The purpose of this treatment protocol is to provide expanded access to MDV3100 and monitor its safety in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel-based chemotherapy.

THE UNITED STATES FOOD AND DRUG ADMINISTRATION (FDA) AND HEALTH CANADA HAVE APPROVED MDV3100 (ENZALUTAMIDE) FOR SALE TO THE PUBLIC, ENROLLMENT IS CLOSED IN BOTH THE UNITED STATES AND CANADA.

The expanded access treatment protocol is being conducted while marketing approval of enzalutamide is being sought. There is no age requirement.

Subjects will complete visits on Day 1, Week 4, Week 12 and then every subsequent 12 weeks until discontinued from the study.

The study will end if enzalutamide is approved for sale to the public by the country's health authority (commercially available) or if the sponsor otherwise decides or is required to end the study. If a subject would like to receive enzalutamide after the study ends, he and the doctor will decide if he should receive a prescription for enzalutamide, with a goal of avoiding any interruption in treatment.

Inclusion Criteria:

• Histologically or cytologically confirmed adenocarcinoma of the prostate
• Ongoing androgen deprivation therapy with a gonadotropin-releasing hormone (GnRH) analogue (agonist or antagonist) or orchiectomy
• At least one prior chemotherapy regimen for metastatic castration-resistant prostate cancer with at least one regimen containing docetaxel
• Progressive disease as evidenced by prostate specific antigen (PSA) rise or radiographic or clinical worsening of disease
• No known or suspected brain metastasis
• There is no comparable or satisfactory alternative therapy to treat the subject's disease
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2

Exclusion Criteria:

• History of seizure or any condition that may predispose to seizure including, but not limited to underlying brain injury, stroke, primary brain tumors, brain metastases, or alcoholism

• History of loss of consciousness or transient ischemic attack within the last 12 months

• Clinically significant cardiovascular disease

• Following lab values:

  • Absolute neutrophil count is <1,000/µL
  • Platelet count is <50,000/µL
  • Hemoglobin is < 5.6 mmol/L (9 g/dL)
  • Total bilirubin ≥1.5 x upper limit of normal (ULN)
  • Alanine aminotransferase (ALT) or Aspartate aminotransferase (AST) ≥2.5 x ULN
  • Creatinine clearance is less than 30 ml/min by the Cockcroft and Gault formula

• Subject's conditions suggests that a bone fracture or complication of a bone fracture (such as compression of the spinal cord or other nerves) is likely to occur very soon

• Subject has participated in a previous clinical study of MDV3100 for which the primary endpoint has not yet been reported (e.g., the PREVAIL trial)