FDA Grants Fast Track Designation to Zenocutuzumab to Treat Patients with NRG1+ Cancers

The FDA granted fast track designation to zenocutuzumab (Zeno) for the treatment of patients with metastatic solid tumors harboring NRG1 gene fusions (NRG1+ cancers) who have progressed with progression following on standard-of-care therapy, according to the drug’s developer Merus N.V. press release.¹

“Receiving Fast Track Designation is another important milestone for Zeno, and it validates the potential for addressing the unmet need of patients with NRG1[-positive] cancers,” Andrew Joe, MD, chief medical officer at Merus, said in a press release. “We continue to add clinical trial sites and enroll patients in the eNRGy trial and look forward to providing a substantial clinical program update at a major medical meeting in the second quarter of 2021.”

Research from a clinical proof-of-concept study presented at the 2019 AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics investigating the effectiveness of zenocutuzumab found that 3 patients harboring NRG1 fusion–positive solid tumors experienced tumor shrinkage and symptom improvement when treated with the bispecific antibody.²

The report, presented by Alison Schram, MD, of Memorial Sloan Kettering Cancer Center (MSKCC), detailed the experiences of 3 men who received zenocutuzumab treatment.

The first patient experienced a partial response, according to the investigators, with a 54% tumor diameter decrease after 5 months and a reduction in the pancreatic cancer biomarker CA 19-9 level (pancreatic cancer biomarker) reduction from a level of 262 units/mL to 50 units/mL.

The second patient experienced stable disease, with only a 25% tumor diameter reduction and lowering of the CA 19-9 level from 418 units/mL to 11 units/mL.

“Both patients remain on treatment 7-plus months into therapy and are tolerating it extremely well, with improvement in both disease-related symptoms and resolution of chemotherapy-associated toxicity,” reported Schram at the time of data readout.

As for the third patient, he received several doses of multiple chemotherapies and the HER2 inhibitor afatinib (Gilotrif) to treat his non­–small cell lung cancer (NSCLC) diagnosis, but the disease progressed. He experienced a partial response on zenocutuzumab after sequencing revealed a CD74–NRG1 fusion. There was a 41% reduction in his tumor diameter after 4 months.

Fast track designation is given by the FDA to “facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need.”

Following the designation, Merus is enrolling patients onto the Phase 1/2 eNRGy trial evaluating to assess zenocutuzumab as treatment for this group of patients. The patients will be split into 3 cohorts: NSCLC, pancreatic cancer, and other solid tumor diagnoses.

References:

1. Merus granted FDA fast track designation of zenocutuzumab for the treatment of patients with neuregulin 1 fusion cancers. news release. Utrecht, The Netherlands and Cambridge, MassachusettsMerus N.V. Published January 7, 2021. Accessed January 8, 2021.https://ir.merus.nl/news-releases/news-release-details/merus-granted-fda-fast-track-designation-zenocutuzumab-treatment.

2. MCLA-128 fights NRG1 fusion–positive cancers. Cancer Discov. 2019;9(12):1636. doi: 10.1158/2159-8290.CD-NB2019-128.