PHASE I/II TRIAL OF SEQUENTIAL TAXOL/IFOSFAMIDE AND DOSEINTENSIVE CARBOPLATIN/ETOPOSIDE WITH STEM CELL SUPPORT IN CISPLATIN-RESISTANT GERM CELL TUMOR PATIENTS WITH UNFAVORABLE PROGNOSTIC FEATURES

OBJECTIVES: Determine the safety of paclitaxel and ifosfamide followed by carboplatin and etoposide with stem cell support in patients with unfavorable germ cell tumors with unfavorable prognostic factors and resistance to cisplatin. Determine the efficacy of this regimen as salvage therapy in these patients. Escalate the dose of carboplatin based on a target area under the concentration time curve and renal function, and determine the pharmacokinetics of carboplatin in selected patients. Determine the qualitative effects of paclitaxel and ifosfamide on hematopoietic progenitors in these patients. OUTLINE: This is a dose escalation study of carboplatin. Part A: Patients receive paclitaxel IV continuously on day 1 and ifosfamide IV over 4 hours on days 2-4. Autologous peripheral blood stem cells (PBSC) are harvested on days 11-13. Filgrastim (G-CSF) is administered subcutaneously (SC) twice daily beginning 6 hours after completion of paclitaxel and ifosfamide infusions and continuing until the last day of leukapheresis. Treatment continues every 2 weeks for 2 courses in the absence of disease progression or unacceptable toxicity. Before beginning the first course of chemotherapy, autologous bone marrow (ABM) is harvested, if possible, in case insufficient peripheral blood stem cells (PBSC) are harvested. Patients who were unable to undergo harvest of ABM before the first course of chemotherapy undergo harvest of ABM before beginning the second course of chemotherapy. Part B : Beginning 2 weeks after completion of regimen A, patients receive etoposide IV over 2 hours and carboplatin IV over 1 hour on days 1-3. PBSC are reinfused on day 5. G-CSF is administered SC twice daily beginning 6 hours after completion of etoposide and carboplatin infusions and continuing until blood counts recover. G-CSF is held on the morning of PBSC transplantation and restarted beginning 6 hours after completion of PBSC transplantation. Treatment continues every 2 weeks for 3 courses in the absence of disease progression or unacceptable toxicity. Patients with insufficient PBSC for the second course receive PBSC combined with ABM. Patients with insufficient PBSC for the third course receive ABM. During the second part, cohorts of 3-6 patients receive escalating doses of carboplatin until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 3 of 6 patients experience dose-limiting toxicity. After completion of parts A and B, some patients may undergo resection of residual masses.