6-Aryl and Heterocycle Quinazoline Derivatives as Potent EGFR Inhibitors with Improved Activity toward Gefitinib-Sensitive and -Resistant Tumor Cell Lines

A group of novel anilinoquinazoline derivatives with variable aryl and heterocyclic substituents at position6 were synthesized and tested for their EGFR-inhibitory activity. Aryl and heterocyclic rings were attached to the quinazoline scaffold through different linkages such as imine, amide, and thiourea. Most of the aryl and heterocyclic derivatives showed potent inhibition of wild-type EGFR with IC50 values in the low nanomolar range. Among these, thiourea derivatives 6a, 6b and compound 10b also retained significant activity toward the gefitinib-insensitive EGFR(T790M/L858R) mutant, displaying up to 24-fold greater potency than gefitinib. In addition, cell growth inhibitory activity was tested against cancer cell lines with wild-type (KB cells) and mutant EGFR (H1975 cells). Several compounds including 6a were found to be more potent than the reference compound gefitinib toward both cell lines, as was the case for compound 10b against H1975 cells. Therefore, compounds 6a and 10b in particular may serve as new leads for the development of inhibitors effective against wild-type EGFR as well as gefitinib-resistant mutants.