LEXINGTON, Mass., February 20, 2026 — New findings from a post hoc analysis of the ongoing eNRGy trial reveal that continued treatment with zenocutuzumab beyond radiographic progression delivers sustained clinical benefit in patients with neuregulin 1 fusion-positive (NRG1+) non-small cell lung cancer (NSCLC). Presented at the 2026 International Association for the Study of Lung Cancer Targeted Therapies of Lung Cancer Meeting, the data highlight the therapeutic potential of extending targeted therapy use in a rare molecular subset with historically limited treatment options.

Science Significance

The analysis provides important biological and clinical insight into the heterogeneity of tumor progression in NRG1+ NSCLC. Zenocutuzumab, a HER2/HER3 bispecific antibody, is designed to block NRG1 fusion-driven signaling by inhibiting receptor dimerization and downstream oncogenic pathways. Among 27 evaluable patients treated beyond RECIST progression, 81% experienced oligoprogression, suggesting localized resistance rather than systemic therapeutic failure. Median drug exposure extended to nearly 10 months, compared with approximately seven months prior to progression. Notably, several patients maintained therapy for prolonged periods, including one exceeding 23 months beyond progression and another approaching four years of total treatment duration. These findings reinforce the scientific rationale for targeted therapy continuation in molecularly selected populations, particularly where disease progression remains spatially limited and biologically heterogeneous.

Regulatory Significance

Zenocutuzumab-zbco (BIZENGRI®) previously received U.S. FDA accelerated approval for advanced NRG1 fusion-positive NSCLC and pancreatic cancer following progression on prior therapy. The new evidence may inform confirmatory trial design required for full regulatory conversion. Accelerated approvals depend on verification of long-term clinical benefit, and treatment-beyond-progression analyses provide supportive real-world and investigational data. Additionally, the findings underscore the regulatory importance of comprehensive genomic profiling, particularly combined DNA and RNA next-generation sequencing, to identify rare actionable fusions such as NRG1.

Business Significance

From a commercial strategy perspective, Partner Therapeutics continues to strengthen zenocutuzumab’s clinical value proposition within precision oncology markets. Rare fusion-driven cancers represent high-unmet-need segments with premium reimbursement potential and strong physician adoption when efficacy is demonstrated. Expanding the therapy’s utility beyond initial progression could extend treatment duration, increase market penetration, and reinforce lifecycle management strategies. Moreover, positioning zenocutuzumab within biomarker-defined lung cancer subsets aligns with the broader industry shift toward tumor-agnostic and fusion-targeted biologics.

Patients’ Significance

For patients with NRG1+ NSCLC — a population often resistant to conventional chemotherapy and immunotherapy — the data offer renewed hope. Continued therapy beyond progression enabled durable disease control without additional safety burden, and no discontinuations due to adverse events were reported. In several cases, local interventions such as radiotherapy or surgical resection allowed patients to remain on treatment, highlighting a multidisciplinary care model. The approach may translate into extended survival, improved symptom control, and preserved quality of life for individuals facing limited therapeutic alternatives.

Policy Significance

Health systems and oncology policy frameworks are increasingly adapting to precision medicine paradigms. Evidence supporting treatment continuation beyond progression may influence reimbursement models, clinical guidelines, and sequencing strategies in rare biomarker-driven cancers. Policymakers must also address equitable access to advanced molecular diagnostics, as identification of NRG1 fusions remains dependent on sophisticated genomic testing infrastructure. Ensuring coverage for such testing is critical to realizing the full public-health value of targeted biologics.

The eNRGy trial analysis positions zenocutuzumab as a promising long-term disease management option for NRG1 fusion-positive lung cancer, particularly in the post-progression setting. By demonstrating sustained efficacy, tolerability, and extended treatment exposure, the findings deepen the therapeutic narrative around fusion-targeted antibodies. As confirmatory trials advance and genomic screening expands, zenocutuzumab may play an increasingly central role in redefining outcomes for patients with rare, treatment-resistant NSCLC.

Source: Partner Therapeutics press release