Chemotherapy (Decitabine in Combination With FLAG-Ida) and Total-Body Irradiation Followed by Donor Stem Cell Transplant for the Treatment of Adults With Myeloid Malignancies at High Risk of Relapse

Age ≥ 18 years with an HCT-co-morbidity index (CI) ≤ 5 for patients over 60 years.

AML (2022 World Health Organization [WHO] criteria) that is either primary refractory (as defined by failure of 2 cycles of 7+3-like chemotherapy, 1 cycle of high-dose cytarabine-based chemotherapy, or at least 2 cycles of venetoclax in combination with other therapies) or is in untreated or unsuccessfully treated first or subsequent relapse. Patients in morphologic remission (i.e. < 5% blasts in the bone marrow) but evidence of minimal residual disease (MRD) by multiparameter flow cytometry, cytogenetics/fluorescence in situ hybridization (FISH), or molecular means will be eligible for trial participation. Patients with relapsed or refractory acute leukemia of ambiguous lineage (acute undifferentiated leukemia or mixed phenotype acute leukemia) that is either primary refractory or is in untreated or unsuccessfully treated first or subsequent relapse are also eligible.

MDS and CMML: Subjects with previously treated MDS and CMML, defined as prior treatment with at least one hypomethylating agent (hypomethylating agent [HMA]; azacitidine, decitabine and/or decitabine-cedazuridine) whose disease progressed, relapsed, or was refractory to HMA treatment as follows: 1) patients who have failed at least 4 cycles of monotherapy with azacitidine, decitabine or decitabine-cedazuridine, 2) patients who received at least 2 cycles of HMA in combination with another therapeutic agent. Subjects with MDS and CMML who failed at least 1 cycle of induction chemotherapy will be also eligible. Patients with MDS or CMML who progress to secondary AML will be eligible if they received at least 4 cycles of HMA alone or 2 cycles of HMA in combination with another therapeutic agent.

Patients may have previously received hypomethylating agents or chemotherapy with a mitoxantrone, idarubicin- or cladribine/fludarabine-based regimen for MDS or AML. If the patient has received cladribine-cytarabine-filgrastim-mitoxantrone (CLAG-M) or FLAG-Ida before and has been sensitive to this regimen, defined as MRD negative complete remission (CR) immediately after receiving the treatment and which lasts ≥ 1 year, eligibility will be determined on a case-by-case basis by the study principal investigator (PI).