Epidermal growth factor receptor (EGFR) mutant variants (EGFR)

The Epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein and a member of the ErbB family of receptor tyrosine kinases (RTKs) [UniProt: P00533]. In its wild-type form, EGFR regulates essential cellular processes including growth, proliferation, and survival through the activation of downstream signaling cascades such as the MAPK/ERK and PI3K/Akt pathways [PubMed: 29463514]. However, specific mutations within the EGFR kinase domain lead to ligand-independent, constitutive activation of these pathways, driving oncogenesis [NCBI: NBK553090]. These mutant variants are particularly prevalent in non-small cell lung cancer (NSCLC), where they serve as both primary drivers of malignancy and critical therapeutic targets [PubMed: 30545357]. Therapeutic intervention primarily involves small-molecule tyrosine kinase inhibitors (TKIs) that compete with ATP for binding in the kinase domain, thereby halting signaling [PubChem: CID 123631]. While first- and second-generation TKIs effectively target sensitizing mutations like L858R and exon 19 deletions, the emergence of resistance mutations, most notably T790M, necessitated the development of third-generation inhibitors like osimertinib [PubMed: 28445385]. Ongoing clinical challenges include addressing rarer variants like exon 20 insertions and overcoming tertiary resistance mutations such as C797S [PubMed: 33633361].

Other names

ErbB-1HER1Proto-oncogene c-ErbB-1EGFR mutations

Selective inhibition of the intracellular tyrosine kinase domain of mutant EGFR to block downstream oncogenic signaling pathways, or monoclonal antibody-mediated inhibition of ligand binding and receptor dimerization.