Inclusion Criteria:

- Women with diagnosis of primary adenocarcinoma of the breast

- Presence of locally advanced or metastatic disease non-amenable to surgery or
radiation therapy with curative intent

- At least one measurable lesion >20mm (or >10 mm with spiral CT scan)

- Must have received (and failed) prior treatment with an anthracycline, a taxane, and
capecitabine in the adjuvant and/or advanced disease treatment setting

- Women at least 18 years old, with performance status 0-2

Exclusion Criteria:

- Prior treatment with another topoisomerase I inhibitor

- Current enrollment in another clinical trial