Merus Announces the Journal Publication of Petosemtamab Mechanism of Action

Core Insights - Merus N.V. announced the publication of the mechanism of action for petosemtamab, a bispecific antibody targeting EGFR and LGR5, in the journal "Cancers" [1][2] Company Overview - Merus is focused on developing innovative full-length human bispecific and trispecific antibody therapeutics, known as Multiclonics, which exhibit features similar to conventional human monoclonal antibodies [5] - Petosemtamab, also known as MCLA-158, is a low-fucose human full-length IgG1 antibody designed to target EGFR and LGR5, employing three independent mechanisms of action [6] Clinical Development - Petosemtamab has shown substantial clinical activity in recurrent/metastatic head and neck squamous cell carcinoma (r/m HNSCC), with ongoing Phase 3 trials in both first-line and second/third-line settings [3][4] - A Phase 2 trial is currently evaluating petosemtamab in combination with standard chemotherapy for metastatic colon cancer (mCRC), with initial clinical data expected in the second half of 2025 [4] Mechanism of Action - Petosemtamab operates through three distinct mechanisms: blocking EGFR ligands, internalizing and degrading EGFR in LGR5+ cells, and activating the innate immune system via antibody-dependent cellular phagocytosis (ADCP) and enhanced antibody-dependent cellular cytotoxicity (ADCC) [2][6] Market Context - Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer globally, with over 930,000 new cases and more than 465,000 deaths reported in 2020, and the incidence is expected to rise by 30% by 2030 [7]