- Arm I: In the priming phase, patients receive cyclophosphamide IV over 2 hours on day 1, mitoxantrone IV over 1 hour daily on days 1-2, and dexamethasone IV every 12 hours beginning on day 1 for a total of 4 doses. Patients also receive sargramostim (GM-CSF) IV over 2 hours or subcutaneously (SC) daily beginning 48 hours after the last dose of mitoxantrone and continuing until completion of leukapheresis. Peripheral blood stem cells (PBSC) are collected daily on days 11-13 after neutrophil recovery.