FDA Approves Zenocutuzumab in NRG1+ Cholangiocarcinoma Post Systemic Therapy

The FDA has approved zenocutuzumab-zbco (Bizengri) as a treatment for patients with cholangiocarcinoma harboring an NRG1 gene fusion who experienced disease progression on or after prior systemic therapy, according to a press release from the FDA.^1,2

The decision comes only 2 days after the FDA gave a Commissioner’s National Priority Voucher (CNPV) pilot program voucher to the agent in this specific population.³ Additionally, the agent received breakthrough therapy designation in October 2025 and orphan drug designation in February 2026, and in April 2026, the FDA accepted a supplemental biologics license application for zenocutuzumab in this patient population.^4-6

The approval was supported by findings from the phase 1/2 eNRGy trial (NCT02912949), which assessed zenocutuzumab in 19 evaluable patients with NRG1 fusion-positive cholangiocarcinoma.

The overall response rate (ORR) among those patients was 36.8% (95% CI, 16.3%-61.6%), with a duration of response ranging from 2.8 months to 12.9 months.

“Patients with this ultra-rare type of cancer desperately need new treatment options,” stated FDA Commissioner Marty Makary, MD, MPH, in the press release.¹ “Through the national priority voucher pilot program, the FDA is accelerating therapies for rare diseases with unmet medical needs, reviewing applications in significantly shortened timelines.”

Further results were most recently shared at the 2025 American Association for Clinical Research/National Cancer Institute/European Organisation for Research and Treatment of Cancer Meeting.⁷

The median progression-free survival (PFS) in this cohort was reported to be 9.2 months (95% CI, 3.9-11.4); the median overall survival was not estimable (NE; 95% CI, 16.1-NE), with a median follow-up of 15.2 months (range, 1.2-34.1).

Regarding safety, 59% of patients experienced a treatment-related adverse event (AE). Grade 3 or higher AEs included anemia (14%) and hypomagnesemia (9%), among others.

Zenocutuzumab is being recommended at an intravenous dose of 750 mg every 2 weeks until disease progression or unacceptable toxicity.

The prescribing label included warnings and precautions for infusion-related reactions/hypersensitivity/anaphylactic reactions, as well as interstitial lung disease, left ventricular dysfunction, and embryo-fetal toxicity.

The FDA noted that this is the seventh approval made under the CNPV pilot program. The agency plans to host a meeting on June 4, 2026, to solicit public feedback on various aspects of the program.

References

1. FDA grants seventh approval under the National Priority Voucher Pilot Program. News release. FDA. May 8, 2026. Accessed May 8, 2026. https://tinyurl.com/4da6z98x
2. FDA approves zenocutuzumab-zbco for advanced, unresectable or metastatic cholangiocarcinoma. News release. FDA. May 8, 2026. Accessed May 8, 2026. https://tinyurl.com/yce235jj
3. Partner Therapeutics announces receipt of FDA Commissioner’s National Priority Voucher for BIZENGRI (zenocutuzumab-zbco) in NRG1 fusion-positive cholangiocarcinoma. News release. Partner Therapeutics Inc. May 6, 2026. Accessed May 8, 2026. https://tinyurl.com/dnp66tty
4. Zenocutuzumab-zbco granted FDA breakthrough therapy designation for NRG1+ cholangiocarcinoma; data highlighting potential of zenocutuzumab-zbco in NRG1+ cholangiocarcinoma to be presented at AACR-NCI-EORTC. News release. Partner Therapeutics Inc. October 23, 2025. Accessed May 8, 2026. https://tinyurl.com/3f8883ys
5. Zenocutuzumab‑zbco receives FDA orphan drug designation for treatment of cholangiocarcinoma. News release. Partner Therapeutics Inc. February 5, 2026. Accessed May 8, 2026. https://tinyurl.com/ymstnwkw
6. Partner Therapeutics announces submission of supplemental biologics license application (sBLA) to FDA for Bizengri (zenocutuzumab-zbco) in NRG1 fusion positive cholangiocarcinoma and inclusion in updated NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). News release. Partner Therapeutics Inc. April 14, 2026. Accessed May 8, 2026. https://tinyurl.com/mrx43hbj
7. Schram AM, Cleary JM, Arnold D, et al. Zenocutuzumab efficacy and safety in advanced NRG1+ cholangiocarcinoma: analysis from the phase 2 eNRGy trial. Presented at: American Association for Cancer Research/National Cancer Institute/European Organisation for Research and Treatment of Cancer Conference on Molecular Targets and Cancer Therapeutics; October 22-26, 2025; Boston, MA.