 Background: There are nearly 30,000 deaths per year in the United States from prostate cancer, making this a large and important target patient population for new therapeutics. The mainstay of therapy for advanced prostate cancer is androgen deprivation therapy ADT. Although ADT is effective in the large majority of men with advanced prostate cancer, the favorable response to ADT is only transient. In hormone-refractory, metastatic prostate cancer the only effective systemic treatment is cytotoxic chemotherapy. The median duration of response to standard, taxane-based chemotherapy is approximately six months, and median survival in contemporary studies is only 16-18 months. Thus, there is an urgent need for new therapeutic agents to treat advanced prostate cancer. 