NVP-BSK805 dihydrochloride

NVP-BSK805 dihydrochloride is a potent and selective quinoxaline JAK2 inhibitor with IC50 values of 0.48, 0.56 and 0.58 nM for JAK2 JH1, FL JAK V617F and FL JAK2 wt respectively. Within the JAK family, NVP-BSK805 displays more than 20-fold selectivity towards JAK2 in vitro, as well as excellent selectivity in broader kinase profiling. The compound blunts constitutive STAT5 phosphorylation in JAK2(V617F)-bearing cells, with concomitant suppression of cell proliferation and induction of apoptosis. In vivo, NVP-BSK805 exhibited good oral bioavailability and a long half-life. The inhibitor was efficacious in suppressing leukemic cell spreading and splenomegaly in a Ba/F3 JAK2(V617F) cell-driven mouse mechanistic model. Furthermore, NVP-BSK805 potently suppressed recombinant human erythropoietin-induced polycythemia and extramedullary erythropoiesis in mice and rats.