FDA approved Partner Therapeutics’ Bizengri (zenocutuzumab-zbco) for adults with advanced, unresectable, or metastatic cholangiocarcinoma harboring a neuregulin 1 gene fusion whose disease has progressed following prior systemic therapy.

The approval expands the role of precision oncology in rare gastrointestinal cancers, where treatment options remain limited and outcomes are often poor.

Cholangiocarcinoma associated with NRG1 fusions represents fewer than 1% of cases, but patients frequently lack other actionable driver mutations and historically have had few targeted treatment alternatives.¹

What was the approval based on?

Bizengri’s approval was supported by data from the Phase II eNRGy trial, a multicenter, open-label study evaluating Bizengri in advanced solid tumors harboring NRG1 gene fusions.¹ Among 22 patients with unresectable or metastatic NRG1-positive cholangiocarcinoma enrolled in the study, 19 were evaluable for efficacy. The therapy demonstrated a confirmed overall response rate of 36.8%, with durations of response ranging from 2.8 to 12.9 months.¹

“Today’s FDA approval of Bizengri for NRG1 fusion-positive cholangiocarcinoma is a historic milestone for patients who have had no approved targeted therapy,” said Pritesh J. Gandhi, chief development officer at Partner Therapeutics. “The results demonstrate meaningful tumor responses, durable benefit, and a favorable tolerability profile, and we are grateful that the FDA’s Commissioner’s National Priority Voucher pilot program greatly reduced the review time, helping bring this treatment to patients more quickly.”

The approval was expedited through the FDA’s Commissioner’s National Priority Voucher program, an initiative designed to accelerate review timelines for therapies addressing significant unmet medical needs, and was awarded to Bizengri on May 6^th, 2026.²

Bizengri was initially granted accelerated approval in 2024 for patients with NRG1-positive non-small cell lung cancer and pancreatic adenocarcinoma following prior systemic therapy. The latest approval further broadens the therapy’s reach across multiple tumor types driven by the rare fusion.

Bizengri had also previously received both Breakthrough Therapy and Orphan Drug designations for NRG1-positive cholangiocarcinoma.¹

Safety findings in the study were consistent with prior experience for the therapy, with the most common adverse reactions included fatigue, diarrhea, musculoskeletal pain, abdominal pain, nausea, cough, dyspnea, and decreased appetite.¹ Less than 1% of patients discontinued treatment due to treatment-related adverse events.

“NRG1 fusion–positive cholangiocarcinoma represents a rare but clinically important subset of disease with limited therapeutic options and poor outcomes,” said James Cleary, MD, PhD, director of clinical research in the division of gastrointestinal oncology at Dana-Farber Cancer Institute. “These data further highlight the essential role of comprehensive molecular testing, particularly tissue-based RNA-based sequencing, to reliably detect gene fusions such as NRG1 and ensure patients are appropriately identified for targeted therapy.”

Why is Bizengri’s approval important?

The approval underscores growing momentum around biomarker-driven oncology development, particularly for low-frequency genomic alterations that span multiple cancers.

For cholangiocarcinoma specifically, the approval adds another targeted option to a market that has increasingly shifted toward molecular stratification, with therapies aimed at FGFR2, IDH1, HER2, and now NRG1 alterations reshaping treatment strategies for subsets of patients with advanced disease.

Sources

1. Partner Therapeutics Announces FDA Approval of BIZENGRI® (Zenocutuzumab-zbco) for NRG1 Fusion-Positive Cholangiocarcinoma Following Receipt of FDA Commissioner's National Priority Voucher Partner Therapeutics May 11, 2026 https://www.prnewswire.com/news-releases/partner-therapeutics-announces-fda-approval-of-bizengri-zenocutuzumab-zbco-for-nrg1-fusion-positive-cholangiocarcinoma-following-receipt-of-fda-commissioners-national-priority-voucher-302767356.html
2. Partner Therapeutics Announces Receipt of FDA Commissioner’s National Priority Voucher for BIZENGRI® (Zenocutuzumab-zbco) in NRG1 Fusion-Positive Cholangiocarcinoma Partner Therapeutics May 6, 2026 https://www.partnertx.com/partner-therapeutics-announces-receipt-of-fda-commissioners-national-priority-voucher-for-bizengri-zenocutuzumab-zbco-in-nrg1-fusion-positive-cholangiocarcinoma/