Inclusion Criteria:

- Histologically documented adenocarcinoma of the prostate, clinically refractory or
resistant to hormone therapy, as documented by progression following at least one
hormonal therapy, which must include orchiectomy or ongoing treatment with
gonadotropin releasing hormone (GnRH) agonists

- Prostate specific antigen (PSA) evidence for progressive prostate cancer

- Patients who were withdrawn from anti-androgen therapy less than 6 months prior to
inclusion in the study require one PSA higher than the last pre-withdrawal PSA or 2
increases in PSA documented after the post-withdrawal nadir >=4 weeks from treatment
withdrawal if treated with flutamide and >=6 weeks if treated with bicalutamide or
nilutamide

- Eastern Cooperative Oncology Group (ECOG) performance status score = 0-1

- Laboratory values within protocol-defined parameters

- Systolic blood pressure <160 and diastolic blood pressure <100 mmHg documented on at
least 3 different days

- Ongoing gonadal androgen deprivation therapy with luteinizing hormone-releasing
hormone (LHRH) analogues or orchiectomy

- Castrate testosterone level <50 ng/dl or <2.00 nmol/L (nmol/L x 28.8 = ng/dL)

- Normal baseline adrenocorticotropic hormone (ACTH) stimulation test (this criteria
will be removed if no evidence of adrenocortical insufficiency is observed in the
dose escalation phase)

- Life expectancy of >=12 weeks

- Agrees to protocol-defined use of effective contraception

Exclusion Criteria:

- Prior cytotoxic chemotherapy for prostate cancer (including estramustine, docetaxel
and mitoxantrone). All other systemic chemotherapy must have been completed at least
2 years prior to enrollment

- Prior therapeutic radionucleotide therapy (except Radium 223) for prostate cancer

- Local therapy including external beam radiotherapy, brachytherapy, cryotherapy, or
high-intensity focused ultrasound to the prostate bed within 4 weeks of start of
study

- Prior ketoconazole, aminoglutethimide, or treatment with any investigational
anticancer agent, including systemic corticosteroids for the treatment of prostate
cancer, within 4 weeks of start of study

- Patients receiving any other hormonal therapy, including any dose of megestrol
acetate (Megace), Proscar (finasteride), any herbal product known to decrease PSA
levels (eg, saw palmetto and PC-SPES), or any systemic corticosteroid must
discontinue the agent for at least 4 weeks prior to enrollment

- Treatment with any investigational anticancer agent within 4 weeks of start of study.

- Patients on stable doses of bisphosphonates that show subsequent tumour progression
may continue on this medication; however, patients are not allowed to initiate
bisphosphonate therapy within two weeks prior to starting therapy or throughout the
study

- No supplements or complementary medicines/botanicals are permitted while on protocol
therapy, except for any combination of the following: conventional multivitamin
supplements, selenium, soy supplements

- Patients with serious or uncontrolled co-existent non-malignant diseases, or active
or uncontrolled infection

- Patients with central nervous system disease and/or brain metastases

- No currently active second malignancy other than non-melanoma skin cancer

- Clinical and/or biochemical evidence of hyperaldosteronism

- Patients with well controlled hypertension requiring medication will be allowed after
the dose escalation stage is completed

- NYHA Class III or IV congestive heart failure

- Myocardial infarction within the 6 months prior to start of study

- No active or uncontrolled autoimmune disease that may require corticosteroid therapy
during protocol treatment

- Major surgery or significant traumatic injury within 4 weeks of start of study