HER2targeting

HER2targeting refers to therapeutic strategies directed at the human epidermal growth factor receptor 2 (HER2), a receptor tyrosine kinase encoded by the ERBB2 gene. HER2 amplification or overexpression drives tumor growth in a subset of cancers, most notably breast and gastric cancers.

Mechanism and testing: HER2 amplification drives signaling via receptor dimerization; testing uses immunohistochemistry (IHC) and in situ hybridization (FISH or SISH) to confirm overexpression or amplification.

Therapies include monoclonal antibodies (trastuzumab, pertuzumab), antibody-drug conjugates (ado-trastuzumab emtansine, trastuzumab deruxtecan), and tyrosine kinase inhibitors (lapatinib, neratinib, tucatinib).

They are used in adjuvant, neoadjuvant, and metastatic settings depending on cancer type.

Resistance and safety: Resistance may arise from receptor truncation or downstream pathway activation; cardiotoxicity is a key risk, with diarrhea or liver toxicity also reported for several agents.

Outlook: The HER2-targeting field has improved outcomes for HER2-positive cancers, and ongoing research seeks to overcome resistance and broaden indications.