Enzalutamide in men with prostate cancer resistant to docetaxel and abiraterone.

247 Background: Since FDA approval in 2011, abiraterone (Zytiga) has supplanted docetaxel as preferred first-line treatment for metastatic castrate-resistant prostate cancer. In August 2012 enzalutamide (Xtandi) was FDA-approved for the treatment of castrate-resistant prostate cancer after docetaxel (Taxotere). We performed a retrospective chart review at a large medical oncology clinic specializing in prostate cancer to determine the PSA response rates of enzalutamide administered to men who had previously progressed on both abiraterone and docetaxel. This report includes some patients who participated in the Astellas/Medivation-sponsored Early Access Program; however, it represents the author’s independent clinical experience. Methods: Enzalutamide was administered at a dose of 160 mg daily. Patients were subsequently followed with monthly physical examination, PSA and routine blood tests. No hepatotoxicity or seizures occurred. Men were considered evaluable for PSA response if they received enzalutamid...