Inclusion Criteria:

          -  Histologically confirmed metastatic or advanced prostate adenocarcinoma that has been
             previously treated with docetaxel and has progressed during treatment of at least one
             hormonal therapy

          -  Two rising PSA levels greater than or equal to (>/=) 2 ng/mL measured >/= 1 week
             apart or radiographic evidence of disease progression in soft tissue or bone

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

          -  Adequate hematologic and organ function

          -  Documented willingness to use an effective means of contraception

        Exclusion Criteria:

          -  History of Type I or Type II diabetes mellitus requiring insulin

          -  New York Heart Association Class III or IV heart failure or Left ventricular ejection
             fraction < 50% or ventricular arrhythmia requiring medication

          -  Significant atherosclerotic disease, as evidenced by: unstable angina, history of
             myocardial infarction within 6 months prior to Day 1, or cerebrovascular accident
             within 6 months prior to Day 1

          -  Active autoimmune disease that is not controlled by nonsteroidal anti-inflammatory
             drugs or active inflammatory disease which requires immunosuppressive therapy

          -  Clinically significant history of liver disease

          -  History of adrenal insufficiency or hyperaldosteronism

          -  Phase II only: Previous therapy for prostate cancer with 17
             alpha-hydroxylase/C17,20-lyase inhibitors, including abiraterone

          -  Phase II only: Previous treatment for prostate cancer with Protein kinase B
             phosphatidylinositol 3 kinase and/or mammalian target of rapamycin inhibitors

          -  Need for chronic corticosteroid therapy of >/= 20 mg of prednisone per day or an
             equivalent dose of other anti inflammatory corticosteroids or immunosuppressant