LEXINGTON, MASSACHUSETTS, USA, April 14, 2026
Partner Therapeutics, Inc. has announced the submission of a supplemental Biologics License Application (sBLA) to the U.S. Food and Drug Administration (FDA) for BIZENGRI® (zenocutuzumab-zbco), seeking approval for the treatment of NRG1 fusion–positive cholangiocarcinoma, a rare and aggressive bile duct cancer with limited therapeutic options. The milestone is further reinforced by the therapy’s inclusion in updated NCCN Clinical Practice Guidelines, highlighting its growing clinical relevance in precision oncology and biomarker-driven cancer treatment.
Regulatory Submission Backed by Strong Clinical Data
The sBLA submission is supported by findings from the eNRGy clinical trial, which evaluated BIZENGRI in patients with NRG1 fusion–positive cancers, including cholangiocarcinoma. In this cohort, the therapy demonstrated a 36.8% overall response rate (ORR) and a median duration of response (DOR) of 12.9 months, as assessed by blinded independent central review. Importantly, treatment was generally well tolerated, with no discontinuations due to adverse events, reinforcing its favorable benefit-risk profile. These results highlight the potential of BIZENGRI to address a critical unmet need in targeted oncology, particularly for patients lacking effective treatment alternatives.
Precision Medicine Approach Targets NRG1 Fusion Cancers
BIZENGRI is a bispecific antibody designed to inhibit HER2/HER3 signaling pathways, which are activated by NRG1 gene fusions, a rare but actionable oncogenic driver. Unlike conventional therapies, this approach focuses on targeting the underlying molecular mechanisms of tumor growth, enabling a more personalized treatment strategy. The therapy has already received accelerated approval in the United States for NRG1 fusion–positive non-small cell lung cancer and pancreatic cancer, demonstrating its broader applicability across multiple tumor types. The inclusion of BIZENGRI in NCCN Guidelines as a Category 2A and 2B recommendation further supports its role in clinical decision-making and guideline-driven oncology practice.
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Advancing Treatment Options for Rare and Aggressive Cancers
Cholangiocarcinoma remains a highly aggressive malignancy with poor prognosis, particularly in advanced stages where surgical options are limited. The identification of NRG1 gene fusions as actionable biomarkers has opened new avenues for targeted therapy development. BIZENGRI’s mechanism of action, which blocks HER2/HER3 dimerization and downstream signaling, offers a novel approach to controlling tumor progression. The emphasis on molecular testing, including RNA-based sequencing, is critical for identifying eligible patients and ensuring optimal therapeutic outcomes. This development reflects the growing importance of companion diagnostics and biomarker-driven treatment strategies in oncology drug development.
Implications for Regulatory and Clinical Practice
The submission of the sBLA marks a significant step in expanding the clinical use of BIZENGRI and underscores the importance of regulatory pathways such as supplemental applications in accelerating access to innovative therapies. The combination of regulatory submission, clinical evidence, and guideline inclusion positions BIZENGRI as a potential new standard of care for NRG1 fusion–positive cholangiocarcinoma. Furthermore, the development highlights the role of integrated bio-pharmaceutical strategies, including clinical trials, regulatory engagement, and post-approval evidence generation, in bringing targeted therapies to patients with rare cancers. The progress also reflects ongoing advancements in biologics manufacturing, quality compliance, and precision medicine frameworks.
The sBLA submission for BIZENGRI represents a critical milestone in the advancement of targeted biologic therapies for rare cancers, combining strong clinical data with regulatory and guideline support. With its innovative mechanism, demonstrated efficacy, and expanding clinical footprint, BIZENGRI has the potential to significantly improve outcomes for patients with NRG1 fusion–positive cholangiocarcinoma. As the regulatory review progresses, this development highlights the transformative impact of precision oncology and biomarker-driven drug development in modern bio-pharmaceutical innovation.
Source: Partner Therapeutics press release
