Petosemtamab granted Breakthrough Therapy Designation by the U.S. FDA

• Petosemtamab granted BTD for the treatment of previously treated HNSCC

UTRECHT, The Netherlands and CAMBRIDGE, Mass., May 13, 2024 (GLOBE NEWSWIRE) -- Merus N.V. (Nasdaq: MRUS), a clinical-stage oncology company developing innovative, full-length multispecific antibodies (Biclonics and Triclonics) for cancer, today announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation (BTD) for petosemtamab for the treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) whose disease has progressed following treatment with platinum based chemotherapy and an anti-programmed cell death receptor-1 (PD-1) or anti-programmed death ligand 1 (PD-L1) antibody. This designation follows receipt of Fast Track Designation for petosemtamab for the treatment of patients with recurrent or metastatic HNSCC whose disease has progressed following treatment with platinum-based chemotherapy and an anti-programmed cell death protein 1 (anti-PD-1) antibody announced in August 2023.

BTD is supported by data from the ongoing phase 1/2 open-label, multicenter trial evaluating petosemtamab monotherapy in patients with advanced solid tumors, including previously treated (recurrent or metastatic) HNSCC (NCT03526835). Merus plans to provide updated efficacy, durability and safety data from this cohort in the second half of 2024.

BTD is intended to expedite the development and review of a medicine to treat a serious or life-threatening condition, where preliminary clinical evidence indicates that the drug may demonstrate substantial improvement on clinically significant endpoints over available therapies. BTD allows for more intensive FDA guidance on an efficient drug development program, an organizational commitment involving senior managers, and experienced review staff, as appropriate, in a collaborative, cross-disciplinary review, and eligibility for rolling review and priority review. With this BTD, Merus plans to engage in these discussions with the FDA in an expedited manner as we move toward our goal of a potential Biologics License Application (BLA) submission.

“We are excited and encouraged to receive BTD for petosemtamab which further validates its potential to become a new standard of care for patients with previously treated HNSCC,” said Ashley Pereira, Pharm.D. SVP of Regulatory Affairs at Merus. “We look forward to continued constructive conversations with the FDA as we move forward in our plan to initiate a phase 3 trial in previously treated HNSCC mid-2024 and prepare for a potential phase 3 trial evaluating the combination of petosemtamab and pembrolizumab in previously untreated patients.”