NVP-BSK805 TRIHYDROCHLORIDE

Biochem/physiol Actions

NVP-BSK805 is a selective, ATP-competitive (Ki = 0.43 nM) Janus kinase 2 (JAK2) inhibitor (IC50 = 0.58 and 0.56 nM against full-length wild-type and V617F JAK2, respectively) with greatly reduced potency against TYK2, JAK3, JAK1 (IC50 = 10.76, 18.68, 31.63 nM against respective JAK homology domain 1) and >300-fold selectivity over a panel of 36 other kinases. BSK805 potently inhibits STAT5 phosphorylation (by >90% at 100 nM; MB-02 & SET-2 cells) and proliferation in JAK2V617F mutant cultures in vitro (GI50= 39-331 nM; 75% SET-2 growth inhibition at 150 nM) and in Ba/F3 JAK2V617F-bearing mice in vivo (150 mg/kg p.o.). BSK805 daily oral administration is also efficacious against rhEpo-induced splenomegaly and polycythemia in mice (50-100 mg/kg) and rats (25-50 mg/kg) with good pharmacokinetics and oral avilability.