ significantly between the two cohorts (25.6% vs. 32.5%, 16.1% vs. 19.2%; p=0.52, 0.61). There were no apparent differences in 3-year overall survival (OS) (68.9% in MRD-negative group and 57.9% in MRD-positive group, p=0.31) and 3-year leukemia-free survival (LFS) (62.5% in MRD-negative group and 52.7% in MRD-positive group, p=0.42) between both groups. The current study suggests that AML patients in morphological CR1 or CR2 who have detectable MRD might benefit from unrelated CBT with intensified myeloablative conditioning.