Long-term, weekly one-hour infusion of paclitaxel in patients with metastatic breast cancer: a phase II monoinstitutional study.

Aims and Background: A dose-dense therapy with weekly paclitaxel given as a 1-hr infusion yielded a 53% overall response rate in breast cancer patients resistant to anthracyclines, with a remarkable lack of neutropenia (Seidman, 1998). We performed a monoinstitutional phase II trial in order to confirm these interesting results.
Patients and Methods: Eligibility criteria included advanced breast cancer and no taxane pretreatment. Paclitaxel was administered weekly at the dose of 90 mg/m2 (60 mg/m2 in patients at high risk of toxicity) by 1-hr i.v. infusion. Fifty-eight patients entered the trial. Median age was 54 years (range, 38-72). Performance status was good (median 1; range, 0-2). Fifty-two patients were pretreated with anthracyclines.
Results: A total of 1,004 weekly paclitaxel infusions were administered (median, 19 per patient; range, 4-43). The median delivered dose intensity was 67.4 mg/m2/week (range, 43-86). Twenty-eight of the 58 assessable patients obtained an objective response (48%), 15 had stable disease (26%) and 15 progressed (26%). The overall response rate was 48% (95% confidence interval, 35-61%) with 5 complete responses (8%). In anthracycline-pretreated patients, 23/52 (44%) responses were observed. Median duration of response was 5 months (range, 3-27). Toxicity was acceptable apart from a case of pulmonary embolism in a 70-year-old patient, 1 case of congestive heart failure in an anthracycline-pretreated patient aged 64, and 9 cases of G3 neutropenia. Peripheral neuropathy was observed in 38 patients (64%), usually of a mild grade; alopecia in 45 patients (78%) and onychopathy in 16 (28%), usually of a mild grade apart from 2 cases requiring treatment interruption. Tachycardia and atrial fibrillation occurred in a 55-year-old woman.
Conclusions: Our data seem to confirm the activity and safety of this approach even in a heavily pretreated population of patients. Its combination with other active drugs needs to be further investigated in clinical trials.