UTRECHT, The Netherlands and CAMBRIDGE, MA, USA I September 30, 2024 I Merus N.V. (Nasdaq: MRUS) (Merus, the Company, we, or our), a clinical-stage oncology company developing innovative, full-length multispecific antibodies (Biclonics® and Triclonics®), today announced that the first patient has been dosed in the Company’s phase 3 trial evaluating the efficacy and safety of petosemtamab, a Biclonics® targeting EGFR and LGR5, in combination with pembrolizumab, compared to pembrolizumab as first line (1L) therapy for patients with PD-L1+ recurrent/metastatic head and neck squamous cell carcinoma (r/m HNSCC), referred to as the LiGeR-HN1 trial.

Merus has confirmed through feedback with the U.S. Food and Drug Administration (FDA) that petosemtamab 1500 mg every two weeks is appropriate for further development in HNSCC as monotherapy, and in combination with pembrolizumab.

“Based on our strong phase 2 clinical data reported previously for petosemtamab in HNSCC both as monotherapy and in combination with pembrolizumab, I continue to be confident that petosemtamab has the opportunity to become a new standard of care across r/m HNSCC and potentially beyond,” said Bill Lundberg, M.D., President, Chief Executive Officer of Merus. “Our recently announced alignment with the FDA on phase 3 dose, and excellent execution to date has allowed us to promptly initiate our registration trials in 1L and 2/3L HNSCC.” 

More details of the trial can be found at clinicaltrials.gov.  

About LiGeR-HN1
LiGeR-HN1, a phase 3 trial, will evaluate the safety and efficacy of petosemtamab in combination with pembrolizumab, compared to pembrolizumab in 1L PD-L1+ r/m HNSCC patients. The trial is open to adult patients eligible to receive pembrolizumab as 1L monotherapy with tumors expressing PD-L1, CPS ≥1. The primary endpoints are overall response rate as assessed by BICR based on RECIST v1.1 and overall survival. Secondary endpoints are duration of response and progression free survival. Merus plans to enroll approximately 500 patients in the trial.  

About Petosemtamab
Petosemtamab, or MCLA-158, is a Biclonics® low-fucose human full-length IgG1 antibody targeting the epidermal growth factor receptor (EGFR) and the leucine-rich repeat containing G-protein-coupled receptor 5 (LGR5). Petosemtamab is designed to exhibit three independent mechanisms of action including inhibition of EGFR-dependent signaling, LGR5 binding leading to EGFR internalization and degradation in cancer cells, and enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) activity.

About Head and Neck Cancer
Head and neck squamous cell carcinoma (HNSCC) describes a group of cancers that develop in the squamous cells that line the mucosal surfaces of the mouth, throat, and larynx. These cancers begin when healthy cells change and grow in an unchecked manner, ultimately forming tumors. HNSCC is generally associated with tobacco consumption, alcohol use and/or HPV infections, depending on where they develop geographically. HNSCC is the sixth most common cancer worldwide and it is estimated that there were more than 930,000 new cases and over 465,000 deaths from HNSCC globally in 2020.1 The incidence of HNSCC continues to rise and is anticipated to increase by 30% to more than 1 million new cases annually by 2030.2 HNSCC is a serious and life-threatening disease with poor prognosis despite currently available standard of care therapies.
Sung et al. CA Cancer J Clin, 71:209-49, 2021; Johnson, D.E., Burtness, B., Leemans, C.R. et al. Head and neck squamous cell carcinoma. Nat Rev Dis Primers 6, 92 (2020)

About Merus N.V.
Merus is a clinical-stage oncology company developing innovative full-length human bispecific and trispecific antibody therapeutics, referred to as Multiclonics®. Multiclonics® are manufactured using industry standard processes and have been observed in preclinical and clinical studies to have several of the same features of conventional human monoclonal antibodies, such as long half-life and low immunogenicity. For additional information, please visit Merus’ website, X, and LinkedIn.

SOURCE: Merus