ATC Group: L01EH Human epidermal growth factor receptor 2 (HER2) tyrosine kinase inhibitors

Lapatinib, a 4-anilinoquinazoline, is an inhibitor of the intracellular tyrosine kinase domains of both EGFR (ErbB1) and of HER2 (ErbB2) receptors (estimated Ki^app values of 3nM and 13nM, respectively) with a slow off-rate from these receptors (half-life greater than or equal to 300 minutes). Lapatinib inhibits ErbB-driven tumour cell growth in vitro and in various animal models.

Neratinib is an irreversible pan–erythroblastic leukaemia viral oncogene homolog (ERBB) tyrosine kinase inhibitor (TKI) that blocks mitogenic growth factor signal transduction through covalent, high affinity binding to the ATP binding site of 3 epidermal growth factor receptors (EGFRs): EGFR (encoded by ERBB1), HER2 (encoded by ERBB2), and HER4 (encoded by ERBB4) or their active heterodimers with HER3 (encoded by ERBB3). This results in sustained inhibition of these growth promoting pathways with HER2-amplified or over-expressed, or HER2-mutant breast cancers.

Tucatinib is a tyrosine kinase inhibitor of HER2. It is used in combination with trastuzumab and capecitabine for treatment of adult patients with advanced unresectable or metastatic HER2-positive breast cancer.