FDA Accepts BLA for Pancreatic and Lung Cancer Therapy

The FDA has accepted for priority review Merus’s biologics license application (BLA) for zenocutuzumab (Zeno) to treat patients with non-small cell lung cancer and pancreatic cancer. The FDA’s target action date is in December 2024

The American Cancer Society predicts that in 2024, there will about 234,580 new cases of lung cancer and 66,440 people diagnosed with pancreatic cancer. NRG1 gene fusions are rare subtypes of these tumors, occurring in less than 1% of solid tumors.

Zeno is new type of bispecific antibody that is designed to target both HER2 and HER3 proteins and inhibit NRG1 binding. The company has on its website a video about how this works to impact tumor survival.

If approved, Zeno would be the first targeted therapy for a NRG1+ cancer.

The BLA is supported by data from the phase 1/2 eNRGy trial, an open-label study with multiple expansion cohorts. Phase 1 was a dose escalation study, which is complete. Phase 2 is dose expansion evaluating Zeno with various tumors with NRG1 fusions and is ongoing. The study aims to enroll 250 patients with NRG1 fusions, including non-small cell lung cancer and pancreatic cancer, as well as breast and cholangiocarcinoma (bile duct cancer).

The primary objective of phase 2 is to assess the magnitude of antitumor activity of Zeno. Key secondary objectives include durability of antitumor activity, as well as clinical benefit rate, duration of response, the time of onset of response, characterization of the safety and tolerability of Zeno, characterization of the PK profile of Zeno, immunogenicity of Zeno, and evaluation of progression-free survival and overall survival.

Initial results were presented at the European Society for Medical Oncology in October 2023. At data cutoff of July 31, 1023, the study enrolled 105 patients with non-small cell lung cancer that had NRG1 fusions; at the time of analysis, 87 patients had been treated with at least 24 weeks follow up. Ultimately the results of 79 patients were analyzed after eight were excluded.

Researchers found that patients had durable responses, with overall response rate of 37.2% and a median duration response of 14.9 months. There were no treatment-related discontinuations, and there was a low incidence of grade 3 or 4 treatment related adverse events.

Also presented were data from patients with pancreatic cancer. At the same data cut-off, 33 of 44 patients with pancreatic cancer NRG1 fusions were included in the analysis. In these patients, the overall response rate was 42.4% and the median duration of response was 9.1 months. Additionally, 27 patients experienced tumor reduction. Zeno was well tolerated; 6% of patients experienced grade 3 or 4 toxicities.