Inhibition of osimertinib-resistant epidermal growth factor receptor EGFR-T790M/C797S

Area of Science:

• Oncology
• Medicinal Chemistry
• Molecular Biology

Background:

• Precision medicine, particularly targeted therapies, has transformed EGFR-driven non-small cell lung cancer (NSCLC) treatment.
• Acquired drug resistance remains a significant challenge, limiting the long-term efficacy of current targeted agents.
• Development of novel inhibitors is crucial for overcoming resistance in specific cancer subtypes.

Purpose of the Study:

• To design and characterize novel covalent inhibitors targeting drug-resistant EGFR mutants.
• To investigate the efficacy of these inhibitors against EGFR-L858R/T790M and EGFR-L858R/T790M/C797S mutations.
• To elucidate the binding mode of these inhibitors using X-ray crystallography.

Main Methods:

• Synthesis of pyrrolopyrimidine-based covalent inhibitors.
• Biochemical and cellular assays for activity assessment.
• Kinase selectivity profiling and western blot analysis.
• X-ray crystallography to determine inhibitor-bound EGFR structures.

Main Results:

• Developed covalent inhibitors based on the pyrrolopyrimidine scaffold targeting EGFR-L858R/T790M.
• Demonstrated high activity against multi-drug resistant EGFR-L858R/T790M/C797S due to reversible binding kinetics.
• Obtained the first X-ray crystal structures of covalent inhibitors complexed with C797S-mutated EGFR.

Conclusions:

• Novel pyrrolopyrimidine covalent inhibitors are effective against key drug-resistant EGFR mutations in NSCLC.
• Reversible binding kinetics contribute to the high activity against triple-mutant EGFR.
• Structural insights from X-ray crystallography guide the development of next-generation EGFR inhibitors.