JNJ-1250132

JNJ-1250132 (RWJ-66826) is an orally active and potent steroidal progesterone receptor (PR) antagonist, with an IC₅₀ 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) (IC₅₀=0.50 nM) and the rat androgen receptor (AR) (IC₅₀=5.6 nM), and was a weak inhibitor of binding to human Estrogen receptor (ER) (IC₅₀ >3000 nM)^[1]. In Vitro:JNJ-1250132 and Mifepristone (HY-13683) inhibits R5020 (HY-119384)-stimulated cell proliferation at similar half-maximal inhibitory concentrations (IC₅₀s of 0.19 nM and 0.17 nM, respectively)^[1]. In Vivo:JNJ-1250132 (10 mg/kg, oral, for seven days) inhibits Dexamethasone (HY-14648)-induced involution^[1].