The purpose of this study is to collect additional safety information on abiraterone acetate administered with prednisone to patients with metastatic castration-resistant prostate cancer (CRPC).

This is a study to collect information on adverse events (side effects) that occur during treatment with abiraterone acetate in patients with metastatic castration-resistant prostate cancer (CRPC). To participate in this study patients must have failed 1 or 2 chemotherapy regimens (1 of which contained a taxane such as docetaxel), reside in an area where abiraterone acetate is not yet available through local healthcare providers, and not be eligible for enrollment in any other ongoing clinical research study of abiraterone acetate. CRPC is progressive form of prostate cancer where the cancer cells become resistant to hormonal therapies that are designed to block the release or uptake of testosterone and the cancer cells metastasize (ie, spread to other parts of the body). Abiraterone acetate (referred to as abiraterone) is a drug currently under development for use in treating men with CRPC. Patients will be treated with abiraterone and prednisone daily until progression of clinical disease (ie, includes signs of clinical disease progression and/or clinical disease progression confirmed by radiographic and prostate-specific antigen [PSA] test results). Other reasons for discontinuation of treatment may include adverse events reported, initiation of other anticancer therapies, or the patient's inability to comply with dosing instructions. Patients will be followed for 30 days after the discontinuation of treatment with abiraterone acetate. Patients will take four 250-mg tablets of abiraterone orally at least 1 hour before a meal or 2 hours after a meal any time up to 10 pm every day. Patients will also take 5 mg of oral prednisone, twice daily. Each treatment cycle consists of 28 days and patients will take abiraterone continually on a daily basis until disease progression is observed at which time abiraterone will be discontinued and the dose of prednisone reduced if clinically indicated.

Inclusion Criteria:

• Confirmed prostate cancer
• Prostate cancer progression after previous chemotherapy as assessed by the investigator
• Received at least 1 but not more than 2 chemotherapy regimens for metastatic CRPC (at least one regimen must have contained a taxane such as docetaxel)
• Serum testosterone of less than 50ng/dL (less than 2.0 nM)
• Eastern Cooperative Oncology Group (ECOG) performance status of <=2 (ie, patients who do not have symptoms of prostate cancer and who are fully active, patients who have symptoms but are able to perform light work, or patients who are able to get around and are capable of taking care of themselves but are unable to carry out any work activities)

Exclusion Criteria:

• Serious or uncontrolled co-existent non-malignant disease (including active and uncontrolled infection)
• Active or symptomatic viral hepatitis or chronic liver disease or any abnormal liver function assessed by liver function tests
• Clinically significant heart disease as assessed by the Investigator or uncontrolled hypertension (systolic blood pressure >=160 mmHg or diastolic blood pressure >=95 mmHg)
• History of gastrointestinal disorders that may interfere with the absorption of the study drug or history of pituitary or adrenal dysfunction
• Known brain metastasis (ie, spread of cancer to the brain)