U1-15

U1-15 is a humanized monoclonal antibody that targets the human epidermal growth factor receptor 3 (HER3, also known as ErbB3). Developed by U3 Pharma (now part of Daiichi Sankyo), U1-15 was designed to inhibit HER3 signaling by blocking the binding of its primary ligand, heregulin (HRG). By preventing ligand-induced activation, the antibody suppresses the downstream PI3K/AKT pathway, which is a critical driver of tumor cell growth, survival, and resistance to other therapies. While U1-15 shows potent activity in ligand-dependent cancer models (such as certain breast and melanoma cell lines), it has been noted in literature to be less effective in ligand-independent models where HER3 is constitutively activated through dimerization with HER2. It has primarily served as a reference molecule in the development of next-generation HER3 antagonists.

Other names

humanized anti-ErbB3 antibody U1-15anti-HER3 U1-15anti-HER-3 U1-15anti-HER 3 U1-15