Decitabine Combination Therapy Pre-ASCT

This phase I/II trial studies the safety, side effects, and best dose of decitabine in combination with fludarabine, cytarabine, filgrastim, and idarubicin (FLAG-Ida) and total body irradiation (TBI) followed by a donor stem cell transplant in treating adult patients with cancers of blood-forming cells of the bone marrow (myeloid malignancies) that are at high risk of coming back after treatment (relapse). Cancers eligible for this trial are acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and chronic myelomonocytic leukemia (CMML). Decitabine is in a class of medications called hypomethylation agents. It works by helping the bone marrow produce normal blood cells and by killing abnormal cells in the bone marrow. The FLAG-Ida regimen consists of the following drugs: fludarabine, cytarabine, filgrastim, and idarubicin. These are chemotherapy drugs that work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Filgrastim is in a class of medications called colony-stimulating factors. It works by helping the body make more neutrophils, a type of white blood cell. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. TBI is radiation therapy to the entire body. Giving chemotherapy and TBI before a donor peripheral blood stem cell (PBSC) transplant helps kill cancer cells in the body and helps make room in the patient's bone marrow for new blood-forming cells (stem cells) to grow. When the healthy stem cells from a donor are infused into a patient, they may help the patient's bone marrow make more healthy cells and platelets. Giving decitabine in combination with FLAG-Ida and TBI before donor PBSC transplant may work better than FLAG-Ida and TBI alone in treating adult patients with myeloid malignancies at high risk of relapse.