LEADS BIOLABS-B(09887): Updated Clinical and Translational Data for Vilixin in the Treatment of Extrapulmonary Neuroendocrine Carcinoma, Biliary Tract Cancer, and Colorectal Cancer Published at the 2026 European Society for Medical Oncology (ESMO) Congress

LEADS BIOLABS-B(09887) announced that updated clinical and translational data from four studies of Vilixin (opamtisumimab, a PD-L1/4-1BB bispecific antibody) were published at the 2026 European Society for Medical Oncology (ESMO) Congress. The presentations included: (i) a late-breaking abstract (LBA) oral presentation on Vilixin monotherapy for third-line or later extrapulmonary neuroendocrine carcinoma (EP-NEC); (ii) a preferred oral presentation on Vilixin combined with chemotherapy as first-line treatment for EP-NEC; (iii) a poster presentation on Vilixin combined with chemotherapy as first-line treatment for biliary tract cancer (BTC); and (iv) a translational research poster presentation on Vilixin for microsatellite stable (MSS) colorectal cancer (CRC). The updated data further validate that Vilixin can induce potent and durable anti-tumor immune responses, delivering long-tail survival benefits, particularly demonstrating standout performance in cold tumors such as EP-NEC and BTC. Translational research results in MSS CRC further support Vilixin's tumor-local conditional 4-1BB activation mechanism and its potential to convert immunologically "cold" tumors into "hot" tumors. Vilixin is a bispecific antibody targeting both PD-L1 and 4-1BB, with the potential to become a pan-tumor IO 2.0 backbone therapy with survival benefits. Currently, Vilixin has initiated clinical studies across 14 indications, including 1 single-arm pivotal registrational clinical study, 1 confirmatory Phase III clinical study, and 9 proof-of-concept studies, covering multiple major cancer types and "cold tumors." Among the 7 cancer types with existing clinical data support, Vilixin has demonstrated exceptional clinical value and broad therapeutic prospects, including extrapulmonary neuroendocrine carcinoma (EP-NEC), non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), biliary tract cancer (BTC), hepatocellular carcinoma (HCC), esophageal squamous cell carcinoma (ESCC), and ovarian cancer (OC). Developed using our independently developed X-body platform with full intellectual property rights, Vilixin achieves conditional activation of 4-1BB, enhancing 4-1BB-regulated T cell activation while relieving PD-1/PD-L1 immunosuppression, achieving a synergistic tumor-killing effect. Vilixin has safety comparable to PD-1/PD-L1 inhibitors and stronger broad-spectrum cancer treatment potential. Notably, activating 4-1BB can reactivate exhausted T cells and drive massive expansion, making 4-1BB-targeting therapies potentially suitable for treating immunologically "cold tumors" that are resistant or unresponsive to PD-1/PD-L1 inhibitors, and can deliver long-tail survival benefits. In October 2024, Vilixin received Breakthrough Therapy Designation from the NMPA; in November 2024, it received Orphan Drug Designation from the U.S. Food and Drug Administration (FDA). In January 2026, Vilixin received Fast Track Designation from the FDA and Orphan Drug Designation from the European Union. In September 2026, Vilixin received Orphan Drug Designation from Japan's Ministry of Health, Labour and Welfare (MHLW). In October 2026, it received Fast Track Designation from the FDA for first-line treatment of advanced BTC. In July 2026, the innovative biologic product marketing application for Vilixin was included in the NMPA's priority review and approval process, and was officially accepted in August 2026, with the potential to become the world's first approved 4-1BB antibody drug, the world's first approved agonist-class antibody drug, and the world's first approved treatment for EP-NEC.