Inclusion Criteria:

- Signed informed consent;

- Female ≥18 years;

- Pathology that has histologically confirmed invasive breast cancer with stage IIIb/c
or stage IV disease;

• If recurrent disease is restricted to a solitary lesion, its neoplastic nature
should be confirmed by cytology or histology.

- Documented overexpression of Her2(ErbB2) of IHC 3+ or FISH positive, in primary or
metastatic tumor tissue is required for enrollment into the study; by local testing
or central laboratory testing determined by country of residence. NB. Approximately,
51 subjects will be enrolled in a single stage design to test for efficacy in women
from China and Hong Kong. Due to the fact that trastuzumab is not commonly prescribed
in China and Hong Kong, the current study allows up to 40% of subjects who are
trastuzumab naïve to be enrolled.

- Prior therapies must include at minimum a taxane and/or anthracycline and may include
trastuzumab if available; other prior regimens are not limited except capecitabine
and ErbB1/Erbb2 inhibitors other than trastuzumab. Chemo regimen requirements are as
follows:

- Taxane containing regimen for at least 4 cycles or <4 cycles provided disease
progression or treatment limiting toxicity occurred while on taxane

- Anthracycline containing regimen for at least 4 cycles or <4 cycles provided
disease progression or treatment limiting toxicity occurred while on
anthracycline

- Taxanes and Anthracyclines may have been administered concurrently or separately

- Prior treatment may have contained trastuzumab alone or in combination with
other chemotherapy in the adjuvant, locally advanced or metastatic setting and
patient must have failed the treatment

- Prior treatment with capecitabine is not permitted unless 6 months have elapsed
since the last dose of capecitabine and the subject is free of any capecitabine
related toxicity

- Prior therapy with an ErbB1 and/or ErbB2 inhibitor, other than trastuzumab is
not permitted

- Other prior chemo-regimens not listed above are unlimited.

- For those subjects whose disease is ER+ and/or PR+ one of following criteria should
be met.

- Subjects who received hormonal therapy and are no longer benefiting from this
therapy and the hormonal treatment must have been stopped before the first dose
of investigational treatment

- Subjects with visceral disease that requires chemotherapy (eg., subjects with
liver or lung metastases)

- Rapidly progressing or life threatening disease, as determined by the
investigator

- Subjects with stable CNS metastases (asymptomatic and off systemic steroids and
anticonvulsants for at least 3 months) are eligible

- Measurable lesion(s) according to RECIST (Response Evaluation Criteria in Solid
Tumors);

- Radiotherapy as palliative treatment for painful metastatic disease is permitted but
must have been stopped within 2 weeks prior to initiation of any investigational
treatment. All subjects must have recovered from all radiotherapy related toxicities
prior to initiation of any investigational treatment. The site of radiotherapy must
not be used as a site of measurable disease;

- Cardiac ejection fraction within institutional range of normal as measured by
echocardiogram. MUGA scans will be accepted in cases where an echocardiogram cannot
be performed or is inconclusive;

- ECOG Performance Status of 0 to 1;

- Life expectancy of ≥ 12 weeks;

- Able to swallow and retain oral medication;

- Women with potential to have children must be willing to practice acceptable methods
of birth control during the study;

- Willing to complete all screening assessments as outlined in the protocol;

- Adequate organ function as defined by the Table of Baseline Laboratory Values

Exclusion Criteria:

- Pregnant or lactating females at anytime during the study

- Subjects with only non-measurable metastatic sites of disease per RECIST, (e.g. bone
metastases, pleural effusion, or ascites, etc.;

- Planned concurrent anti-cancer therapy (chemotherapy, radiation therapy,
immunotherapy, biologic therapy, hormonal therapy) while taking investigational
treatment;

- Unresolved or unstable, serious toxicity from prior administration of another
investigational drug and/or of prior cancer treatment;

- Malabsorption syndrome, disease significantly affecting gastrointestinal function, or
resection of the stomach or small bowel. Subjects with ulcerative colitis are also
excluded;

- History of other malignancy. However, subjects who have been disease-free for 5
years, or subjects with a history of completely resected non-melanoma skin cancer or
successfully treated in situ carcinoma, are eligible;

- Concurrent disease or condition that would make the subject inappropriate for study
participation, or any serious medical disorder that would interfere with the
subject's safety;

- Uncontrolled infection;

- Dementia, altered mental status, or any psychiatric condition that would prohibit the
understanding or rendering of informed consent;