Clinical evaluation of conditioning regimen containing idarabicin (IDA) for refractory/recurrent acute leukemia by allogeneic hematopoietic stem cell transplantation

Objective To evaluate the therapeutic effects of conditioning regimen containing idarabicin (IDA) for refractory/recurrent leukemia. Method From June 2012 to August 2014, 21 patients with refractory/recurrent leukemia were enrolled, including 8 cases of acute lymphoblastic leukemia (ALL), 12 cases of acute myeloid leukemia (AML) and 1 case of chronic myelogenous leukemia-blastic phase (CML-BP). Eighteen of them received HLA-haplo-identical stem cells transplantation (HSCT) from parent or sibling donors. Two patients underwent HLA identical allo-HSCT and one received cord blood transplantation. Conditioning regiments consisted of idarubicin/total body irradiation/ara with fludarabine and granulocyte colony-stimulating factor (IDA/TBI/FLAG), IDA/ busulfan and cytoxan (BuCy), IDA/TBI/Cy, and IDA/FLAG that followed by reduced-intensified BuCy. Result All 21 patients but 1 achieved stable engraftment. The median time of neutrophils≥0.5×109/L was 17 (11-28) days. And for platelet≥20×109/L, the median was 22 (8-70) days. Seven patients developed acute graft-versus-host disease (GVHD), and the accumulative incidence of acute GVHD (aGVHD) was (33.3±5.6)%. Five patients developed Ⅱ-Ⅳ grade of aGVHD, and the accumulative incidence was (23.8±4.8)%. Among 21 evaluable patients, 11 patients developed chronic GVHD (cGVHD) (10 patients extensive, and 1 patients limited), and the accumulative incidence of cGVHD was (67.9±2.2)%, and for extensive type, the accumulative incidence was (65.7±2.2)%. The median follow-up time post transplantation was 14 (3-26) months. Four patients relapsed and the accumulative incidence of relapse was (23.5±1.9)%. Sixteen patients survived and the overall survival (OS) and disease-free survival (DFS) were (72.8±1.8)% and (56.1±2.1)%, respectively. Conclusion Our clinical results suggested that the combination of salvaged HSCT and prophylactic immunotherapy is a promising modality for treatment of refractory/recurrent leukemia, even with high leukemia burden. Key words: Idarabicin; Leukemia; Recurrence; Refractory; Hematopoietic stem cell transplantation