Fedratinib

Fedratinib (TG-101348) is a potent, selective, ATP-competitive and orally active JAK2 inhibitor with IC₅₀s of 3 nM for both JAK2 and JAK2V617F kinase. Fedratinib shows 35- and 334-fold selectivity over JAK1 and JAK3, respectively. Fedratinib induces cancer cell apoptosis and has the potential for myeloproliferative disorders research^[1][2]. IC50 & Target: IC50: 3 nM (JAK2)^[1] In Vitro: Fedratinib (TG101348) inhibits proliferation of a human erythroblast leukemia (HEL) cell line that harbors the JAK2V617F mutation, as well as a murine pro-B cell line expressing human JAK2V617F (Ba/F3 JAK2V617F), with an IC₅₀ value of approximately 300 nM for either line. Proliferation of parental Ba/F3 cells was inhibited to a comparable level, with an IC₅₀ value of ∼420 nM^[1].
Exposure of these cells to Fedratinib (TG101348) (0.1 μM, 0.3 μM, 1 μM, 3 μM, and 10 μM) reduces STAT5 phosphorylation at concentrations that parallel the concentrations required to inhibit cell proliferation^[1].
Fedratinib (TG101348) (0.1 μM, 0.3 μM, 1 μM, 3 μM, and 10 μM) induces apoptosis in both HEL and Ba/F3 JAK2V617F cells in a dose-dependent manner^[1]. In Vivo: Fedratinib (TG101348; 60-120 mg/kg; oral gavage; twice daily; for 42 days; C57Bl/6 mice) trewatment shows a dose-dependent reduction in polycythemia and a marked dose-dependent reduction in splenomegaly of treated animals^[1].