Purpose: To determine the dose-limiting toxicities (DLTs) and the maximum tolerated doses (MTD) of oral metronomic vinorelbine with capecitabine in patients with metastatic breast cancer (MBC).
Patients and methods: Escalated doses of oral metronomic vinorelbine (starting dose 30 mg) every other day continuously and capecitabine (starting dose 800 mg/m(2) bid) on days 1-14 every 21 days were administered. DLTs were evaluated during the first cycle.
Results: Thirty-six women were enrolled at eight escalating dose levels. For twenty-four patients, treatment was first line, for eight second line, and for four third line. The DLT level was reached at oral metronomic vinorelbine 70 mg and capecitabine 1,250 mg/m(2), and the recommended MTD doses are vinorelbine 60 mg and capecitabine 1,250 mg/m(2). DLTs were febrile neutropenia grade 3 and 4, diarrhea grade 4, and treatment delays due to unresolved neutropenia. There was no treatment-related death. The main toxicities were grade 2-3 neutropenia in 16.6% of patients each, grade 2-3 anemia 16.5%, grade 2-4 fatigue 27.5%, grade 2-3 nausea/vomiting 11%, and grade 3-4 diarrhea 8.2%. Two complete and 10 partial responses were documented.
Conclusion: Oral metronomic vinorelbine with capecitabine is a well-tolerated and feasible regimen that merits further evaluation in MBC.