BPR1J-340

**BPR1J-340** is a potent and selective small molecule inhibitor of the FMS-like tyrosine kinase 3 (**FLT3**), an important therapeutic target in acute myeloid leukemia (AML), especially those with internal tandem duplications (FLT3-ITD). BPR1J-340 inhibits FLT3 kinase activity with an IC50 of approximately 25 nM and demonstrates strong anti-proliferative effects in cellular assays (GC50 ≈ 5 nM). The compound blocks FLT3 and STAT5 phosphorylation and induces apoptosis in FLT3-ITD(+) AML cells. In animal models, BPR1J-340 has shown significant tumor growth inhibition and even regression of large tumors in FLT3-ITD(+) AML xenografts. Combination studies reveal synergistic effects when BPR1J-340 is paired with the HDAC inhibitor vorinostat (SAHA), particularly via Mcl-1 downregulation. The drug is in the preclinical stage with studies supporting further development for AML therapeutics[1][2][3][5][7][9].