Small molecule allosteric modulators of mutant EGFR for non-small cell lung cancer therapy: An insight into design strategies and structure activity relationships.

Non-small cell lung cancer (NSCLC) is one of the deadliest malignancies, which is mostly caused by activating mutations in the epidermal growth factor receptor (EGFR). While EGFR tyrosine kinase inhibitors (TKIs) of the first, second, and third generations have improved patient outcomes, long-term efficacy is often compromised by acquired resistance caused by mutations like T790 M and C797S. The discovery and promise of small-molecule allosteric modulators, including both reversible allosteric, ATP dual targeting inhibitors and targeted protein degraders (PROTACs) that employ allosteric binding for mutant-selective EGFR degradation that target mutant EGFR in NSCLC treatment are thoroughly evaluated in this study. We detail advances in design strategies and structure-activity relationship (SAR) studies of various compounds, including marine-derived Clathrin analogues, and a spectrum of heterocyclic derivatives catalogued as C1-C19. The integration of in silico docking, molecular dynamics simulations, and in vitro/in vivo evaluations reveals that modifications to functional groups, heterocyclic scaffolds, and linker structures are critical for enhancing binding affinity and selectivity toward the allosteric site, while acknowledging that the proposed SAR trends and pharmacophore model require further experimental validation through co-crystallization and systematic analogue studies across different chemotypes. Notably, compounds C7, C8, C10, and C14 exhibit excellent superimposition with the benchmark allosteric inhibitor JBJ-09-063, underscoring their robust activity profiles and potential to overcome ATP-site mediated resistance. By bridging both the ATP and allosteric sites, these molecules offer a novel dual-targeting approach to counteract the heterogeneity of resistance mechanisms. Overall, the gathered data support the promise of allosteric modulators as a next-generation therapeutic strategy in EGFR-mutant NSCLC, and a 3-Point pharmacophoric framework is presented to guide future drug design aimed at maximising potency while limiting toxicity.