Phase II study of paclitaxel (BMS-181339) intravenously infused over 3 hours for advanced or metastatic breast cancer in Japan

A Phase II study of paclitaxel in patients with primary advanced or metastatic breast cancer was conducted by a cooperative study group consisting of 16 institutions in Japan. Paclitaxel at a dose of 210 mg/m(2) was intravenously infused over 3 hours, along with premedication to prevent hypersensitivity reactions. The course was repeated at 21-day intervals. Of 62 eligible patients, 60 were evaluable for toxicity and 59 were evaluable for efficacy. Forty-five patients were previously treated with anthracyclines. Twenty-one of 59 patients (35.6%) had a major objective response including 2 CRs and 19 PRs (95% confidence interval, 23.6-49.1%). A response rate of 35.5% (CR1, PR10) was observed in 31 patients refractory to the anthracyclines containing prior metastatic chemotherapy. Median (range) rime was 41 (6-100) days to onset of and median duration of response was 125 (36-305) days. Toxicities included leukopenia (grade 3, 4: 67%), anemia (grade 1-3, 80%), thrombocytopenia (grade 1: 8%), alopecia (grade 3: 43%), peripheral neuropathy (grade 1-3. 93%), arthralgia (59%), myalgia (46%), nausea and vomiting (40%), fever (33%), allergic reaction (grade 3. 2%) and hypotension (grade 3: 5%). All toxicities were tolerable and manageable. Paclitaxel intravenously infused over 3 hours demonstrated a significant antitumor activity for metastatic breast cancer. Furthermore, paclitaxel exhibited non-cross resistance to anthracycline. Paclitaxel administered as a convenient 3-hour infusion is effective for patients with metastatic breast cancer and has an acceptable toxicity profile.