A phase II study of ifosfamide/mesna with doxorubicin for adult soft tissue sarcoma

In a phase II study, 16 adult patients with locally advanced or metastatic soft tissue sarcomas were treated with i.v. infusions of ifosfamide/mesna 5 g/m2 plus i.v. doxorubicin 40 mg/m2. Courses were given every 3 weeks up to a maximum of six courses in responding patients. Six patients (37.5%) had either complete (1 patient) or partial responses (5 patients). Confidence limits for this response rate were 15.2%-64.5% (95% confidence level). There was one toxic death in association with encephalopathy, renal and bone marrow failure. Unilateral pneumothoraces occurred in 2 patients with large pulmonary metastases. Recurrent severe ifosfamide/mesna encephalopathy occurred in 2 patients at risk for this complication; patients who develop severe ifosfamide/mesna encephalopathy should not be retreated with this drug. Ifosfamide/mesna with doxorubicin is an active combination to treat adult soft tissue sarcoma but, despite the feasibility of the combination, sequential monotherapy with these drugs might provide similar or better clinical benefit.