MEDI3379

MEDI3379 is a high-affinity, human monoclonal antibody that targets the **HER3** (ErbB3) receptor. Developed by **MedImmune** (a subsidiary of **AstraZeneca**), it is designed to block both ligand-dependent (induced by heregulin) and ligand-independent (induced by HER2/HER3 dimerization) activation of the HER3 signaling pathway. By binding to HER3, MEDI3379 prevents the recruitment of PI3K and subsequent activation of the AKT survival pathway, thereby inhibiting tumor cell proliferation and survival. It has been investigated primarily for the treatment of solid tumors, including head and neck squamous cell carcinoma (HNSCC), where HER3 signaling is often implicated in resistance to EGFR-targeted therapies.