 - Reduced-intensity conditioning regimen: Patients receive fludarabine phosphate IV over 1 hour on days -10 to -6, busulfan IV over 2 hours once on day -10 test dose and then every 6 hours on days -5 and -4, and anti-thymocyte globulin IV over 6-8 hours on days -3 to -1 and on day 2. 