Afatinib

Afatinib is an irreversible kinase inhibitor and binds to the kinase domains of EGFR (ErbB1), HER2 (ErbB2), and HER4 (ErbB4) to inhibit tyrosine kinase autophosphorylation. This results in a downregulation of ErbB signaling and subsequent inhibition of proliferation of cell lines expressing wild-type EGFR, selected EGFR exon 19 deletion mutations, or exon 21 L858R mutations. It also inhibited in vitro proliferation of cell lines overexpressing HER2. Overall, tumor growth was inhibited by Afatinib very effectively with low nanomolar IC50 values ranging from approximately 6nM to below 500 nM.