The purpose of this clinical trial is to determine if the investigational drug is able to reduce/shrink advanced breast cancer tumors in patients who no longer benefit from anthracyclines, taxanes and capecitabine.

All patients in this trial will receive the investigational (chemotherapy) drug at an optimal dose as determined by previous clinical trials. The investigational drug is given through a vein once every three weeks. This drug prevents tumor cells from dividing, so they may stop growing or die.

Inclusion Criteria:

In order to be eligible for this trial you must:

• Have a diagnosis of breast cancer that is now metastatic (meaning the cancer has spread beyond its original location) or a recurrence of the cancer in its original location that cannot be removed by surgery.
• Have received previous treatment with anthracyclines (e.g. doxorubicin [Adriamycin or Doxil] or epirubicin [Ellence]), taxanes (paclitaxel [Taxol or Abraxane] or docetaxel [Taxotere]) and capecitabine (e.g. Xeloda) for your breast cancer and your doctor has determined that these treatments are no longer of benefit to you.
• Be at least 18 years of age
• Not be taking other treatments for your cancer at the time you enter the trial.
• Not be pregnant
• Additionally, there are other criteria for study entry that a doctor participating in this study will need to review in detail with you and clinical assessments may need to be performed (lab tests, CT scans).

Exclusion Criteria:

• None listed here. Can be discussed with your doctor.