PHASE-II TRIAL OF FIRST-LINE HIGH-DOSE IFOSFAMIDE IN ADVANCED ADULT SOFT-TISSUE SARCOMA

Previous phase II trials using second-line high-dose ifosfamide (HD-IF S) in adult soft tissue sarcoma (STS) patients have reported a 20-35% remission rate after failure to previous standard-dose ifosfamide or c yclophosphamide. We here report on the use of HD-IFS in previously unt reated adult patients with unresectable STS in order to evaluate its a ctivity and toxicity as first-line therapy. Patients and methods: Thir ty-three adult patients suffering from previously untreated, unresecta ble high-grade STS were enrolled onto the study. HD-IFS was administer ed at a dosage of 15.4 g/m(2) over 6 days, followed by G-CSF on days 7 through 17. Results: HD-IFS resulted in low renal/metabolic toxicity and dose-limiting myelosuppression. Objective remissions were observed in 8 out of 30 evaluable patients (27%). Conclusion: This study provi des no evidence to support the hypothesis that HD-IFS at the dose and schedule administered in our study significantly increases the remissi on rate in previously untreated advanced adult STS beyond the results reported from numerous trials using IFS at lower doses (5-12 g/m(2)). We do not, therefore, recommend the administration of ifosfamide at do sages >12 g/m(2) outside of a controlled clinical trial.