- Arm I: Within 1 month after PBSC collection, patients receive conditioning comprising busulfan IV every 6 hours on days -7 to -4 and cyclophosphamide IV over 2 hours on days -3 and -2. Patients then undergo autologous PBSC transplantation on day 0. Patients receive sargramostim (GM-CSF) or G-CSF IV or SC beginning on day 0 and continuing until blood counts recover.