Inclusion Criteria:

- Females or males with histologic confirmation of breast carcinoma and diagnosis of
metastatic breast adenocarcinoma

- Confirmed HER2 amplification by immunohistochemical staining (IHC) 3+ or FISH
amplified (either primary or metastatic).

- Have had any number of prior HER2 targeted therapy containing chemotherapies for
treatment of breast cancer

- Measurable extent of disease

- Life expectancy of 3 months or greater

- Patients must have adequate heart function, determined with ECHO or MUGA (ECHO
preferred).

- Patients must have adequate bone marrow and organ function

- Patient of childbearing potential must be willing to use an effective means of
contraception during their participation on trial

- Greater than 3 weeks from prior radiation or chemotherapy; more than 1 week from
prior hormonal therapy; and more than 6 weeks from prior treatment with nitrosoureas
or mitomycin.

- No serious intercurrent medical illness.

- Controlled metastatic CNS disease ≥ 3 months

- The ability to understand and willingness to sign a written informed consent form,
and to comply with the protocol.

Exclusion Criteria:

- Pregnant or nursing women

- Patients who are poor medical risk because of other non-malignant systemic disease or
active, uncontrolled infection.

- Prior craniospinal radiation, or total body irradiation (TBI).

- Patients receiving G-CSF (filgrastim or pegfilgrastim) or thrombopoietin (or other
platelet growth factors) within the 3 weeks prior to enrollment (erythropoietin is
allowed).

- Prior chemotherapy within the last 3 weeks (last 6 weeks for nitrosureas/mitomycin).

- Prior radiation therapy within the last 3 weeks; prior radiation therapy to indicator
lesion (unless objective disease recurrence or progression within the radiation
portal has been documented since completion of radiation).

- Concomitant malignancies or previous malignancies within the last 5 years, with the
exception of adequately treated basal or squamous cell carcinoma of the skin or
carcinoma in situ of the cervix.

- Current symptoms of angina or uncontrolled arrhythmias, uncontrolled hypertension
with systolic blood pressure >=170 or diastolic blood pressure >=110.

- Psychiatric illness precluding participation in study

- Symptomatic intrinsic lung disease or extensive tumor involvement of the lungs,
resulting in dyspnea at rest.

- Carcinomatous meningitis or CNS mets not controlled for ≥ 3 months.