Trastuzumab plus vinorelbine or taxane chemotherapy for HER2-overexpressing metastatic breast cancer: the trastuzumab and vinorelbine or taxane study.

BACKGROUND: The optimal trastuzumab-based chemotherapy regimen for HER2-overexpressing, metastatic breast cancer is not known. The trastuzumab and vinorelbine or taxane (TRAVIOTA) study was a prospective, multicenter, randomized trial that was designed to compare these regimens.

METHODS: Eligible patients had HER2-overexpressing, metastatic breast cancer and had received no prior chemotherapy for advanced disease. Patients were randomized 1:1 to receive either trastuzumab with weekly vinorelbine therapy or weekly taxane therapy (paclitaxel or docetaxel at the investigator's choice). Originally planned for 250 patients, the study was closed because of poor accrual with 81 evaluable patients, including 41 patients who received vinorelbine and 40 patients who received taxane.

RESULTS: Response rates were 51% and 40% for the vinorelbine/trastuzumab arm and the taxane/trastuzumab arm, respectively (Fisher exact test; P = .37). The median time to disease progression was 8.5 months and 6.0 months for the vinorelbine- and taxane-based arms, respectively (log-rank test; P = .09). Treatment with either regimen generally was well tolerated, yielding comparable rates of neurologic and gastrointestinal toxicity. Vinorelbine-based treatment was associated with more anemia and neutropenia and with 2 episodes of cardiotoxicity. Taxane-based therapy was associated with more dermatologic toxicity, myalgias, and fluid retention.

CONCLUSIONS: Both vinorelbine/trastuzumab and taxane/trastuzumab treatments were active as first-line therapy for HER2-positive, metastatic breast cancer and had comparable rates of efficacy and tolerability. The toxicities observed were the result of recognized side effects associated with each of the chemotherapy agents and schedules. These data can inform treatment decision making in this clinical setting.