Inclusion Criteria:

- Signed informed consent

- Women >=18 years of age

- Histologically documented, incurable, locally advanced or metastatic breast cancer

- Disease progression on or after therapy with an anthracycline, a taxane, and
capecitabine (Cohort 1), or disease progression on or after therapy with at least one
chemotherapy regimen for locally advanced or metastatic disease (Cohort 2)

- Measurable disease of >=2 cm (>=1 cm on spiral CT scan). Disease at previously
irradiated sites is considered measurable if there is clear disease progression
following radiation therapy.

- HER2 negative, HER2 unknown, or HER2 positive and disease progression following
Herceptin(R) (trastuzumab) therapy

- ECOG performance status of 0 to 2

- Life expectancy of >=3 months

- Use of effective means of contraception in women of childbearing potential

- Ability to comply with study and follow-up procedures

Exclusion Criteria:

- Pleural effusions or blastic bone lesions as the only manifestations of the current
metastatic breast cancer

- Other primary malignancies within 5 years except for adequately treated carcinoma in
situ of the cervix or basal or squamous cell skin cancer

- Symptomatic or untreated brain metastases

- Radiotherapy, immunotherapy, hormonal therapy, or chemotherapy within 21 days prior
to Day 0 (6 weeks for nitrosoureas or mitomycin); prior therapy with an agent
designed to target either the EGFR or EGFR-specific tyrosine kinase activity

- INR >4.0 for patients receiving warfarin

- Cumulative anthracycline and anthracenedione exposure as follows: doxorubicin >450
mg/m, liposomal doxorubicin >550 mg/m, epirubicin >700 mg/m, or mitoxantrone >140
mg/m

- Cardiac ejection fraction (MUGA or echocardiogram) less than the local institution
lower limit of normal

- Unstable systemic disease, including active infection, uncontrolled hypertension,
unstable angina, congestive heart failure, or myocardial infarction within 6 months
prior to Day 0, or serious cardiac arrhythmia requiring medication

- Major surgery, biopsy of a parenchymal organ, or significant traumatic injury
occurring within 21 days prior to Day 0

- History of other diseases, metabolic dysfunction, physical examination finding, or
clinical laboratory finding giving reasonable suspicion of a disease or condition
that contraindicates the use of an investigational drug or that might affect the
interpretation of the results of the study or render the patient at high risk from
treatment complications

- Abnormalities of the cornea based on history (e.g., dry eye syndrome, Sjogren's
syndrome), congenital abnormality (e.g., Fuch's dystrophy), abnormal slit-lamp
examination using a vital dye (e.g., fluorescein, Bengal-Rose), and/or an abnormal
corneal sensitivity test (Schirmer test or similar tear production test)

- Gastrointestinal tract disease resulting in an inability to take oral medication or a
requirement for IV alimentation, prior surgical procedures affecting absorption, or
active peptic ulcer disease

- Pregnancy or lactation

- Any of the following abnormal baseline hematologic values: *Granulocyte count
<=1500/uL; *Platelet count <100,000/uL; *Hemoglobin <9 gm/dL (transfusion permitted)

- Any of the following abnormal baseline liver function tests: *Serum bilirubin >=1.5x
upper limit of normal (ULN); *Serum ALT and AST >=2.5x ULN (>5x ULN if due to liver
metastases); *Alkaline phosphatase >=2.5x ULN (>4x ULN if due to liver or bone
metastases)

- Other baseline laboratory values: *Serum creatinine >=1.5x ULN or creatinine
clearance <=60 mL/min; *Uncontrolled hypercalcemia (>11.5 mg/dL); *Serum albumin
<=3.0 g/dL