- Filgrastim (G-CSF) and high-dose interleukin-2 (IL-2) therapy: Patients receive G-CSF subcutaneously (SC) daily beginning on day 0 and continuing until blood counts recover. Patients also receive high-dose IL-2 IV over 15 minutes 3 times daily on days 0-4 and 14-18. Patients are reevaluated 4-6 weeks after completion of high-dose IL-2 therapy. Patients achieving stable disease or a partial response may receive additional high-dose IL-2 as above for up to 2 retreatment courses in the absence of disease progression or unacceptable toxicity. Retreatment begins at least 6 weeks after autologous lymphocyte reinfusion.