Discovery of novel Flt3 inhibitory chemotypes through extensive ligand-based and new structure-based pharmacophore modelling methods.

ABSTRACT

Flt3 is an oncogenic kinase involved in different types of leukemia. It is most prominently associated with acute myeloid leukemia (AML). Flt3-specific inhibitors have shown promising results in interfering with AML prompting us to model this interesting target. We implemented ligand-based, QSAR-guided, pharmacophore exploration combined with novel structure-based computational workflow based on docking-based comparative intermolecular contacts analysis (db-CICA) combined with homology modelling to explore the pharmacophoric features of 93 diverse cyclic Flt3 inhibitors. The resulting pharmacophore models were used as virtual search queries to scan the National Cancer Institute (NCI) database for novel Flt3 inhibitory leads. Ten hits of novel scaffolds were captured showing anti-Flt3 IC50 values ranging from 1.2 to 14.7 µM. Interestingly, six of them illustrated low micromolar and submicromolar potencies against the mutated active form of Flt3 (Flt3D835Y) and the related vascular endothelial growth factor receptor 2 (VEGFR2).