Zalutumumab is a human monoclonal antibody used primarily in the treatment of certain cancers, particularly head and neck squamous cell carcinomas. It works by binding to the epidermal growth factor receptor (EGFR), blocking the binding of epidermal growth factor (EGF) and other ligands, thereby inhibiting receptor activation. This suppression hinders downstream signaling pathways involved in tumor cell proliferation, survival, and metastasis. It has been investigated in patients with recurrent or metastatic head and neck cancer, especially in those who have not responded well to conventional therapies like chemotherapy or radiation. Zalutumumab may be used as a single agent or in combination with other treatments to enhance antitumor effects. Its targeted mechanism reduces damage to healthy cells, offering a more specific therapeutic approach compared to traditional cytotoxic drugs. Clinical studies have shown that zalutumumab can improve progression-free survival and disease control rates in selected patient populations. Due to its specificity, it also plays a role in diagnostic and research settings to study EGFR expression and pathway dynamics in tumor tissues.