Imatinib is an orally-available, aminopyrimidine-based inhibitor of Abl, c-Kit, and PDGFR with cellular phosphorylation inhibition IC50 value of 0.1 uM. [1]

Focused studies on c-Kit show that Imatinib inhibits activity of both wild-type and mutant c-Kit, as well as c-Kit-dependent activation of Akt. [2] Furthermore, Imatinib completely suppresses activation of MAPK and the antiapoptotic effect of c-Kit activation.

Studies on the PDGF receptors show that Imatinib preferentially inhibits the both a and b isoforms, but not the closely related c-Fms, Flt3, KDR, Flt1, and TEK tyrosine kinases. [3] In addition, Imatinib inhibits stem cell factor-mediated cellular signalling, including ligand-stimulated receptor autophosphorylation and inositol phosphate formation.