Inclusion Criteria:

• Histologically documented evidence of prostate cancer (needle biopsy or prostatectomy). In the abscence of histologically documented evidence of prostate cancer, the diagnosis must be based on elevated serum PSA and metastatic lesions on bone scan.
• Progressive HRPC defined as a PSA increase over baseline of >25% or 5ng/ml or new lesions on bone/CT scan after conventional androgen deprivation and antiandrogen withdrawal. Evidence of metastatic disease based on positive CT or bone scan is not required.
• PSA of greater than or equal to 2ng/ml and serum total testosterone less than or equal to 50ng/ml
• Prior chemotherapy is permitted if discontinued > 4 weeks prior to starting therapy
• Prior therapy with estrogens is permitted but must have been discontinued > 4 weeks prior to registration
• ECOG Performance Status 0-2
• Adequate renal function, hepatic function, and bone marrow function as outlined in protocol
• ECG showing a normal QT interval

Exclusion Criteria:

• Prior therapy with ketoconazole or corticosteroids for HRPC
• Major surgery or radiation therapy within 4 weeks
• Strontium-89 or samarium-153 therapy within 4 weeks
• Thromboembolism in past 6 months
• Patients who are taking drugs that may further prolong QT intervals and present a known risk for Torsades de Pointes.
• Concomitant use of drugs known to be narrow therapeutic index CTP3A4
• Drugs that are sensitive CYP3A4 substrates
• Alcohol or drug dependence currently or in the last 6 months