Comparing the effect of traditional and novel tyrosine kinase inhibitors for epidermal growth factor receptor exon 20...

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Epidermal growth factor receptor (EGFR) exon 20 insertions are key drivers in non-small cell lung cancer (NSCLC).
• These mutations confer variable sensitivity to tyrosine kinase inhibitors (TKIs).
• Understanding the molecular mechanisms of TKI resistance in EGFR exon 20 insertion NSCLC is critical.

Purpose of the Study:

• To investigate the structural dynamics of wild-type EGFR and common exon 20 insertion mutants (ASV, SVD, NPH).
• To explore the binding mechanisms of osimertinib and mobocertinib with these EGFR variants.
• To elucidate the differential efficacy of these TKIs in NSCLC with EGFR exon 20 insertions.

Main Methods:

• Utilized molecular dynamics (MD) simulations to analyze protein dynamics.
• Assessed free energy landscapes to understand conformational changes.
• Examined drug-protein interactions, including hydrogen bonding and salt bridge formation.

Main Results:

• Both osimertinib and mobocertinib binding altered the free energy landscapes of ASV-, SVD-, and NPH-EGFR mutants.
• Mobocertinib formed additional interactions, including a hydrogen bond with the T793 gatekeeper residue.
• Mobocertinib reduced the conformational flexibility and eliminated energy minima observed with osimertinib binding in certain mutants.

Conclusions:

• Mobocertinib exhibits enhanced efficacy compared to osimertinib against specific EGFR exon 20 insertion mutations in NSCLC.
• Mobocertinib's distinct binding mode facilitates the restoration of the inactive EGFR state.
• These findings support mobocertinib as a promising therapeutic option for NSCLC patients with particular EGFR exon 20 insertion profiles.