JNJ-1250132 (RWJ-66826) is an orally active and potent steroidal progesterone receptor (PR) antagonist, with an IC 50 of 1.3 nM. JNJ-1250132 inhibits binding of the receptor to DNA in vitro. JNJ-1250132 is a potent competitive inhibitor of binding to the human glucocorticoid receptor (GR) ( IC 50 =0.50 nM) and the rat androgen receptor (AR) ( IC 50 =5.6 nM), and was a weak inhibitor of binding to human Estrogen receptor (ER) ( IC 50 >3000 nM).