A novel scaffold for EGFR inhibition: Introducing N-(3-(3-phenylureido)quinoxalin-6-yl) acrylamide derivatives

Clinical data acquired over the last decade on non-small cell lung cancer (NSCLC) treatment with small molecular weight Epidermal Growth Factor Receptor (EGFR) inhibitors have shown significant influence of EGFR point mutations and in-frame deletions on clinical efficacy. Identification of small molecules capable of inhibiting the clinically relevant EGFR mutant forms is desirable, and novel chemical scaffolds might provide knowledge regarding selectivity among EGFR forms and shed light on new strategies to overcome current clinical limitations. Design, synthesis, docking studies and in vitro evaluation of N-(3-(3-phenylureido)quinoxalin-6-yl) acrylamide derivatives (7a-m) against EGFR mutant forms are described. Compounds 7h and 7l were biochemically active in the nanomolar range against EGFR(wt) and EGFR(L858R). Molecular docking and reaction enthalpy calculations have shown the influence of the combination of reversible and covalent binding modes with EGFR on the inhibitory activity. The inhibitory profile of 7h against a panel of patient-derived tumor cell lines was established, demonstrating selective growth inhibition of EGFR related cells at 10 μM among a panel of 30 cell lines derived from colon, melanoma, breast, bladder, kidney, prostate, pancreas and ovary tumors.