Abiraterone or Enzalutamide in Chemotherapy-Naïve Metastatic CRPC

Abstract

The current standard of care for metastatic prostate cancer is androgen deprivation therapy (ADT); however, after 5 years, significant patients undergo disease progression despite hormonal manipulation and castrate testosterone levels [1, 2]. Multiple new treatment agents have been developed for men with metastatic castration-resistant prostate cancer (mCRPC) including chemotherapeutic agents, such as docetaxel and cabazitaxel [3–5]. Docetaxel and cabazitaxel are the only US Food and Drug Administration (FDA)-approved chemotherapeutic agents for the mCRPC treatment, decrease PSA levels, and palliate symptoms, but survival benefits are limited. Also, use of systemic chemotherapy generally be reserved for men with symptomatic mCRPC and may be limited by the presence of pre-existing medical conditions and the risk of developing adverse effects [6]. Because the androgen receptor (AR) activates PSA gene expression, more understanding of the role of the AR in prostate cancer progression has led to the improvement of treatment strategies to further suppress AR signaling in mCRPC [7]. Both abiraterone acetate and enzalutamide have been studied and shown to prolong overall survival in large phase III trials in the chemotherapy-naïve mCRPC settings.