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Inclusion Criteria:

- Females with confirmed breast cancer

- Age ≥ 18 years

- Eastern Cooperative Oncology Group (ECOG) Performance Status 0 to 2

- Locally advanced or metastatic disease who have received at least two prior
chemotherapeutic regimens for breast cancer, as follows:

- At least one regimen must have been for locally advanced or metastatic disease

- Subject must have received an anthracycline, a taxane, and capecitabine in any
combination unless the subject was intolerant to or not a candidate for any of
these agents

- Hormonal therapy, biologic therapy (such as trastuzumab or bevacizumab), or
immunotherapy do not count as one of the 2 regimens

- Subjects with HER2/neu overexpressing tumors must have been treated with
trastuzumab except in situations where the subject was intolerant to or not a
candidate for trastuzumab

- Documented progressive disease within 6 months of the last regimen

- Adequate bone marrow, renal and liver function

- Signed informed consent

Main Exclusion Criteria:

- Chemotherapy, radiation, hormonal therapy, or bevacizumab within two weeks, or
trastuzumab or investigational therapy within three weeks before treatment start

- Neuropathy > NCI-CTCAE Grade 1

- Active brain metastases.

- New York Heart Association class III or IV heart disease

- Unstable angina

- Uncontrolled arrhythmia

- A marked baseline prolongation of QT/QTc interval

- Pregnant or breast-feeding women, and women of childbearing age and potential who are
not willing to use effective contraception