- Arm II: Patients receive treatment as in arm I. Patients also receive interleukin 2 (IL-2) IV continuously on days 1-4 and interferon alfa-2b subcutaneously (SC) daily before IL-2 on days 1-4 and after IL-2 on day 5, followed by filgrastim (G-CSF) (SC) daily on days 7-16.