This document summarizes the results of a randomized clinical trial investigating the autologous cellular immunotherapy sipuleucel-T in patients with androgen dependent prostate cancer. The trial did not meet its primary endpoint of showing a statistically significant difference in time to biochemical failure between the sipuleucel-T and control arms. However, patients receiving sipuleucel-T did experience a 48% increase in prostate specific antigen doubling time following testosterone recovery compared to the control arm. Treatment with sipuleucel-T was also associated with robust and sustained T cell immune responses against the immunizing antigen. The treatment was generally well tolerated with fatigue, chills, and pyrexia being the most common adverse events reported.