Tandutinib is a potent antagonist of platelet-derived growth factor receptor β (PDGFRβ), FLT3, and c-Kit (IC50 = 200, 220, and 170 nM, respectively). It less potently inhibits macrophage colony-stimulating factor 1 receptor (IC50 = 3.4 μM) and does not significantly inhibit other tyrosine or serine/threonine kinases. Tandutinib blocks the growth of cells expressing an internal tandem duplication within the juxtamembrane domain of the FLT3 receptor, found in some acute myelogenous leukemia cells. It also impairs the growth of colon cancer cells through its actions on the c-Kit receptor. Tandutinib reverses multidrug resistance in vitro by impairing the efflux activity of the multidrug resistance protein 7.
