Safety Study of Enzalutamide (MDV3100) in Patients With Incurable Breast Cancer

Inclusion Criteria:

- Histologically confirmed breast cancer with accompanying pathology report;

- Submit unstained representative tumor specimen, either as a paraffin block (preferred)
or ≥ 10 unstained slides

- Received at least 2 lines of systemic therapy in the advanced setting (for
enzalutamide alone arm only);

- Eastern Cooperative Oncology Group performance (ECOG) status of 0 or 1;

- Estimated life expectancy of at least 3 months

Exclusion Criteria:

- Severe concurrent disease, infection, or comorbidity that, in the judgment of the
Investigator, would make the patient inappropriate for enrollment;

- Pregnant or lactating;

- Known or suspected brain metastasis or leptomeningeal disease;

- History of another malignancy within the previous 5 years other than curatively
treated in situ carcinomas;

- For patients who are enrolled to receive enzalutamide plus anastrozole or exemestane
or fulvestrant must not have received tamoxifen or any medication known to be a potent
CYP3A4 inducer or inhibitor.