Early phase II Gynecologic Oncology Group experience with ifosfamide/mesna in gynecologic malignancies

Starting in July 1985, the Gynecologic Oncology Group conducted a series of phase II trials with ifosfamide/mesna in advanced or recurrent gynecologic malignancies. Previously untreated patients received 1.5 g/m2 i.v. ifosfamide daily for 5 days. Mesna was given i.v. q4h x 3 following ifosfamide; each dose was 20% of the daily ifosfamide dose. All patients with ovarian and 87% of those with cervical cancer had previously undergone platinum-based therapy. Because of the toxicity encountered in previously treated patients with ovarian carcinoma, the dose of ifosfamide was reduced to 1.2 g/m2 daily in all patients who had received prior chemo- or radiotherapy. In epithelial ovarian carcinoma, responses were observed in 8 (20.0%) of 41 evaluable patients, with 3 (7.0%) complete responses. Response duration was 2.1-20.3+ months, with a median of 6.9+ months. In squamous-cell carcinoma of the cervix, 3 (11.1%) of 27 evaluable patients showed partial responses of 1.8, 2.2, and 3.1 months' duration. Of 26 untreated patients with mixed mesodermal tumors of the uterus, 5 (19.2%) achieved complete and 3 (11.5%) showed partial responses, for an overall response rate of 30.7%. Response duration was 1.4(+)-8.6 months, with a median of 3.8 months. Toxicity included two deaths due to renal insufficiency and a third related to neurologic impairment. Hematologic toxicity was manageable. Ifosfamide/mesna has activity in a wide range of gynecologic malignancies.