Ifosfamide bolus followed by five days continuous infusion in extensively pretreated patients with advanced breast cancer: a phase II study.

Purpose: A phase II study with ifosfamide in pretreated patients with advanced breast cancer was performed to determine the objective response rate, the toxicity and the feasibility of the regimen.
Methods & Study Design: Patients enrolled had advanced breast cancer pretreated with at least one previous regimen of chemotherapy for advanced disease. Treatment consisted of ifosfamide infused at a dose of 2 g/m2 iv in 4 hrs followed by ifosfamide, 8 g/m2 iv in 120 hrs in ambulatory treatment, using a portable external pump system. The total dose of ifosfamide was 10 g/m2; mesna (4 g/m2 iv) was administered mixed with ifosfamide in 120 hrs Cycles were repeated every 3 weeks. Three patients were pretreated with neoadjuvant and 15 with adjuvant chemotherapy. All patients were treated for advanced disease (median number of regimens, 1; range, 1-3): 21 with the cyclophosphamide-containing regimen and 15 with adryamicin. Sixteen patients received one or more lines of endocrine therapy. Fifteen patients had dominant site in viscera, 6 in bone, and only one in soft tissue; 17 patients had more than one site of disease.
Results: Twenty-two patients were enrolled and all were assessable for response and toxicity. A partial response was reached in 5 patients (23%; 95% confidence limits 5% to 60%). Hematologic toxicity was the dose-limiting side effect; grade 4 leukopenia occurred in 10 patients (46%).
Conclusions: Considering the response rate obtained in our series of intensively pretreated patients, the results seem to indicate that the regimen is active and could be included among the possible options in the treatment of patients with refractory, poor-prognosis, advanced breast carcinoma.