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. 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.

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.