Definition

A humanized monoclonal antibody directed against the domain II of the extracellular domain of human epidermal growth factor receptor 2 (HER2; ErbB2; HER-2), with potential antineoplastic activity. Upon administration, anti-HER2 monoclonal antibody QL1209 targets and binds to HER2 on HER2-expressing tumor cells. This prevents HER2-mediated signaling and may lead to an inhibition of proliferation in HER2-expressing tumor cells. HER2, a tyrosine kinase receptor, is overexpressed by many cancer cell types.