Final Results of a Phase II Clinical Trial of Weekly Docetaxel in Combination with Capecitabine in Anthracycline-Pretreated Metastatic Breast Cancer

Abstract

The addition of capecitabine to docetaxel on a 3-week schedule resulted in superior response rate, increased time to progression (TTP), and improved overall survival in patients with anthracycline-pretreated metastatic breast cancer (MBC). Because the toxicity profile of weekly docetaxel differs from the standard 21-day docetaxel schedule, we performed a phase I/II trial to test the efficacy and safety of weekly docetaxel in combination with capecitabine given for 14 days every 21 days. The phase I study identified the doses of docetaxel (30 mg/m 2 weekly) and capecitabine (900 mg/m 2 twice daily on days 1-14 every 21 days) used in phase II. Twenty female patients with measurable or assessable MBC were enrolled. Eighteen patients had previously received anthracyclines; 2 had contraindications to anthracyclines. Patients remained on study for a maximum of eight 3-week cycles or until tumor progression or unacceptable toxicity occurred; response assessments were scheduled after cycle 2, 5, and 8. Seventeen patients were assessed after cycle 2; 3 subjects (18%) had a partial response (PR), 9 had stable disease (53%; SD), and 5 patients (29%) had progressive disease (PD). Ten patients were assessable after cycle 5. Two patients (20%) had a PR, 5 patients (50%) had SD, and 3 patients (30%) had PD. The most common grade 3 toxicities were nail loss (45%), asthenia (30%), and hand-foot syndrome (30%), and toxicities led to study discontinuation in 10 patients. The median time to treatment failure was 10 weeks and median TTP was 26 weeks. The median duration of response was 9 weeks and the median duration of SD was 16 weeks. The median overall survival was 82 weeks. This schedule of weekly docetaxel in combination with day 1-14 capecitabine has activity; however, toxicity discourages the use of this schedule in lieu of the standard docetaxel/capecitabine regimen.