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

• Drug: enzalutamide
  80 mg (2 capsules) or 160 mg (4 capsules) taken orally daily.
  Other Name: MDV3100, Xtandi
• Drug: anastrozole
  1 mg/day
  Other Name: Arimidex
• Drug: exemestane
  The exemestane dose is 25mg daily.
  Other Name: Aromasin
• Drug: fulvestrant
  500 mg every 28 days
  Other Name: Faslodex
• Drug: enzalutamide
  160 mg (4 capsules) taken orally daily.
  Other Names:

  • MDV3100
  • Xtandi
• Drug: exemestane
  The exemestane dose is 50 mg daily.
  Other Name: Aromasin

• Experimental: enzalutamide (80-mg with increase to 160 mg)
  enzalutamide be provided as two or four 40-mg capsules by mouth daily
  Intervention: Drug: enzalutamide
• Experimental: enzalutamide and anastrozole
  enzalutamide (160 mg) administered as four 40-mg capsules by mouth once daily in combination with anastrozole (1 mg) administered as one 1-mg tablet by mouth once daily.
  Interventions:

  • Drug: anastrozole
  • Drug: enzalutamide
• Experimental: enzalutamide and exemestane 25 mg
  enzalutamide (160 mg) administered as four 40-mg capsules by mouth once daily in combination with exemestane administered as one 25-mg tablet daily
  Interventions:

  • Drug: exemestane
  • Drug: enzalutamide
• Experimental: enzalutamide and exemestane 50 mg
  enzalutamide (160 mg) administered as four 40-mg capsules by mouth once daily in combination with exemestane administered as two 25-mg tablets daily
  Interventions:

  • Drug: enzalutamide
  • Drug: exemestane
• Experimental: enzalutamide and fulvestrant
  enzalutamide (160 mg) administered as four 40-mg capsules by mouth once daily in combination with fulvestrant (500 mg) administered as two 250-mg intramuscular injections every 28 days
  Interventions:

  • Drug: fulvestrant
  • Drug: enzalutamide

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.

• Astellas Pharma Inc
• Medivation LLC, a wholly owned subsidiary of Pfizer Inc.