Partner Therapeutics announced that the U.S. Food and Drug Administration has approved BIZENGRI for the treatment of adults with advanced, unresectable, or metastatic cholangiocarcinoma harboring a neuregulin 1 (NRG1) gene fusion whose disease has progressed following prior systemic therapy.
The approval marks the first targeted therapy specifically approved for patients with NRG1 fusion-positive cholangiocarcinoma, a rare and difficult-to-treat subtype of bile duct cancer associated with significant unmet medical need.
According to the company, the approval process was accelerated through the FDA’s Commissioner’s National Priority Voucher (CNPV) pilot program, which helped shorten the review timeline for the therapy. BIZENGRI had previously received both Breakthrough Therapy Designation and Orphan Drug Designation from the FDA for this indication, underscoring the urgent need for new treatment options in this patient population.
Pritesh J. Gandhi, Chief Development Officer at Partner Therapeutics, described the approval as a major milestone for patients and clinicians treating the disease.
He said the approval demonstrates meaningful tumor responses, durable clinical benefit, and a manageable safety profile observed in the company’s clinical trial program. Gandhi also noted that the expedited review process helped make the treatment available to patients more quickly.
The FDA’s decision was supported by results from the Phase 2 eNRGy clinical trial, a multicenter, open-label study evaluating zenocutuzumab in patients with advanced solid tumors harboring NRG1 gene fusions. The cholangiocarcinoma cohort included 22 patients with unresectable or metastatic disease, with 19 patients considered evaluable for efficacy analysis.
The trial’s primary efficacy endpoints were confirmed overall response rate (ORR) and duration of response (DOR). Investigators reported an ORR of 36.8%, meaning more than one-third of treated patients experienced tumor shrinkage or disappearance following therapy. Responses lasted from 2.8 months to 12.9 months, according to the study data.
The most commonly reported side effects occurring in at least 20% of patients included fatigue, diarrhea, musculoskeletal pain, abdominal pain, nausea, cough, shortness of breath, and decreased appetite. Researchers noted that fewer than 1% of patients discontinued treatment due to a drug-related adverse event, highlighting the therapy’s tolerability profile.
James Cleary, Director of Clinical Research in the Division of Gastrointestinal Oncology at the Dana-Farber Cancer Institute and Associate Professor at Harvard Medical School, said NRG1 fusion-positive cholangiocarcinoma remains a rare but clinically important subgroup of disease with poor outcomes and limited therapeutic options.
Cleary emphasized that the trial results reinforce the importance of comprehensive molecular testing, particularly tissue-based RNA sequencing, to identify patients with NRG1 gene fusions who may benefit from targeted therapies such as BIZENGRI.
BIZENGRI previously received accelerated approval in 2024 for patients with advanced non-small cell lung cancer and pancreatic adenocarcinoma harboring NRG1 gene fusions after systemic therapy. The therapy is also included in the National Comprehensive Cancer Network clinical practice guidelines for non-small cell lung cancer, pancreatic adenocarcinoma, and cholangiocarcinoma.