PLX51107

PLX51107 is a potent and selective BET inhibitor, with K_ds of 1.6, 2.1, 1.7, and 5 nM for BD1 and 5.9, 6.2, 6.1, and 120 nM for BD2 of BRD2, BRD3, BRD4, and BRDT, respectively; PLX51107 also interacts with the bromodomains of CBP and EP300 (K_d, in the 100 nM range). IC50 & Target: Kd: 1.6 nM (BRD2-BD1), 2.1 nM (BRD3-BD1), 1.7 nM (BRD4-BD1), 5 nM (BRDT-BD1), 5.9 nM (BRD2-BD2), 6.2 nM (BRD3-BD2), 6.1 nM (BRD4-BD2), 120 nM (BRDT-BD2), ∼100 nM (CBP), ∼100 nM (EP300)^[1] In Vitro: PLX51107 is a potent and selective BET inhibitor, with K_ds of 1.6, 2.1, 1.7, and 5 nM for BD1 and 5.9, 6.2, 6.1, and 120 nM for BD2 of BRD2, BRD3, BRD4, and BRDT, respectively. PLX51107 also interacts with the bromodomains of CBP and EP300 (K_d, in the 100 nM range). PLX51107 (0.156-10 μM) suppresses the CpG-induced proliferation of primary chronic lymphocytic leukemia (CLL) cells. PLX51107 also causes accumulation of p21 and IκBα, reduces c-MYC level, and modulates proapoptotic and antiapoptotic proteins. PLX51107 selectively modulates CLL driver genes^[1]. In Vivo: PLX51107 (2 mg/kg, p.o.) inhibits splenomegaly by 75% in the Ba/F3 (murine IL3-dependent pro-B-cell line) splenomegaly mouse model, with the similar effect of 25 mg/kg OTX015. PLX51107 (20 mg/kg, qd, p.o.) exhibits potent antileukemic effects in disease models of aggressive chronic lymphocytic leukemia (CLL) and Richter transformation (RT) via oral administration once daily^[1].