XL019

XL019 is a potent, highly selective and reversible JAK2 inhibitor (IC₅₀ = 2.2 nM). Inhibits JAK1 (IC₅₀ = 134.3 nM), JAK3 (IC50 = 214.2 nM) and TYK2 (IC₅₀ = 348.3 nM) at higher concentrations. XL019 displays significant dose-dependent pharmacodynamic and antitumor effect in a mouse xenograft model.