Expert Consensus on Microtransplant for Acute Myeloid Leukemia in Elderly Patients -Report From the International Microtransplant Interest Group

Recent studies have shown that microtransplant (MST) could improve outcome of patients with elderly acute myeloid leukemia (EAML). To further standardize the MST therapy and improve outcomes in EAML patients, based on analysis of the literature on MST, especially MST with EAML from January 1st, 2011 to November 30th, 2022, the International Microtransplant Interest Group provides recommendations and considerations for MST in the treatment of EAML. Four major issues related to MST for treating EAML were addressed: therapeutic principle of MST (1), candidates for MST (2), induction chemotherapy regimens (3), and post-remission therapy based on MST (4). Others included donor screening, infusion of donor cells, laboratory examinations, and complications of treatment

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

ABSTRACTObjectives 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.Methods 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.Results 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.Conclusion 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