Patients must with Her2+(ErbB2+) MBC Stage IV, newly diagnosed will receive paclitaxel+lapatinib or paclitaxel plus placebo for 6 cycles minimum. After 6 cycles continue to receive blinded monotherapy until progression. Safety evaluations include evaluating adverse events, hematology/ chemistry tests, vital signs, and cardiac muga scans. Efficacy assessments include evaluation of disease per RECIST. All patients followed for overall survival (OS).