seribantumab + cetuximab

Seribantumab + cetuximab is a combination of two monoclonal antibodies used in investigational studies for the treatment of EGFR-dependent cancers. **Seribantumab** is a fully human monoclonal antibody targeting HER3 (human epidermal growth factor receptor 3, also known as ERBB3), inhibiting its activation and downstream signaling, particularly in tumors reliant on HER2/HER3 and HRG-mediated pathways. **Cetuximab** is a chimeric (human/mouse) monoclonal antibody that targets the epidermal growth factor receptor (EGFR/ERBB1), competitively inhibiting ligand binding, receptor activation, and downstream proliferative signaling. The rationale for this combination is to overcome resistance to EGFR-directed therapies by simultaneously inhibiting both EGFR and HER3 pathways, especially since HER3/EGFR heterodimers can mediate resistance. The combination is in early clinical trials and has demonstrated typical EGFR-inhibitor-related toxicities, including rash, diarrhea, and mucositis[1][7].