The Food and Drug Administration (FDA) has granted Orphan Drug designation to zenocutuzumab (MCLA-128; Merus) for the treatment of patients with pancreatic cancer.

Zenocutuzumab is a first-in-class bispecific antibody that binds to HER2 and HER3 receptors, thereby blocking the interaction of HER3 with its ligand neuregulin 1 (NRG1) or NRG1-fusion proteins.

In preclinical studies, zenocutuzumab showed strong inhibition of HER2/HER3 heterodimer formation and tumor growth in models harboring NRG1 fusions. Additionally, the investigational agent demonstrated promising early clinical responses in patients with previously treated pancreatic cancer harboring NRG1 gene fusions. Findings from the study showed that the 2 treated patients had significant tumor shrinkage, with a 44% reduction in tumor diameter at week 8 in 1 patient and a 22% reduction in tumor diameter at week 6 in the other patient.

The Company is currently enrolling patients in the global phase 1/2 eNRGy trial to evaluate the safety and antitumor activity of zenocutuzumab monotherapy in NRG1 fusion-positive solid tumors.

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“We are pleased with the progress we are making in our ongoing global clinical trial, and believe that Zeno has the potential to play a significant role in shifting the treatment paradigm for NRG1 fusion cancers from conventional chemotherapy to a personalized medicine approach,”  said Bill Lundberg, MD, President, CEO and Principal Financial Officer of Merus.

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1. Merus announces FDA orphan drug designation of zenocutuzumab for the treatment of pancreatic cancer. Published July 27, 2020. Accessed July 28, 2020. 

2. Bispecific antibody MCLA-128 shows clinical activity in patients with solid tumors harboring NRG1 gene fusions. Published October 27, 2019. Accessed July 29, 2020.