Prostate-specific antigen testing has not only led to an earlier diagnosis of prostate cancer, but also to an earlier identification of hormone-refractory prostate cancer (HRPC). Many patients identified early with HRPC may receive first-line taxane-based chemotherapy. Patients who progress after first-line chemotherapy are still quite healthy and desire further therapy. No proven treatment options exist for the second-line treatment of HRPC. Finding new agents that are active in the second-line setting and identifying relevant outcome variables and predictive pretreatment variables are crucial in improving survival and quality of life for this patient population.