Clifutinib

Clifutinib is an orally active and selective internal tandem duplication mutation of FMS-like tyrosine kinase 3 ( FLT3-ITD ) inhibitor with an IC₅₀ value of 15.1 nM. Clifutinib exerts strong antiproliferative effects on FLT3-ITD acute myeloid leukemia (AML) cell lines (MV-4-11: IC₅₀ = 1.5 nM; MOLM-13: IC₅₀ = 1.4 nM). Clifutinib inhibits the activity of FLT3-ITD kinase and blocks the downstream RAS/MAPK, PI3K/AKT, and JAK/STAT5 signaling pathways of FLT3. Clifutinib induces apoptosis of acute myeloid leukemia (AML) cells with FLT3-ITD mutations. Clifutinib demonstrates significant antitumor efficacy in mice bearing MV-4-11 or MOLM-13 xenografts. Clifutinib is promising for research of relapsed/refractory FLT3-ITD-positive acute myeloid leukemia ^[1].

In Vivo, Clifutinib (0.5-20 mg/kg, p.o., once daily, 8,10 or 21 days) demonstrates significant antitumor efficacy in NOD/SCID mice bearing MV-4-11 or MOLM-13 xenografts^[1].

In Vitro, Clifutinib (72 h) shows anti-proliferative activities against MV-4-11 AML cells and MOLM-13 cells, with IC50s of 1.5 nM and 1.4 nM, respectively^[1]. Clifutinib (9e, 0.1-1000 nM, 72 h) exhibits potent antiproliferative activity against Ba/F3 cells expressing FLT3 mutant isoforms, with IC₅₀ values of 0.9 nM (Ba/F3-FLT3-ITD), 4.1 nM (Ba/F3-FLT3-ITD-D835A), 5.8 nM (Ba/F3-FLT3-ITD-D835G), 47.6 nM (Ba/F3-FLT3-ITD-D835Y), 74.7 nM (Ba/F3-FLT3-ITD-D835 Del), 130.0 nM (Ba/F3-FLT3-ITD-D835V), 2.9 nM (Ba/F3-FLT3-ITD-D835N), 301.9 nM (Ba/F3-FLT3-ITD-D835I), 6.9 nM (Ba/F3-FLT3-ITD-N676D), 25.0 nM (Ba/F3-FLT3-ITD-G697R), 38.0 nM (Ba/F3-FLT3-ITD-Y842H), 21.8 nM (Ba/F3-FLT3-ITD-Y842R), 154.0 nM (Ba/F3-FLT3-ITD-F691L), 154.4 nM (Ba/F3-FLT3-ITD-F691I), 5.4 nM (Ba/F3-FLT3-D835Y), 10.9 nM (Ba/F3-FLT3-D835H), 37.4 nM (Ba/F3-FLT3-D835V), while showing no antiproliferative effect on parental Ba/F3 cells with IC₅₀ > 1000 nM^[1]. Clifutinib (1-10 μM, 72 h) exhibits significant antiproliferative activity only against FLT3-ITD+ leukemia cell lines MV-4-11 and MOLM-13 with IC₅₀ values of 0.0015 μM and 0.0014 μM, respectively, while showing minimal or no antiproliferative effects on FLT3-ITD-negative cell lines (RS4;11, HL-60, MOLT-4, RPMI8226, K562, NCI-H226, PC-3, DU 145, SK-OV-3, OVCAR-3, MCF-7, SW-620, COLO205, Caki-1, U87MG, U251) with IC₅₀ > 10 μM, and weak activity against NCI-H460, A2780, HCT116, 786-O cells with IC₅₀ values of 7.8 μM, 7.2 μM, 8.5 μM, 3.4 μM, respectively^[1]. Clifutinib (1-100 nM, 48-72 h) induces apoptosis in MV-4-11 cells in a dose-dependent manner^[1]. Clifutinib (1-1000 nM, 2 h) inhibits the phosphorylation of FLT3, ERK, AKT, and STAT5 in MV-4-11 cells in a dose-dependent manner without affecting total protein levels^[1].

References:
[1]. Liu B, et al. Discovery of FLT3-ITD Inhibitor Clifutinib: A Novel Biphenylacetylene Urea Derivative in Clinical Trials for the Treatment of Relapsed/Refractory FLT3-ITD+ Acute Myeloid Leukemia. J Med Chem. 2025 Apr 24;68(8):7955-7972.