Fludarabine, Total-Body Irradiation, and Donor Stem Cell Transplant Followed By Cyclosporine and Mycophenolate Mofetil in Treating Patients With Chronic Myelogenous Leukemia

RATIONALE: Giving low doses of chemotherapy, such as fludarabine, and radiation therapy before a donor stem cell transplant helps stop the growth of cancer cells. It also stops the patient's immune system from rejecting the donor's stem cells. The donated stem cells may replace the patient's immune system and help destroy any remaining cancer cells (graft-versus-tumor effect). Sometimes the transplanted cells from a donor can also make an immune response against the body's normal cells. Giving cyclosporine and mycophenolate mofetil after transplant may stop this from happening. PURPOSE: This phase I/II trial is studying the side effects and best dose of fludarabine, total-body irradiation, and donor stem cell transplant followed by cyclosporine and mycophenolate mofetil and to see how well they work in treating patients with chronic myelogenous leukemia.