Lapatinib Combined With Paclitaxel For Patients With First-Line ErbB2-Amplified Metastatic Breast Cancer

Lapatinib will be given as tablets contain 410 mg of lapatinib ditosylate monohydrate, equivalent to 250 mg lapatinib free base per tablet. Subjects will be given a 4 week supply of lapatinib tables and instructed to take 6 tablets daily (1500 mg daily dose) orally at the same time each day. Subjects will receive a daily dose of lapatinib until disease progression or withdrawal from study treatment due to unacceptable toxicity or withdrawal of consent.

Subjects will receive weekly paclitaxel (80 mg/m2 IV for 3 weeks in a 4 week cycle). Subjects will be treated with paclitaxel for at least 6 months, and may continue on paclitaxel at the discretion of the Investigator, or discontinued sooner if the subject has disease progression, an unacceptable toxicity or withdraws consent.