At least 1 month after interferon is stopped, mobilization chemotherapy is administered. Patients receive cyclophosphamide IV over 12 hours on day 0, etoposide IV over 2 hours on day 1, sargramostim (GM-CSF) SC on days 3 and 4, and filgrastim (G-CSF) SC beginning on day 5. Peripheral blood stem cells (PBSC) are collected by leukapheresis when blood cell counts have recovered.