Alloreactive NK Cells for Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS)

NK cells are part of the immune system (the cells in your body that fight disease). Sometimes, NK cells react against and fight leukemia cells that are mismatched with your body for certain HLA tissue type proteins. When the NK cells react, these cells are called "alloreactive NK cells." In this study, researchers will collect alloreactive NK cells from the blood of a relative of yours whose HLA proteins do not match yours exactly. The NK cells are separated from the blood using a machine called a CLINIMACs system. This machine uses special kinds of cells and magnetic beads to separate the NK cells. The drug interleukin-2 is then added to the NK cells, to improve their function. The interleukin-2 will be washed out of the cell sample before it is given to you. The CliniMACS System is a medical device that is used to separate types of blood cells from blood that is removed from the body during leukapheresis. These separated cells are processed for use in treatments such as stem cell transplants. If you are able to take part in this study, you will receive high-dose chemotherapy for 4 days. You will receive fludarabine over about 30 minutes daily as an intravenous (IV--through a needle in your vein) infusion . You will also receive busulfan over 3 hours by IV once a day. About 2 days later, you will be given the infusion of the alloreactive NK cells by IV. Patients will receive one of 3 dose levels. Some patients will receive interleukin-2 daily for 4 days to enhance the function of the NK cells. Five (5) days after the NK cell infusion, thymoglobulin will be given to you by IV daily for 3 days. Thymoglobulin is an immunosuppressive treatment to reduce the risk of graft rejection. Then blood stem cells will be administered IV from a different stem cell donor whose HLA type matches yours. You will receive the drugs tacrolimus and methotrexate to help lower the risk of a reaction called "graft-vs.-host disease" (GVHD). GVHD is when the donated immune cells in the transplant react against the body of the person receiving the cells. Tacrolimus will be given by IV for about 2 weeks, and after that it is given by mouth as a pill for at least 3 months. Methotrexate will be given as an IV injection for 3 to 4 doses over the first 11 days after the stem cell transplant. You will also receive the drug G-CSF (Neupogen) as an injection under the skin until your blood cell counts reach a certain high enough level. You will need to stay in the hospital for about 4 weeks. After you leave the hospital, you will continue as an outpatient in the hospital area, which means you will have to stay close enough to be able to come back for any visits for at least 100 days after the transplant. You will be asked to come back to the clinic at 3, 6, and 12 months after your transplant for routine safety testing. This will include a physical exam, a bone marrow biopsy, and routine blood draws. This is an investigational study. The way the researchers make the alloreactive NK cells using the CLINIMACs device is investigational. The CliniMACS device is not FDA approved. At this time, it is being used in research only. Up to 18 patients will take part in this study.