This is a Phase I/II study to evaluate the safety profile, tolerability, pharmacokinetics and pharmacodynamics following daily oral doses of 50 to 200 mg of BMS-754807 in combination with trastuzumab (Herceptin®) in subjects with advanced or metastatic Her-2-positive breast cancer. In addition, the study is expected to identify the recommended dose or dose range of BMS-754807 in combination with trastuzumab for Phase II studies and provide preliminary evidence of anti-tumor activity in Her-2-positive breast cancer subjects after trastuzumab failure