Patients receive ifosfamide IV over 24 hours on days 1-4 and vinorelbine IV over 6-10 minutes on days 1 and 5. Patients also receive filgrastim (G-CSF) subcutaneously or IV over 15-30 minutes beginning 24-36 hours after completion of vinorelbine and continuing daily until blood counts recover. Treatment repeats at least every 21 days for 2 courses in the absence of disease progression or unacceptable toxicity. Patients may receive a third course of therapy at the discretion of the investigator.