Efficacy of oral vinorelbine (NVBo), capecitabine (X) and trastuzumab (H) triple combination (NVBoXH) in HER2-positive metastatic breast cancer (MBC): First results of an international phase II trial

1052 Background: Chemotherapy (CT) plus H is the standard first-line treatment for HER2-positive MBC. H plus vinorelbine is an active and well-tolerated regimen in this setting. The all-oral combination of NVBo and X also appears active and well-tolerated in MBC. We report efficacy and safety results from the first 34 patients (pts) included in an international trial evaluating NVBoXH in HER2-positive MBC. Methods: In this multicenter trial, main eligibility criteria included: HER2-positive disease (IHC 3+ or FISH+), documented measurable MBC previously untreated by CT, relapse 6 months after completing neoadjuvant or adjuvant CT, Karnofsky PS = 70, age =18 years. Pts received 3-weekly cycles of NVBo 60 mg/m2 (cycle 1) escalating to 80 mg/m2 (from cycle 2) days 1 and 8; × 1,000 mg/m2 bid (750 if = 65 years) days 1–14; H 4 mg/kg day 1 as a loading dose then 2 mg/kg i.v. weekly starting on day 8. Treatment was continued until progression or unacceptable toxicity. Primary endpoint is overall response rate. R...