Allosteric ligand-driven smart nanoconjugates for mutation-selective EGFR targeting: A precision approach to overcoming tyrosine kinase inhibitor resistance.

The development of targeted therapies against epidermal growth factor receptor (EGFR) has transformed the clinical management of EGFR-driven malignancies, especially non-small cell lung cancer (NSCLC). However, the therapeutic benefit of ATP-competitive tyrosine kinase inhibitors (TKIs) is often undermined by acquired resistance mutations such as T790M and C797S, which either enhance ATP affinity or preclude covalent drug binding. Allosteric inhibition of EGFR has emerged as a promising alternative, leveraging cryptic, mutation-specific binding pockets to achieve superior selectivity and reduced off-target toxicity. Allosteric ligands, particularly those targeting the αC-helix adjacent clefts, have shown potent activity against drug-resistant EGFR isoforms but suffer from suboptimal pharmacokinetics and systemic stability. To overcome these limitations, smart nanoconjugates functionalized with allosteric inhibitors have been developed to enhance targeted delivery, improve intracellular trafficking, and facilitate stimuli-responsive drug release. These nanosystems are capable of co-delivering synergistic agents such as siRNA or CRISPR-Cas9 payloads, amplifying pathway suppression and delaying resistance onset. Surface modification strategies, including PEGylation and bioorthogonal ligand conjugation, further improve circulation half-life and tumor accumulation via active and passive targeting. This review systematically discusses the molecular basis of EGFR allosteric inhibition, engineering principles of nanocarrier platforms, including immunogenicity, scale-up feasibility, and regulatory complexities.