EGFR or HER2 inhibitor (EGFR/HER2 Inhibitor)

Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are members of the HER/ErbB family of receptor tyrosine kinases. They are characterized by an extracellular ligand-binding domain, a single transmembrane helix, and an intracellular tyrosine kinase domain. EGFR is activated by ligands such as EGF, TGF-α, leading to dimerization and autophosphorylation, which in turn initiates downstream signaling cascades involving MAPK, PI3K, and JAK/STAT pathways that control cell proliferation, survival, and migration[1][5][6][9]. HER2 does not have a known direct ligand and is typically activated through heterodimerization (especially with EGFR or HER3)[2][6]. Overexpression or activating mutations in EGFR and HER2 drive tumorigenesis in a variety of cancers. Both are established targets for monoclonal antibodies, small molecule kinase inhibitors, and antibody-drug conjugates, with predictors of response including EGFR-activating mutations and HER2 amplification. Resistance to therapy is a major clinical problem and can result from mutations, receptor crosstalk, and compensatory pathway activation[3][4][7].

Other names

ErbB-1ERBBHER1ERBB2HER2/neuCD340

Inhibition of tyrosine kinase activity (blocks ATP binding or kinase function); Blockade of ligand binding or receptor dimerization (monoclonal antibodies); Antibody-drug conjugate-mediated cytotoxicity; Induction of receptor degradation or downregulation