An orally bioavailable steroidal cortexolone derivative and antagonist of the androgen receptor (AR) and glucocorticoid receptor (GR), with potential antineoplastic activity. Upon oral administration, AR/GR antagonist CB-03-10 specifically binds to AR and GR, inhibits AR and GR activation, and prevents AR- and GR-mediated signaling. This leads to an induction of both extrinsic and intrinsic apoptotic pathways and inhibits cell growth in AR- and GR-overexpressing tumor cells. AR and GR are overexpressed in certain types of cancer cells and are involved in proliferation, survival and chemoresistance of tumor cells.