Phase 2 Trial of a Novel Capecitabine Dosing Schedule in Combination With Bevacizumab for Patients With Metastatic Breast Cancer

BACKGROUND: Capecitabine has antitumor activity in metastatic breast cancer (MBC); however, its optimal dose and schedule remain unclear. Mathematical modeling predicts that a capecitabine schedule 7 days of treatment followed by 7 days of rest (7-7) will improve efficacy and minimize toxicity. Bevacizumab has demonstrated the ability to improve outcomes when it is added to chemotherapy, including capecitabine, in the first-line and second-line settings. METHODS: Patients with measurable MBC received oral capecitabine (2000 mg twice daily; 7-7), and intravenous bevacizumab (10 mg/kg every 2 weeks). The primary endpoint was the response rate. Secondary endpoints included toxicity, the clinical benefit rate, and progression-free survival (PFS). RESULTS: Forty-one patients were treated. After a median of 7 cycles (range, 1-32 cycles), partial responses were observed in 20% of patients, and stable disease for >= 6 months was noted in 35% patients. The median PFS was 8 months. The most common treatment-related toxicities were hand-foot syndrome (49% grade 2, 20% grade 3/4) hypertension (12% grade 2, 10% grade 3/4), and fatigue (12% grade 2, 2% grade 3/4). Diarrhea (5% grade 2, 0% grade 3/4), nausea (0% grade 2-4), and vomiting (0% grade 2-4) were rare. CONCLUSIONS: Capecitabine administered for 7 days followed by a 7-day rest in combination with bevacizumab had modest efficacy and an acceptable toxicity profile in patients with MBC. Gastrointestinal toxicity with this schedule was minimal. Cancer 2011;117:4125-31. (C) 2011 American Cancer Society.