Figure 1.

Therapeutic strategies to target human epidermal growth factor receptor 2 (HER2): (1) HER2-targeted immunotoxins that combine a HER2-targeted component with a toxic component, such as HER2-affitoxin; (2) antibodies that directly target extracellular epitopes of HER2 include trastuzumab, pertuzumab, and trastuzumab-DM1 (T-DM1) antibody-drug conjugate; and (3) small molecule tyrosine kinase inhibitors (TKIs) of HER2 include the dual epidermal growth factor receptor/HER2 TKI lapatinib and the pan-ErbB TKI neratinib.