Chemotherapy, Total Body Irradiation, and Post-Transplant Cyclophosphamide in Reducing Rates of Graft Versus Host Disease in Patients With Hematologic Malignancies Undergoing Donor Stem Cell Transplant

This phase Ib/2 trial studies how well chemotherapy, total body irradiation, and post-transplant cyclophosphamide work in reducing rates of graft versus host disease in patients with hematologic malignancies undergoing a donor stem cell transplant. Drugs used in the chemotherapy, such as fludarabine phosphate and melphalan hydrochloride, 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. Giving chemotherapy and total-body irradiation before a donor stem cell transplant helps stop the growth of cells in the bone marrow, including normal blood-forming cells (stem cells) and cancer cells. When the healthy stem cells from a donor are infused into the patient, they may help the patient's bone marrow make stem cells, red blood cells, white blood cells, and platelets. Sometimes the transplanted cells from a donor can make an immune response against the body's normal cells (called graft versus host disease). Giving cyclophosphamide after the transplant may stop this from happening.