Structure-Guided Design of C4-alkyl-1,4-dihydro-2H-pyrimido[4,5-d][1,3]oxazin-2-ones as Potent and Mutant-Selective Epidermal Growth Factor Receptor (EGFR) L858R/T790M Inhibitors.

Epidermal growth factor receptor (EGFR) T790M acquired drug-resistance mutation has become a major clinical challenge for the therapy of non-small cell lung cancer. Here, we applied a structure-guided approach on the basis of the previous reported EGFR inhibitor (compound 9), and designed a series of C4-alkyl-1,4-dihydro-2H-pyrimido[4,5-d][1,3]oxazin-2-one derivatives as novel mutant-selective EGFR inhibitors. Finally, the most representative compound 20a was identified, which showed high selectivity at both enzymatic and cellular levels against EGFR(L858R/T790M) (H1975 cell lines) over EGFR(WT) (A431 cell lines). The representative compound 20a also showed promising antitumor efficiency in the in vivo antitumor efficacy study of H1975 xenograft mouse model driven by EGFR(L858R/T790M). These results provide a new scaffold for the treatment of dual-mutant-driven non-small cell lung cancer.