Definition

An orally bioavailable inhibitor of the receptor tyrosine kinase human epidermal growth factor receptor 2 (HER2; ErbB2; HER-2), with potential antineoplastic activity. Upon oral administration, zongertinib covalently binds to and inhibits the activity of both wild-type and HER2 mutants, including HER2 mutants with exon 20 insertion (ex20ins) mutations. This prevents HER2-mediated signaling and may lead to cell death in HER2-expressing tumor cells. HER2, a receptor tyrosine kinase overexpressed on a variety of tumor cell types, plays an important role in tumor cell proliferation and tumor vascularization.