2-Pyrimidinamine, 5-chloro-N-[3-cyclopropyl-5-[[(3R,5S)-3,5-dimethyl-1-piperazinyl]methyl]phenyl]-4-(6-methyl-1H-indol-3-yl)-

HM43239 is an orally active small molecule inhibitor of FLT3 that selectively inhibits not only FLT3 wild type, ITD mutants or TKD mutations, but also FLT3 ITD/TKD double mutations. HM43239 directly inhibits the kinase activity of FLT3 as a reversible Type I inhibitor and effectively modulates downstream p-STAT5 and p-ERK. HM43239 also demonstrated inhibition of SYK, JAK1/2 and TAK1, known to be involved in tumor cell proliferation and/or differentiation HM43239 monotherapy induced dose-dependent regression of tumor growth in FLT3 wild-type and FLT3 mutated leukemia cancer cell line.

HM43239 potently inhibited the growth of AML cell lines harboring FLT3 ITD mutation, such as MV4-11 (IC50: 1.3 nM), MOLM-13 (5.1 nM) and MOLM-14 (2.9 nM). Furthermore, HM43239 effectively inhibited the phosphorylation levels of FLT3 and of downstream kinases related with cell proliferation._x000D_ _x000D_ Reference: Cancer Res. 2018 July 1;78(13_Supplement):804. https://doi.org/10.1158/1538-7445.AM2018-804

Furthermore, the combination treatment of HM43239 with various reagents (e.g., IAP inhibitor, chemotherapy, etc) demonstrated synergistic efficacy in mouse models, xenografted with both MV-4-11 and MOLM-13 cell lines without any significant toxicity._x000D_ _x000D_ Reference: Cancer Res. 2019 July 1;79(13_Supplement):1293. https://doi.org/10.1158/1538-7445.AM2019-1293

HM43239 is an orally active and selective FLT3 inhibitor with IC50s of 1.1 nM, 1.8 nM and 1.0 nM for FLT3 WT, FLT3 internal tandem duplication (ITD) and FLT3 D835Y kinases, respectively.