LEXINGTON, Mass., July 2, 2026
Partner Therapeutics (PTx) has announced the publication of pivotal results from the Phase 2 eNRGy clinical trial evaluating BIZENGRI® (zenocutuzumab-zbco) in patients with NRG1 fusion-positive advanced cholangiocarcinoma in the prestigious Journal of Clinical Oncology (JCO). The publication reinforces the scientific evidence supporting the recent U.S. Food and Drug Administration (FDA) approval of BIZENGRI for adults with advanced unresectable or metastatic cholangiocarcinoma harboring an NRG1 gene fusion following progression after prior systemic therapy. The peer-reviewed findings demonstrate that zenocutuzumab delivers meaningful and durable anti-tumor activity, favorable progression-free survival, and an encouraging safety profile in a patient population that has historically faced limited therapeutic options and poor clinical outcomes. The publication further validates the importance of precision oncology and comprehensive molecular profiling in identifying patients who may benefit from targeted therapies for rare genetic alterations.
Phase 2 eNRGy Trial Demonstrates Durable Clinical Benefit
The multicenter, open-label Phase 2 eNRGy trial evaluated zenocutuzumab in adults with advanced solid tumors carrying NRG1 gene fusions, including 22 patients with advanced cholangiocarcinoma, of whom 19 were evaluable for efficacy. Most participants had previously received systemic treatment, with some undergoing as many as six prior treatment lines. The study reported an investigator-assessed Overall Response Rate (ORR) of 36.8%, while the Clinical Benefit Rate reached 57.9%, reflecting patients who achieved either tumor response or prolonged disease stabilization exceeding six months.
The median Duration of Response was 7.4 months, and median Progression-Free Survival reached 9.2 months, demonstrating sustained anti-tumor activity in this difficult-to-treat patient population. Researchers also highlighted that RNA-based Next-Generation Sequencing (NGS) detected 100% of NRG1 gene fusions, significantly outperforming DNA-based testing, which identified only 29%, reinforcing the importance of advanced molecular diagnostics for patient selection.
Targeted Therapy Offers Improved Safety and Precision Oncology Approach
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Beyond efficacy, BIZENGRI demonstrated an encouraging safety profile, with most treatment-related adverse events limited to Grade 1 or Grade 2 severity. The most frequently reported adverse events included diarrhea, fatigue, and nausea, while no patients discontinued treatment because of treatment-related toxicity, highlighting its favorable tolerability compared with conventional chemotherapy options.
Zenocutuzumab is a bispecific antibody specifically engineered to block HER2/HER3 signaling driven by NRG1 fusion proteins, interrupting the molecular pathways responsible for tumor growth and proliferation. Because NRG1 gene fusions occur in less than 1% of cholangiocarcinoma cases, patients often remain without effective targeted therapies. The published findings emphasize the value of comprehensive tissue-based RNA sequencing for accurately identifying these rare yet highly actionable genetic alterations, enabling physicians to match patients with precision therapies that offer significantly improved clinical outcomes.
Publication Strengthens Expanding Precision Oncology Portfolio
The Journal of Clinical Oncology publication further strengthens the growing clinical evidence supporting BIZENGRI across multiple NRG1 fusion-positive cancers. The therapy previously received FDA accelerated approval for advanced non-small cell lung cancer (NSCLC) and pancreatic adenocarcinoma with NRG1 gene fusions, while the recent approval expands its use to cholangiocarcinoma, providing patients with an important new targeted treatment option.
Partner Therapeutics continues advancing precision oncology by focusing on therapies for rare molecularly defined cancers where significant unmet medical needs remain. The publication not only validates the therapeutic potential of zenocutuzumab but also highlights the increasing importance of molecular diagnostics, targeted biologics, and precision medicine in transforming cancer care through individualized treatment strategies based on tumor genetics rather than tumor location alone.
Source: Partner Therapeutics press release
