Phase 3 study comparing the use of docetaxel on an every-3-week versus weekly schedule in the treatment of metastatic breast cancer

BACKGROUND. Previous studies have evaluated 3-week and weekly docetaxel schedules in patients with metastatic breast cancer (MBC). The varying efficacy results and toxicity profiles noted in these earlier studies led to a comparison of the schedules to determine which was safer and more efficacious. METHODS. A phase 3 clinical trial was conducted in patients with MBC who were treated with docetaxel either every 3 weeks or once weekly to determine and compare response rate and duration, time to disease progression, progression-free survival (PFS), overall survival (OS), and toxicity. Patients were randomized to receive docetaxel at a starting dose of either 75 mg/m² every 3 weeks or 35 mg/m² weekly for 3 consecutive weeks followed by 1 week of rest. RESULTS. A total of 118 patients underwent efficacy analysis; 59 patients were randomized to the every-3-week treatment arm and 59 to the weekly arm. The response rate was 35.6% (95% confidence interval [95% CI], 23.6-49.1%) for the every-3-week arm versus 20.3% (95% CI, 11.0-32.8%) for the weekly arm. There was no statistical difference between the every 3-week and the weekly treatment arms with regard to median PFS (5.7 months vs 5.5 months; P = .46) or OS (18.3 months vs 18.6 months, respectively; P = .34). There was a higher overall toxicity rate (grades 3 and 4, according to the National Cancer Institute Common Toxicity Criteria [version 2.0]) in the every-3-week treatment arm versus the weekly treatment arm (88.1% vs 55.9%, respectively; P = .0001). CONCLUSIONS. Compared with patients who received weekly docetaxel, those who received docetaxel every 3 weeks had a higher response rate but experienced similar PFS and OS and a more pronounced toxicity.