Inclusion Criteria:

- Histologically or cytologically confirmed, HER2-negative adenocarcinoma of the
breast, with measurable or non-measurable locally recurrent or metastatic disease.
Locally recurrent disease must not be amenable to resection with curative intent.

- ECOG performance status of 0 or 1

- For women of childbearing potential, use of an acceptable and effective method of
non-hormonal contraception

- For patients who have received recent radiotherapy, recovery prior to randomization
from any significant acute toxicity, and radiation treatments have to be completed
more than 3 weeks from randomization

Exclusion Criteria:

Disease-Specific Exclusions:

- HER2-positive status

- Prior chemotherapy for locally recurrent or metastatic disease

- Prior hormonal therapy < 2 weeks prior to randomization

- Prior adjuvant or neo-adjuvant chemotherapy is allowed, provided its conclusion has
been for at least 12 months prior to randomization

- Investigational therapy within 28 days of randomization

General Medical Exclusions:

- Life expectancy of < 12 weeks

- Inadequate organ function

- Uncontrolled serious medical or psychiatric illness

- Active infection requiring intravenous (IV) antibiotics at screening

- Pregnancy or lactation

- History of other malignancies within 5 years prior to screening, except for tumors
with a negligible risk for metastasis or death