Inclusion Criteria:

• Patients must be/have the following for entry into the study:
• Willing and able to provide written informed consent
• Written Authorization for Use and Release of Health and Research Study Information (USA sites only) or Data Protection Consent (European sites only) has been obtained
• Age ≥ 18 years and male
• Histologically or cytologically confirmed adenocarcinoma of the prostate, but not with neuroendocrine differentiation or of small cell histology
• Prior chemotherapy for prostate cancer with regimen(s) containing paclitaxel or docetaxel
• Documented PSA progression according to PSAWG eligibility criteria (Appendix 1) with a PSA > 20 ng/mL
• On-going androgen deprivation with serum testosterone < 50 ng/dL (< 2.0nM/L)
• Serum potassium ≥ 3.5 mmol/L
• Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 2. (Karnofsky Performance Status ≥ 50%) (Appendix 4)
• No history of adrenal insufficiency or hyperaldosteronism
• Any acute toxicities of prior chemotherapy, radiotherapy have resolved to a NCI CTCAE (version 3) grade of ≤ 1. Chemotherapy induced alopecia and grade 2 neuropathy are excluded from this consideration. (Appendix 3)
• No radiotherapy, chemotherapy or immunotherapy within 30 days of administration of the Cycle 1 Day 1
• No surgery or local prostatic intervention within 28 days of the first dose. In addition, any clinically relevant sequelae from the surgery must have resolved prior to Cycle 1 Day 1.
• Life expectancy > 12 weeks
• Able to swallow the CB7630 whole as a tablets
• Able to follow study instructions, accessible for treatment and follow-up, and likely to complete all study requirements

Exclusion Criteria:

• The following are criteria for exclusion from participating in the study:
• Active or uncontrolled autoimmune disease that may require corticosteroid therapy
• Serious or uncontrolled co-existent non-malignant disease, including active and uncontrolled infection
• Uncontrolled hypertension
• Hemoglobin ≤ 9.0 g/dL
• Abnormal liver function tests consisting of any of the following:

Serum bilirubin > 1.5 x ULN ALT > 2.5 x ULN AST > 2.5 x ULN

• Serum creatinine > 2.0 x UNL or a calculate creatinine clearance < 50 mL/min
• Clinically significant heart disease as evidenced by a myocardial infarction in the past twelve 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 two years prior to enrollment and after consultation with a cardiologist to insure that the disease is stable.
• Other malignancy within the previous 5-years other than basal cell or squamous cell carcinomas of skin with a >30% probability of recurrence within 12 months.
• History of gastrointestinal disorders (medical disorders or extensive surgery) which may interfere with the absorption of the study medication
• Current enrollment in an investigational drug or device study or participation in such a study within 30 days of Cycle 1 Day 1
• 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