- Reduced-intensity conditioning (RIC): Patients receive anti-thymocyte globulin IV over 4-6 hours on day -16 and over 6-8 hours on day -15, fludarabine phosphate IV over 30 minutes on days -7 to -3, busulfan IV over 3 hours on days -4 and -3, and cyclophosphamide IV over 1-2 hours on day -2.