A PHASE-II STUDY OF DOCETAXEL IN PATIENTS WITH PACLITAXEL-RESISTANT METASTATIC BREAST-CANCER

Purpose: To evaluate the efficacy and safety of docetaxel in patients with paclitaxel-resistant metastatic breast cancer (MBC). Patients and Methods: Docetaxel (100 mg/m(2)) was administered every 3 weeks to 46 patients registered at four centers. Patients had previously received less than or equal to two chemotherapy regimens for MBC, All patients had progressive disease while receiving paclitaxel therapy, Treatment was repeated until there was evidence of disease progression or for a maximum of three cycles after best response. Results: Objective respo nses were seen in eight of 44 assessable patients (18.1%; 95% confiden ce interval [CI], 6.7% to 29.5%), Seven patients had partial responses and one patient responded completely Response rates were not signific antly different by previously received paclitaxel dose or resistance. No responses were seen in 12 patients who had previously received pacl itaxel by 24-hour infusion, but the response rate in 32 patients who h ad received paclitaxel by 1- to 3-hour infusion was 25%, The median re sponse duration was 29 weeks and the median time to disease progressio n was 10 weeks. Median survival was 10.5 months. Clinically significan t (severe) adverse events included neutropenic fever (24% of patients) , asthenia (22%), infection (13%), stomatitis (9%), neurosensory chang es (7%), myalgia (7%), and diarrhea (7%). Conclusion: Docetaxel is act ive in patients with paclitaxel-resistant breast cancer, particularly in those who failed to respond to brief infusions of paclitaxel. Respo nse rates were comparable to or better than those seen with other ther apies for patients with paclitaxel-resistant MBC, This confirms precli nical studies, which indicated only partial cross-resistance between p aclitaxel and docetaxel. (C) 1998 by American Society of Clinical Onco logy.