An orally available non-steroidal, lyase-selective inhibitor of the steroid 17-alpha-hydroxylase/C17,20 lyase (CYP17A1 or CYP17), with potential anti-androgenic and antineoplastic activities. Upon oral administration, CYP17 inhibitor VT-464 selectively inhibits the enzymatic activity of the cytochrome P450 C17,20 lyase in both the testes and adrenal glands, thereby inhibiting androgen production. This may decrease androgen-dependent growth signaling and may inhibit cell proliferation of androgen-dependent tumor cells. The cytochrome P450 enzyme CYP17A1, localized to the endoplasmic reticulum, exhibits both 17alpha-hydroxylase and 17,20-lyase activities; it plays a key role in the steroidogenic pathway. The lyase-selective activity of VT-464 prevents the increased synthesis of mineralocorticoids that is normally seen with non-selective CYP17 inhibitors, which also inhibit the 17-alpha-hydroxylase activity of CYP17A1.