HLA-mismatched micro-transplantation as post-remission treatment compared to autologous hematopoietic stem cell transplantation or consolidation with single agent cytarabine for favorable-or intermediate-risk acute myeloid leukemia

Optimal post-remission treatment for individual favorable and intermediate risk acute myeloid leukemia (AML) patients has not yet been established. Human leukocyte antigen (HLA)-mismatched stem cell microtransplantation (MST), may improve outcomes and avoid graft-versus-host disease in patients with first complete remission of AML.We retrospectively analyzed the efficacy, safety, and survival of 63 patients with favorable- or intermediate-risk AML who received MST, autologous stem cell transplantation (ASCT), or cytarabine single agent (CSA) as post-remission treatment from January 2014 to August 2021.The neutrophil recovery time was shorter in the MST group than in the CSA group. The 2-year cumulative incidences of relapse in the MST, ASCT, and CSA groups were 27.27%, 29.41%, and 41.67%, respectively. During follow-up, 21 patients (33.30%) died of relapse, including six (9.52%), five (7.94%), and 10 (15.84%) in the MST, ASCT, and CSA groups, respectively. The estimated 2-year overall survival (OS) and relapse-free survival (RFS) were 62.20% vs. 50.00% (P = 0.101) and 57.10% vs. 50.00% (P = 0.136), in the >60 years MST and CSA groups (P = 0.101). The estimated 2-year OS was 100%, 66.20%, and 69.10% in the MST, ASCT, and CSA groups (MST vs CSA, P = 0.044), meanwhile, the estimated 2-year RFS was 100%, 65.40%, and 59.80% in patients ≤60 years.MST, ASCT, and CSA are acceptable post-remission treatments for patients with favorable- and intermediate-risk AML and may not only improve the prognosis of the elderly but also prolong the OS and RFS of favorable- or intermediate-risk patients ≤60 years.