Results of a phase I trial of intravenous vinorelbine plus oral capecitabine as first-line chemotherapy of metastatic breast cancer.

The management of metastatic breast cancer becomes increasingly intricate, requiring new drugs and combinations. We present here the results of a phase I study evaluating the maximal tolerated dose of vinorelbine combined with capecitabine as first-line chemotherapy. Vinorelbine was administered intravenously on days 1 and 15, and capecitabine was given orally twice daily from day 1 to 14 (three cycles every 21 days). Three out of six patients receiving vinorelbine at 25mg/m2/day and capecitabine at 2000 mg/m2/day presented with a dose-limiting toxicity, consisting of protracted grade 3 neutropenia, hand-foot syndrome and/or liver test disturbances. Despite of a dose reduction in vinorelbine (20mg/m2/day), one patient among four developed a dose-limiting febrile neutropenia. This regimen cannot be recommended as first-line treatment of metastatic breast cancer. These findings are not in agreement with previous publications of this schedule, or with promising results using both drugs orally.