Introduction
toxicity, AML, AML/MDS
ACUTE MYELOID LEUKEMIA, AML, HEMATOLOGIC MALIGNANCIES, REMISSION, RELAPSE
Relapse is the leading cause of treatment failure and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in hematologic malignancies. The cumulative incidence of relapse after allo-HSCT for acute myeloid leukemia (AML) can be as high as 40–50% with a long-term survival rate of only 10–15% [Increasing evidence suggests that chidamide, a benzamide-class histone deacetylase inhibitor (HDACI), is effective in AML. A pilot study showed that chidamide, fludarabine, and cytarabine combined with granulocyte colony-stimulating factor (G-CSF) (chidamide-FLAG) had a comparable complete remission (CR) rate (57.1%) and lower treatment-related mortality (TRM: 0%) than FLAG plus idarubicin or FLAG plus idarubicin and gemtuzumab ozogamicin (CR: 51%, TRM: 9%) in relapsed/refractory patients [Cytarabine plus aclarubicin and G-CSF (CAG) regimen has been proven successful in refractory and relapsed AML. Several mechanisms for its high efficacy have been proposed: (1) AML cells transition out of the G0 phase because G-CSF stimulation via cell surface receptors allows the other chemical agents to kill resting leukemic cells; (2) Priming with G-CSF effectively enhances cytarabine-induced apoptosis of AML cells; (3) The addition of G-CSF to the regimen enhances the ability of low doses of cytarabine to induce the differentiation of AML cells; (4) Aclarubicin is effective regardless of multi-drug resistance gene status [We hypothesized that chidamide plus the CAG regimen (CCAG) followed by DLI might boost the antitumor effect and reduce the toxicity of chemotherapy. Thus, we performed a phase II study to investigate the efficacy and safety of the CCAG regimen with DLI for patients with relapsed AML/MDS after allo-HSCT.