- Surgically sterile or post-menopausal women.
- Confirmed pathologic diagnosis of breast cancer.
- Locally advanced or metastatic, or loco-regional recurrent breast cancer not amenable
to curative treatment with surgery or radiotherapy.
- Documented ER+ and/or PgR+ and erbB2- tumor based on most recently analyzed biopsy, as
documented by a local laboratory.
- At least 1 radiologically measurable lesion as defined by Response Evaluation Criteria
in Solid Tumors (RECIST).
- Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
- Prior letrozole (except in adjuvant setting), prior bosutinib, or any other prior Src
- Prior endocrine treatment for locally advanced or metastatic breast cancer (up to one
prior adjuvant Aromatase Inhibitor (AI) agent/regimen is permitted).
- More than 1 prior chemotherapy regimen in locally advanced or metastatic breast
- Adjuvant endocrine therapy
- Disease refractory (ie, Progressive disease (PD) within 6 months from initiation of
therapy) to previous adjuvant antiestrogen therapy.
- Bone or skin as the only site of disease.
- Extensive visceral disease or active Central Nervous System (CNS) disease.
- Any other cancer within 5 years of screening with the exception of ER+ contralateral
breast carcinoma, adequately treated cervical carcinoma in situ, or adequately treated
basal or squamous cell carcinoma of the skin.
- Major surgery or radiotherapy within 14 days of treatment day.
- Inadequate hepatic/renal/bone marrow function.
- History of clinically significant or uncontrolled cardiac disease.
- Serious concurrent illness.