ARV-771

ARV-771 is a potent BET PROTAC based on E3 ligase von Hippel-Lindau with K_ds of 34 nM, 4.7 nM, 8.3 nM, 7.6 nM, 9.6 nM, and 7.6 nM for BRD2(1), BRD2(2), BRD3(1), BRD3(2), BRD4(1), and BRD4(2), respectively^[1]. IC50 & Target:Kd: 4.7 nM (BRD2), 7.6 nM (BRD3), 7.6 nM (BRD4)^[1]
IC50: <1 nM (c-MYC protein)^[1] In Vitro:ARV-771, a small-molecule pan-BET PROTAC degrader, demonstrates dramatically improved efficacy in cellular models of CRPC as compared with BET inhibition. ARV-771 potently degrades BRD2/3/4 in 22Rv1 cells with a DC₅₀ less than 5 nM. c-MYC protein is a downstream effector of BET proteins. Treatment with ARV-771 results in depletion of c-MYC with an IC₅₀ of less than 1 nM. ARV-771 shows strong antiproliferative effect on 22Rv1, VCaP, and LnCaP95 cell lines. ARV-771 treatment has a pronounced effect on cell morphology consistent with apoptosis. FL-AR and AR-V7 mRNA are down-regulated upon treatment with 10 nM ARV-771 in VCaP cells. ARV-771 has an antiandrogenic effect on a number of AR-regulated genes in VCaP cells^[1]. In Vivo:Treatment of non castrated male Nu/Nu mice bearing AR-V7+ 22Rv1 tumor xenografts with daily subcutaneous injections of ARV-771 at 10 mg/kg for 3 d results in 37% and 76% down-regulation of BRD4 and c-MYC levels, respectively, in tumor tissue. A marked down-regulation in levels of AR-V7 is observed in the 22Rv1 tumors after ARV-771 treatment^[1].