Merus’ petosemtamab granted Breakthrough Therapy designation by FDA

Merus (MRUS) announced that the FDA has granted Breakthrough Therapy designation to petosemtamab in combination with pembrolizumab for the first-line treatment of adult patients with recurrent or metastatic programmed death-ligand 1 – PD-L1 – positive head and neck squamous cell carcinoma with combined positive score greater than or equal to 1. This second BTD designation follows the initial receipt of BTD and Fast Track designation for petosemtamab for the treatment of patients with r/m HNSCC whose disease has progressed following treatment with platinum-based chemotherapy and an anti-programmed cell death protein 1 antibody announced in May 2024 and August 2023, respectively. BTD is supported by updated data from the ongoing phase 1/2 open-label, multicenter trial evaluating petosemtamab in combination with pembrolizumab in 1L HNSCC expressing PD-L1. Data for this cohort initially demonstrated a 67% response rate among 24 evaluable patients. With this BTD, Merus plans to engage in these discussions with the FDA in an expedited manner toward a potential Biologics License Application submission.