Novel mutant-selective EGFR kinase inhibitors against EGFR T790M

The clinical efficacy of epidermal growth factor receptor (EGFR) kinase inhibitors in EGFR-mutant non-small-cell lung cancer (NSCLC) is limited by the development of drug-resistance mutations, including the gatekeeper T790M mutation (1-3). Strategies targeting EGFR T790M with irreversible inhibitors have had limited success and are associated with toxicity due to concurrent inhibition of wild-type EGFR (4,5). All current EGFR inhibitors possess a structurally related quinazoline-based core scaffold and were identified as ATP-competitive inhibitors of wild-type EGFR. Here we identify a covalent pyrimidine EGFR inhibitor by screening an irreversible kinase inhibitor library specifically against EGFR. T790M. These agents are 30- to 100-fold more potent against EGFR. T790M, and up to 100-fold less potent against wild-type EGFR., than quinazoline-based EGFR. inhibitors in vitro. They are also effective in murine models of lung cancer driven by EGFR. T790M. Co-crystallization studies reveal a structural basis for the increased potency and mutant selectivity of these agents. These mutant-selective irreversible EGFR kinase inhibitors may be clinically more effective and better tolerated than quinazoline-based inhibitors. Our findings demonstrate that functional pharmacological screens against clinically important mutant kinases represent a powerful strategy to identify new classes of mutant-selective kinase inhibitors.
EGFR kinase inhibitors, gefitinib and erlotinib, are effective clinical therapies for NSCLCs that harbour activating mutations in the EGFR kinase domain (1,6). The most common EGFR mutations, L858R. and de1E746_A750, [...]