Inclusion Criteria:

- Completed 12 cycles of abiraterone acetate under study COU-AA-001

- Last dose of abiraterone acetate within 14 days prior to treatment in this study

- Demonstrates potential to gain clinical benefit with continued abiraterone acetate
treatment

- Serum potassium level >=3.5 mmol/L

- Eastern Cooperative Oncology Group Performance Status of <3 (Karnofsky Performance
Status >=30%)

- Agrees to protocol-defined use of effective contraception

Exclusion Criteria:

- Serious or uncontrolled co-existent non-malignant disease, including active and
uncontrolled infection

- Uncontrolled hypertension

- Abnormal liver function

- Clinically significant heart disease as evidenced by a myocardial infarction in the
past 12 months, severe or unstable angina, or New York Heart Association (NYHA) Class
III or IV heart disease (patients with a history of atherosclerotic vascular disease
requiring coronary or peripheral artery bypass surgery may be enrolled provided the
surgery occurred at least 2 years prior to enrollment and after consultation with a
cardiologist to insure that the disease is stable)

- Condition or situation which, in the investigator's opinion, may put the patient at
significant risk, may confound the study results, or may interfere significantly with
patient's participation in the study