Ilginatinib hydrochloride (NS-018 hydrochloride) is a highly active JAK2 inhibitor, with an IC50 of 0.72 nM, 46-, 54-, and 31-fold selectivity for JAK2 over JAK1 (IC50, 33 nM), JAK3 (IC50, 39 nM), and Tyk2 (IC50, 22 nM). Ilginatinib hydrochloride also inhibits Src-family kinases, especially SRC and FYN, and weakly inhibits ABL and FLT3 with 45- and 90-fold selectivity for JAK2, respectively. Ilginatinib hydrochloride shows potent inhibitory activity against cell lines JAK2V617F or MPLW515L mutations or the TEL-JAK2 fusion gene (expressing a constitutively activated JAK2) with IC50 of 11-120 nM, but has only minimal cytotoxicity against most other hematopoietic cell lines that have no constitutively activated JAK2.
Ilginatinib hydrochloride (0.5 μM) preferentially suppresses colony-forming unitgranulocyte/macrophage (CFU-GM) formation from myelodysplastic syndrome (MDS)-derived bone marrow mononuclear cells (BMMNCs). Ilginatinib hydrochloride (1 μM) suppresses the phosphorylation of STAT3 (the downstream kinase of JAK2) in CFU-GM-forming cells from MDS patients.