Oral Drug Study In Women With Refractory Metastatic Breast Cancer After First-line or Second-line Herceptin.

Inclusion Criteria: (The patient must meet the following criteria in order to be eligiblefor this study.)

• Signed informed consent

• No more than two prior regimens for metastatic breast cancer. Each regimen must havecontained Herceptin.

• Refractory Stage IIIb or IV breast cancer

• HER2/neu tumor overexpression

• Disease progression while receiving a prior chemotherapy regimen with Herceptin aloneor in combination with other chemotherapy.

• Tumor tissue available for testing.

• 2 weeks since treatment with Herceptin (alone or in combination).

• Able to swallow and retain oral medication

• Cardiac ejection fraction within the institutional range of normal as measured by MUGA (Multiple Gated Acquisition Scan).

• Adequate kidney and liver function

• Adequate bone marrow function

Exclusion Criteria: (The patient cannot meet any of the following criteria in order to beeligible for this study.)

• Prior regimens did not include Herceptin.

• Pregnant or lactating.

• Conditions that would affect absorption of an oral drug

• Serious medical or psychiatric disorder that would interfere with the patient's safetyor informed consent.

• Severe cardiovascular disease or cardiac disease requiring a device.

• Active infection.

• Brain metastases.

• Concurrent cancer therapy or investigational therapy.

• Use of oral or IV steroids.

• Unresolved or unstable serious toxicity from prior therapy.

• Treatment with EGFR (Endothelial Growth Factor Receptor) inhibitor other thanHerceptin.