NVP-BSK805 dihydrochloride

NVP-BSK805 dihydrochloride is an ATP-competitive JAK2 inhibitor, with IC50s of 0.48 nM, 31.63 nM, 18.68 nM, and 10.76 nM for JAK2 JH1 (JAK homology 1), JAK1 JH1, JAK3 JH1, and TYK2 JH1, respectively. JAK2 JH1|0.48 nM (IC50)|FL JAK2 V617F|0.56 nM (IC50)|FL JAK2 wt|0.58 nM (IC50)|TYK2 JH1|10.76 nM (IC50)|JAK3 JH1|18.68 nM (IC50)|JAK1 JH1|31.63 nM (IC50)

NVP-BSK805 dihydrochloride is a JAK2 inhibitor, with IC50s of 0.48 nM, 31.63 nM, 18.68 nM, and 10.76 nM for JAK2 JH1 (JAK homology 1), JAK1 JH1, JAK3 JH1, and TYK2 JH1, respectively. NVP-BSK805 inhibits the full-length wild-type JAK2 (FL JAK2 wt) and FL JAK2 V617F activity, with IC50s of 0.58 ± 0.03 and 0.56 ± 0.04 nM. NVP-BSK805 is ATP-competitive, with aclculated Ki of 0.43 ± 0.02 nM. NVP-BSK805 suppresses the growth of JAK2V617F-bearing acute myeloid leukemia cell lines with GI50 of <100 nM. NVP-BSK805 blocks the STAT5 phosphorylation at ≥100 nM concentrations, and shows a bias for JAK2 over JAK1 and JAK3 inhibition in the JAK2V617F-mutant cell lines[1]. NVP-BSK805 (5 μM) improves P-gp inhibitory activity. NVP-BSK805 increases sensitization of drug-resistant KBV20C cancer cells to VIC treatment at 10 μM, and such an effect is more effective than a 5 μM dose[2].

NVP-BSK805 (150 mg/kg, p.o.) blocks STAT5 phosphorylation, splenomegaly, and leukemic cell spreading in a Ba/F3 JAK2V617F cell-driven mouse model. NVP-BSK805 (50, 75, and 100 mg/kg, p.o.) also suppresses rhEpo-mediated polycythemia and splenomegaly in BALB/c mice[1].

[1]. Baffert F, et al. Potent and selective inhibition of polycythemia by the quinoxaline JAK2 inhibitor NVP-BSK805. Mol Cancer Ther. 2010 Jul;9(7):1945-55. [2]. Cheon JH, et al. The JAK2 inhibitors CEP-33779 and NVP-BSK805 have high P-gp inhibitory activity and sensitize drug-resistant cancer cells to vincristine. Biochem Biophys Res Commun. 2017 Sep 2;490(4):1176-1182.