High-Dose Chemotherapy Followed by Total-Body Irradiation and Peripheral Stem Cell Transplantation in Treating Patients With Chronic Lymphocytic Leukemia

OBJECTIVES: I. Evaluate engraftment after autografting with CD34 selected peripheral blood stem cells (PBSC) in patients with chronic lymphocytic leukemia (CLL). II. Evaluate the efficacy of CD34 selection for purging CLL from PBSC collection. III. Determine the effectiveness of mobilization chemotherapy with cyclophosphamide, etoposide, and dexamethasone plus filgrastim (granulocyte colony-stimulating factor) to mobilize PBSC in these patients. IV. Describe toxicity and disease response to a conditioning regimen of total body irradiation and cyclophosphamide in these patients. OUTLINE: There are 3 phases to the treatment plan: Cytoreductive chemotherapy can be given by conventional chemotherapy. Patients are treated until at least a good partial remission. Patients will have CD34 selected peripheral blood stem cells (PBSC) stored after treatment with mobilization chemotherapy followed by filgrastim (granulocyte colony-stimulating factor; G-CSF). Cyclosphosphamide (CTX) IV is given over 1 hour. Etoposide (VP-16) is given over 1-2 hours on day 2. Dexamethasone is given 4 times a day on days 1-3. G-CSF is given subcutaneously daily beginning 2 days after chemotherapy and continuing until PBSC collection is completed. At least 4 weeks should ensue after mobilization chemotherapy before proceeding with the transplant. Patients are treated with TBI on days -6, -5, and -4 and CTX on days -3 and -2. PBSC are infused on day 0. PROJECTED ACCRUAL: A total of 15 patients will be entered in this study.