T Cell Depleted Allogeneic Hematopoietic Stem Cell Transplantation Conditioned With a Reduced Intensity Regimen in Patients With Hematologic Malignancies and Aplastic Anemia

The main purpose of this study is to learn if a new combination of chemotherapy, in combination with low-dose radiation, will be safe for the patient, and at the same time provide the best opportunity to cure the bone marrow cancer. The combination of chemotherapy and radiation described in the study is considered 'low intensity.' Although the chemotherapy agents used in this study and for transplant are FDA approved, the chemotherapy treatment and conditioning regimens or combinations listed in this consent are not yet FDA approved. The CliniMACS device is FDA approved for one type of T cell depletion (positive selection of the stem cells) but not approved yet for other type of T cell depletion, which is being studied on this protocol. This pilot study, along with other studies will serve as the basis for FDA approval, if outcomes are favorable.