Flaig TW, et al. - This study was planned to determine the efficacy of abiraterone acetate with prednisone for metastatic prostate cancer in patients with suboptimal biochemical response to hormone induction. Although 5 responses were observed, this study did not meet its prescribed level of 6 prostate-specific antigen (PSA) responses of 0.2 ng/mL or lower. Compared with historical controls, this trial demonstrated encouraging overall survival and progression-free survival rates. Without any clear signal of any unexpected adverse effects, the therapy was generally well tolerated.