Novel irreversible epidermal growth factor receptor inhibitors by chemical modulation of the cysteine-trap portion.
Carmi C, Cavazzoni A, Vezzosi S, Bordi F, Vacondio F, Silva C, Rivara S, Lodola A, Alfieri RR, La Monica S, Galetti M, Ardizzoni A, Petronini PG, Mor M.
Irreversible EGFR inhibitors can circumvent acquired resistance to first-generation reversible, ATP-competitive inhibitors in the treatment of non-small-cell lung cancer. They contain both a driver group, which assures target recognition, and a warhead, generally an acrylamide or propargylamide fragment that binds covalently to Cys797 within the kinase domain of EGFR. We performed a systematic exploration of the role for the warhead group, introducing different cysteine-trapping fragments at position 6 of a traditional 4-anilinoquinazoline scaffold. We found that different reactive groups, including epoxyamides (compounds 3-6) and phenoxyacetamides (compounds 7-9), were able to irreversibly inhibit EGFR. In particular, at significant lower concentrations than gefitinib (1), (2R,3R)-N-(4-(3-bromoanilino)quinazolin-6-yl)-3-(piperidin-1-ylmethyl)oxirane-2-carboxamide (6) inhibited EGFR autophosphorylation and downstream signaling pathways, suppressed proliferation, and induced apoptosis in gefitinib-resistant NSCLC H1975 cells, harboring the T790M mutation in EGFR.