Background: After two studies reporting response rates higher than 70% in HER2-positive metastatic breast cancer with weekly trastuzumab and vinorelbine, we planned a phase 2 study to test activity of the same combination, with trastuzumab given every 3 weeks.
Methods: Patients with HER2-positive metastatic breast cancer (3+ at immunohistochemistry or positive at fluorescence in situ hybridization), PS < or =2, normal left-ventricular ejection fraction (LVEF) and no more than one chemotherapy line for metastatic disease were eligible. Vinorelbine (30 mg/m2) was given on days 1 & 8 every 21 and trastuzumab (8 mg/kg day 1, then 6 mg/kg) every 21 days).