Inclusion Criteria:

- Patients must have histologically or cytologically confirmed invasive breast cancer;
patients without pathologic or cytologic evidence of metastatic disease should have
unequivocal evidence of metastasis on radiographic study or physical exam; patients
must have metastatic (stage IV) breast cancer, or locally advanced (stage IIIB)
breast cancer that cannot be treated with curative intent

- Patients must have measurable disease, defined as lesions that can be accurately
measured in at least one dimension (longest diameter to be recorded) as >= 10 mm with
conventional techniques; lytic bone lesions meeting these criteria will be considered
measurable disease

- Patients are required to have had at least one prior chemotherapy regimen for
advanced breast cancer unless they have progressed within 12 months of concluding
adjuvant chemotherapy; patients may not have had more than 2 prior chemotherapy
regimens for advanced breast cancer; treatment with high-dose chemotherapy and stem
cell support in the metastatic setting, including induction chemotherapy, will be
considered 2 treatment regimens; patients may have received adjuvant chemotherapy;
patients who have metastatic breast cancer diagnosed within 12 months of concluding
adjuvant chemotherapy will be eligible after 0 or 1 regimens in the metastatic
setting; patients may have received prior hormonal therapy of any type; patients may
have been previously treated with investigational agents or biological agents (e.g.
Herceptin)

- Patients must have concluded prior therapy no less than the duration of one cycle of
treatment prior to beginning treatment with rebeccamycin analog, but in all cases
there must be at least a 2 week interval since last treatment; thus, if a patient is
receiving therapy every three weeks, the patient must be at least three weeks from
the last treatment before beginning protocol-based therapy; patients must have
recovered from the toxicities of prior therapy, and meet the performance status and
laboratory criteria for eligibility before beginning treatment

- Patients may not receive concurrent anti-neoplastic therapy; all other radiation
therapy, hormonal therapy, or treatment with trastuzumab (Herceptin) must be stopped
prior to treatment on protocol; patients receiving bisphosphonate therapy may
continue to receive these treatments while on protocol

- Life expectancy of greater than 3 months

- ECOG performance status =< 1 (Karnofsky >= 70%)

- Absolute neutrophil count (ANC) >= 1,500/uL

- Platelets >= 100,000/uL

- Total bilirubin within normal institutional limits

- AST(SGOT)/ALT(SGPT) =< 2.5 x institutional upper limit of normal

- Creatinine =< 2 mg/dl

- Sodium (Na) within normal institutional limits

- Serum lipase within normal institutional limits

- Serum amylase within normal institutional limits

- Because rebeccamycin analog has been associated with phlebitis, all therapy on
protocol will be given through a central venous line; patients not willing to have a
central line, or those in whom central venous access could not be established, will
not be eligible

- The effects of rebeccamycin analog on the developing human fetus at the recommended
therapeutic dose are unknown; for this reason, women of child-bearing potential must
agree to use adequate contraception prior to study entry and for the duration of
study participation; women should not become pregnant or nurse, nor expect to become
pregnant or nurse, during the study; women in whom there is a suspicion of possible
pregnancy must have a documented negative serum pregnancy test prior to beginning
therapy; should a woman become pregnant or suspect she is pregnant while
participating in this study, she should inform her treating physician immediately

- Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

- Patients with only non-measurable disease, defined as all other lesions, including
small lesions (longest diameter < 10 mm with conventional techniques) and truly
non-measurable lesions, which include the following:

- Bone lesions, except pure lytic lesions

- Leptomeningeal disease

- Tumor markers

- Ascites

- Pleural/pericardial effusions

- Patients who have had radiotherapy within 2 weeks prior to entering the study or
those who have not recovered from adverse events due to prior chemotherapy
administered previously

- Patients may not be receiving any other investigational anti-neoplastic agents, with
the following exceptions: patients may participate in concurrent studies of
supportive therapies, including anti-nausea or bisphosphonate-based treatments

- Patients with known brain metastases may be included if they meet the following 2
criteria:

- Completed whole brain irradiation at least two months prior to study entry

- Have no symptoms from brain metastases

- Lack of central venous access

- Uncontrolled intercurrent illness including, but not limited to ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
study requirements

- Pregnant women are excluded from this study; breastfeeding should be discontinued if
the mother is treated on study

- HIV-positive patients receiving combination anti-retroviral therapy are excluded from
the study