Oral Deforolimus With Trastuzumab for Patients With HER2-positive Trastuzumab-Refractory Metastatic Breast Cancer (8669-009)

Inclusion Criteria: * Female, 18 years of age or older * Histologically confirmed HER2-positive metastatic breast cancer * Trastuzumab-resistance * Measurable disease, according to RECIST guidelines * ECOG performance status less than or equal to 1 * Life expectancy greater than 3 months * No prior treatment with temsirolimus, everolimus, rapamycin, or any other mTOR inhibitor * At least 4 weeks must have lapsed between prior investigational therapy, chemotherapy or radiotherapy, and the first dose of ridaforolimus * Left ventricular ejection greater than or equal to 50% * Adequate cardiovascular function * Adequate hematological, hepatic, and renal function * Serum cholesterol less than or equal to 350 mg/dL and triglycerides less than or equal to 400 mg/dL * Negative pregnancy test within 7 days prior to first dose of study drug and must use an approved contraceptive method from screening to 30 days after the last dose of study drug * Availability and patient consent to obtain archival tissue samples * Signed informed consent Exclusion Criteria: * Inadequate recovery from any prior surgical procedure or having undergone any major surgery within 2 weeks before trial entry * Grade 1 or Grade 2 hypersensitivity reactions to prior trastuzumab therapy if these reactions prevented further trastuzumab administration * Grade 3 or Grade 4 hypersensitivity reaction to prior trastuzumab * Symptomatic intrinsic lung disease or extensive tumor involvement of the lungs, resulting in dyspnea at rest * Known allergy to macrolide antibiotics * Pregnant or breast-feeding * Know history of HIV * Diagnosis of brain metastasis or leptomeningeal carcinomatosis within 3 months * Other malignancies within the past 3 years, except for adequately treated carcinoma of the cervix or basal or squamous cell carcinoma of the skin * Active infection requiring prescription intervention * Newly diagnosed or poorly controlled Type 1 or 2 diabetes * Other concurrent illness which, in the Investigator's judgment, would either compromise the patient's safety or interfere with the evaluation of the safety of the study drug * Concurrent treatment with medications that strongly induce or inhibit cytochrome P450. * Any condition that renders patient unable to fully understand and provide informed consent and/or comply with the protocol