Alemtuzumab Plus Fludarabine and Melphalan With or Without Cyclosporine, Mycophenolate Mofetil, and Low-Dose Total-Body Irradiation Therapy Followed by Donor Peripheral Stem Cell Transplant in Treating Patients With Hematologic Cancer

OBJECTIVES: * Determine the ability of a reduced-intensity conditioning regimen comprising alemtuzumab, fludarabine, and melphalan with or without cyclosporine, mycophenolate mofetil, and low-dose total body radiotherapy followed by haplotype-mismatched, KIR class I epitope-mismatched CD34-positive allogeneic peripheral blood stem cell transplantation to facilitate engraftment by day 35 post-transplantation in at least 85% of patients with relapsed, refractory, or poor-risk hematological malignancies. * Determine the risk of graft-versus-host-disease in patients treated with these regimens. * Determine, preliminarily, the efficacy of these regimens, in terms of progression-free survival, in these patients. * Correlate outcomes, engraftment, and progression-free survival with the number of detectable alloreactive natural killer cell clones before transplantation and after engraftment in patients treated with these regimens. * Determine immune reconstitution in patients treated with these regimens. OUTLINE: This is a multicenter, pilot study. Patients are initially treated with conditioning regimen A. If adequate donor engraftment is not achieved, subsequent patients are treated with conditioning regimen B. * Conditioning regimen A: Patients receive alemtuzumab IV over 2 hours on days -14 to -12; fludarabine IV over 30 minutes on days -7 to -3; and melphalan IV over 20-30 minutes on day -2. * Conditioning regimen B: Patients receive oral or IV cyclosporine twice daily and oral or IV mycophenolate mofetil twice daily on days -15 to 0. Patients also receive alemtuzumab, fludarabine, and melphalan as in conditioning regimen A. Patients undergo low-dose total body irradiation twice daily on days -2 and -1. All patients undergo allogeneic, T-cell-depleted, CD34-positive peripheral blood stem cell transplantation on day 0. Patients receive sargramostim (GM-CSF) subcutaneously beginning on day 1 and continuing until blood counts recover. Patients are followed every 3 months for 1 year and then every 6 months for 5 years. PROJECTED ACCRUAL: A total of 14-56 patients (14-28 per regimen) will be accrued for this study.