Anti-EGFR Monoclonal Antibody (Panitumumab)

The EGFR (epidermal growth factor receptor) is a transmembrane receptor tyrosine kinase belonging to the ErbB/HER family. Under normal physiological conditions, upon binding to ligands such as epidermal growth factor, it activates downstream signaling pathways including the RAS-RAF-MEK-ERK and PI3K-AKT cascades, thereby regulating key cellular processes such as proliferation, survival, differentiation, and migration. However, when its gene harbors mutations (such as exon 19 deletions or the exon 21 L858R point mutation, which are commonly seen in non-small cell lung cancer) or undergoes overexpression, it leads to ligand-independent constitutive activation, driving tumor development and progression. Consequently, EGFR has become an important biomarker for targeted cancer therapy. Small-molecule tyrosine kinase inhibitors developed against mutant EGFR can effectively block its oncogenic signaling. Nevertheless, the emergence of resistance mutations (such as T790M and C797S) has spurred ongoing efforts to develop next-generation inhibitors and combination therapeutic strategies.