CP8754

CP8754 is an orally active, selective human progesterone receptor (hPR) antagonist that blocks progesterone-mediated signaling pathways. CP8754 competitively inhibits the binding of [³H]-progesterone to hPR. And in vitro, CP8754 inhibits progesterone-dependent exogenous luciferase and endogenous alkaline phosphatase expression; while in vivo, CP8754 inhibits rabbit endometrial transformation. CP8754 does not significantly bind to human glucocorticoid receptors (hGR), estrogen receptors (hER), or rat androgen receptors (rAR). CP8754 can be used in the study of progesterone-related diseases such as breast cancer, endometriosis, uterine fibroids, and meningioma, as well as hormone-dependent tumors^[1]. In Vitro:CP8754 (10^-11-10^-6 M; 16-20 h) exhibits pure progesterone receptor antagonist activity in T47D-pMAMneo-LUC cells (inhibiting luciferase expression) and T47D cells (inhibiting alkaline phosphatase expression), with an IC₅₀ of 109 nM for inhibiting alkaline phosphatase expression^[1]. In Vivo:CP8754 (2.5-10 mg/kg; subcutaneous injection; once daily; for 5 consecutive days) shows dose-dependent anti-progestogenic activity in immature female rabbits pretreated with estrogen and challenged with progesterone^[1].
CP8754 (10-60 mg/kg/day; oral administration; once daily; 5 days), when combined with progesterone, shows dose-dependent anti-progestogenic activity in an endometrial transformation model using estrogen-pretreated immature female rabbits, with lower efficacy than that of subcutaneous injection^[1].