Abiraterone Acetate: Targeting Persistent Androgen Dependence in Castration-Resistant Prostate Cancer

Abiraterone acetate is the first second-line hormonal agent proven to improve survival in metastatic castration-resistant prostate cancer. It selectively inhibits cytochrome P450 17 (CYP17) alpha-hydroxylase and cytochrome(17,20) (C-17,C-20)-lyase, which are enzymes critical for androgen synthesis. Abiraterone acetate was initially approved in the United States in 2011 after demonstrating a 4-month survival benefit in docetaxel-refractory metastatic prostate cancer. The FDA recently expanded its indication for use in the pre-chemotherapy setting after it elicited significant delays in disease progression and a strong trend for increased overall survival in phase III studies. Ongoing investigations of abiraterone are evaluating its efficacy in earlier disease states, exploring its synergy in combination with other therapeutic agents, and assessing the necessity for administration of concurrent steroids and gonadal suppression. The identification and development of predictive biomarkers will optimize the incorporation of abiraterone into the management of advanced prostate cancer.