Multicenter phase II trial of weekly paclitaxel in women with metastatic breast cancer

Purpose We evaluated the safety and efficacy of weekly paclitaxel therapy i n women with metastatic breast cancer in a phase II multicenter trial. Entr y criteria were relatively liberal to reflect the heterogeneity of metastat ic breast cancer in clinical practice. Patients and Methods: Patients had histologically confirmed and measurable metastatic breast cancer. Up to two prior chemotherapy regimens for metasta tic disease, including prior therapy with anthracyclines and taxanes and pr ior high-dose therapy, were allowed. Paclitaxel 80 mg/m(2) was administered weekly for 4 weeks per 4-week cycle. Results: We enrolled 212 patients, 211 were assessable for toxicity and 177 were assessable for response. Ninety percent of patients had received prio r chemotherapy (adjuvant, metastatic, or both), 46% of patients had three o r more involved metastatic sites, and 60% of patients had visceral-dominant disease. Responses were documented on two occasions and were independently reviewed. The overall response rate (complete plus partial response) was 2 1.5% (95% confidence interval, 15.4% to 27.5%), with 41.8% of patients havi ng disease stabilization. Median time to progression was 4.7 months, and ov erall survival in all 212 patients enrolled was 12.8 months. Therapy was we ll tolerated, with a 15% incidence of grade 3/4 hematologic toxicity and a, 9% incidence of grade 3 neurotoxicity; other serious toxicities were rare. The response rate and toxicity profile in the 34% of patients greater than or equal to 65 years of age were similar to that of younger patients. Conclusion: Weekly paclitaxel therapy was well tolerated and demonstrated r easonable activity in this relatively heavily pretreated population with ad vanced disease. Further study of weekly paclitaxel, in combination therapy is warranted. (C) 2001 by American Society of Clinical Oncology.