SILVER SPRING, Maryland, May 8, 2026
The U.S. Food and Drug Administration (FDA) has approved Bizengri (zenocutuzumab-zbco) for the treatment of adults with advanced, unresectable, or metastatic NRG1 fusion-positive cholangiocarcinoma, providing the first targeted therapy specifically approved for this ultra-rare and aggressive bile duct cancer subtype. The approval was granted to Partner Therapeutics, Inc. and represents the seventh authorization issued under the FDA’s Commissioner’s National Priority Voucher (CNPV) pilot program, an initiative designed to accelerate regulatory review timelines for therapies addressing serious diseases with major unmet medical needs. The decision marks an important advancement in the rapidly evolving field of precision oncology, where treatments are increasingly developed around specific genetic mutations rather than traditional tumor classifications. Patients diagnosed with NRG1 fusion-positive cholangiocarcinoma often face poor survival outcomes and limited treatment options after standard therapies fail, making the approval particularly significant for both clinicians and the rare cancer community.
FDA Expands Precision Oncology Efforts for Rare Cancers
According to the FDA, Bizengri is now approved for patients whose NRG1 fusion-positive cholangiocarcinoma has progressed on or after prior systemic treatment. Cholangiocarcinoma is a highly aggressive malignancy that develops in the bile ducts and is frequently diagnosed at advanced stages where surgical intervention is no longer possible. NRG1 gene fusions are exceptionally rare genomic alterations but are recognized as important oncogenic drivers that promote tumor growth through activation of HER-family signaling pathways. The FDA stated that efficacy data supporting the approval were generated from a clinical study involving 19 patients with advanced NRG1 fusion-positive cholangiocarcinoma. Results demonstrated an overall response rate of 36.8%, with treatment responses lasting between 2.8 months and 12.9 months. Regulatory officials noted that the approval reflects increasing emphasis on biomarker-driven therapies capable of targeting genetically defined patient populations with limited existing treatment alternatives.
FDA Commissioner Marty Makary, M.D., M.P.H., emphasized that patients suffering from this ultra-rare cancer urgently need new therapeutic options and highlighted the role of the National Priority Voucher Program in accelerating access to innovative therapies. The FDA also confirmed that Bizengri previously received both Breakthrough Therapy Designation and Orphan Drug Designation, reflecting the therapy’s potential importance for patients facing serious and rare diseases. The agency continues expanding initiatives focused on accelerating approvals for precision medicines capable of addressing difficult-to-treat cancers through targeted molecular approaches.
Bizengri Targets NRG1-Driven Tumor Biology
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Bizengri is a bispecific HER2/HER3-directed antibody therapy engineered to block signaling pathways activated by NRG1 gene fusions, which are found across several solid tumor types including lung cancer, pancreatic cancer, and cholangiocarcinoma. By interrupting these signaling mechanisms, the therapy is designed to inhibit tumor growth and progression in cancers driven by abnormal NRG1 fusion activity. The approval further expands Bizengri’s clinical footprint following its earlier 2024 accelerated approval for NRG1 fusion-positive non-small cell lung cancer (NSCLC) and pancreatic adenocarcinoma. Industry observers view the expanding use of genomic profiling and molecular diagnostics as a major driver behind the growth of highly targeted oncology therapies capable of treating rare biomarker-defined cancers.
The FDA reported that serious side effects associated with Bizengri may include infusion-related reactions, interstitial lung disease/pneumonitis, and left ventricular dysfunction. The most commonly observed adverse reactions during clinical development included diarrhea, fatigue, musculoskeletal pain, nausea, dyspnea, rash, constipation, vomiting, abdominal pain, edema, and infusion-related reactions. Despite these risks, regulators concluded that the therapy’s benefit-risk profile supports approval for patients with limited available treatment options and aggressive disease progression.
National Priority Voucher Program Continues Expansion
The approval also represents another major milestone for the FDA’s Commissioner’s National Priority Voucher pilot program, which was established to support accelerated development and review of therapies addressing critical public health priorities and rare diseases. The program enables the FDA to shorten review timelines for selected therapies while maintaining regulatory standards related to safety, efficacy, and manufacturing quality. Regulatory experts believe the initiative could become increasingly influential for biotechnology and pharmaceutical companies developing innovative treatments for orphan diseases, genetically defined cancers, and severe unmet medical conditions.
The FDA announced that it will host a public meeting on June 4, 2026, to gather feedback regarding the implementation and future direction of the CNPV pilot program. Discussions are expected to include eligibility criteria, sponsor responsibilities, review procedures, operational structure, and long-term program expansion. Written public comments will also be accepted through June 29, 2026. As precision oncology continues reshaping cancer treatment strategies worldwide, programs such as the CNPV initiative may play an increasingly important role in accelerating patient access to novel targeted therapies like Bizengri.
Source: FDA press release
