A novel intensive conditioning regimen for allogeneic hematopoietic stem cell transplantation in the treatment of relapsed/refractory acute myeloid leukemia.

We conducted a prospective study to evaluate the efficacy and safety of cladribine, cytarabine, mitoxantrone, and granulocyte colony-stimulating factor (CLAG-M) regimen combined with busulfan and cyclophosphamide (BuCy) as new intensive conditioning before allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of relapsed/refractory acute myeloid leukemia (AML). 24 patients were enrolled. The median follow-up was 15.2 months (range 1.9-67.0 months). Except for one patient who died before graft infusion, the evaluable 23 patients (96%) achieved complete remission (CR). The two-year overall survival (OS) rate and leukemia-free survival (LFS) rate were 61.4% and 59.4%, respectively. The non-relapse mortality (NRM) was 9.1%. Univariate analysis revealed that the myeloid blast phase of chronic myelomonocytic leukemia (CMML), an EVI1 mutated, blood blasts ≥20% at transplant, and extramedullary disease were risk factors for LFS.