Phase I/II Trial of Enzalutamide and Mifepristone, a Glucocorticoid Receptor Antagonist, for Metastatic Castration-Resistant Prostate Cancer.

This is the first prospective trial of dual AR-GR antagonism in CRPC. Enzalutamide combined with mifepristone was safe and well tolerated but did not meet its primary endpoint. The development of more specific GR antagonists combined with AR antagonists, potentially studied in an earlier disease state, should be explored.