GNE-781

GNE-781 is a highly potent and selective CBP inhibitor with an IC50 of 0.94 nM in TR-FRET assay. GNE-781 also inhibits BRET and BRD4(1) with IC50s of 6.2 nM and 5100 nμ, respectively.

GNE-781 is a highly advanced potent and selective bromodomain inhibitor of cyclic adenosine monophosphate response element binding protein, binding protein (CBP). GNE-781 reduces FOXP3 (forkhead box P3) transcript levels. Examination of a subset of bromodomains reveals that GNE-781 is exquisitely selective for CBP/P300 and is remarkably selective for CBP (5425-fold) and P300 (4250-fold). GNE-781 demonstrates an appropriate balance of cell potency, selectivity (5425-fold over BRD4(1)) [1].

GNE-781 is a highly potent and selective CBP inhibitor that is efficacious in a MOLM-16 AML xenograft model. GNE-781 displays antitumor activity in an AML tumor model and is also shown to decrease Foxp3 transcript levels in a dose dependent manner.GNE-781 shows moderate to low clearance in vivo in all species evaluated, with acceptable oral bioavailability. The effect of GNE-781 is determined in an in vivo PK/PD experiment using a MOLM-16 (adult AML cell line) xenograft mouse model. Single doses of GNE-781 are given at dose levels between 3 and 30 mg/kg in MOLM-16 tumor-bearing animals, and samples are collected at time points covering 2-24 h. Tumor RNA is generated and used to assess MYC transcript by quantitative RT-PCR relative to vehicle-treated animals. Suppression of MYC is observed at doses as low as 3 mg/kg at 2 and 8 h, with maximal suppression observed at 10 and 30 mg/kg at 2 h (87% and 88% inhibition, respectively). To evaluate the in vivo efficacy of GNE-781, MOLM-16 AML xenografts are established in SCID beige mice. Upon tumor establishment, dosing of GNE-781 is initiated with po doses of 3-30 mg/kg, twice daily (BID). Single-agent efficacy is observed at all doses, as evidenced by inhibition of MOLM-16 tumor growth. Tumor growth inhibition (%TGI) is 73%, 71%, and 89% at 3, 10, and 30 mg/kg, respectively. All doses of GNE-781 are well tolerated over the 21-day dosing window, with a maximal body weight loss of 3.7%[1].

[1]. Romero FA, et al. GNE-781, A Highly Advanced Potent and Selective Bromodomain Inhibitor of Cyclic Adenosine Monophosphate Response Element Binding Protein, Binding Protein (CBP). J Med Chem. 2017 Nov 22;60(22):9162-9183.