Efficacy and Tolerability of Eribulin Plus Lapatinib in Patients With Metastatic Breast Cancer (E-VITA)

Primary Objectives 1. To assess the time to progression (TTP) of eribulin at a dose of 1.23 mg/m² IV days 1+8, q 21 and eribulin given at a dose of 1.76 mg/m² IV day 1, q d21 both in combination with lapatinib. 2. To assess the safety and toxicity of both treatment arms. Secondary Objectives 1. To determine the objective response rate of both treatment arms. 2. To determine the overall clinical benefit rate (CR + PR + SD \>24 weeks) of both treatment arms. 3. To determine overall survival in both treatment arms 3 years after 1st patient has been randomized. 4. To assess biomarkers like PI3K mutation, PTEN expression, c-myc on the primary tumor and correlate them with TTP in both treatment arms.