Novel mutant-selective EGFR kinase inhibitors against EGFR T790M

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• Epidermal growth factor receptor (EGFR) kinase inhibitors are crucial for treating EGFR-mutant non-small-cell lung cancer (NSCLC).
• Drug resistance, particularly the T790M mutation, limits the clinical efficacy of current EGFR inhibitors.
• Existing quinazoline-based inhibitors target wild-type EGFR, leading to toxicity and limited success against resistant mutations.

Purpose of the Study:

• To identify novel EGFR inhibitors with high selectivity for the T790M resistance mutation.
• To develop a new class of covalent inhibitors that overcome resistance mechanisms in NSCLC.
• To explore alternative scaffolds to the traditional quinazoline-based EGFR inhibitors.

Main Methods:

• Screening of an irreversible kinase inhibitor library against EGFR T790M.
• In vitro biochemical assays to determine potency against mutant and wild-type EGFR.
• In vivo efficacy studies in murine models of EGFR T790M-driven lung cancer.
• Co-crystallization studies to elucidate the structural basis of inhibition.

Main Results:

• Identification of covalent pyrimidine EGFR inhibitors with 30- to 100-fold greater potency against EGFR T790M compared to quinazoline-based inhibitors.
• These novel inhibitors demonstrated up to 100-fold reduced potency against wild-type EGFR in vitro.
• Demonstrated efficacy in preclinical murine models of lung cancer driven by the EGFR T790M mutation.

Conclusions:

• Covalent pyrimidine inhibitors represent a new class of mutant-selective irreversible EGFR kinase inhibitors.
• These agents show potential for improved clinical efficacy and better tolerability compared to existing quinazoline-based drugs.
• Functional screening against mutant kinases is a powerful strategy for discovering novel, selective kinase inhibitors.