Gynecologic Oncology Group experience with ifosfamide.

In July 1985, the Gynecologic Oncology Group initiated a series of phase II trials with ifosfamide/mesna in advanced or recurrent gynecologic malignancies. Previously untreated patients received ifosfamide 1.5 g/m2/d intravenously (IV) for 5 days. Mesna was given IV every 4 hours for three doses after ifosfamide administration at a dose of 20% of the daily ifosfamide dose. All patients with ovarian cancer and 87% of those with cervical cancer had had prior 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/d in those who had had prior chemotherapy or radiotherapy. In epithelial ovarian carcinoma, responses were observed in eight (20%) of 41 evaluable patients, with three (7%) complete responses (CRs). Response duration was 2.1 to 20.3+ months (median, 6.9+ months). In squamous carcinoma of the cervix, 3 (11.1%) of 27 evaluable patients had partial responses (PRs) of 1.8-, 2.2-, and 3.1-month duration. Of 26 untreated patients with mixed mesodermal tumors of the uterus, 5 (19.2%) had CRs and 3 (11.5%) had PRs, for an overall response rate of 30.7%. Response duration was 1.4+ to 8.6 months, with a median of 3.8 months. Toxicity included two deaths from renal insufficiency and a third related to neurologic impairment. Hematologic toxicity was manageable. Ifosfamide/mesna has activity in a wide range of gynecologic malignancies.