Virishibo-B (09887): The Phase II study of Vilisin™ for the treatment of biliary tract cancer completed the enrollment of all patients

According to the Zhitong Finance App, Weilizhibo-B (09887) announced that a phase II clinical study evaluating opatisumimab (Velisin™, a PD-L1/4-1BB bispecific antibody, LBL-024) for first-line treatment of advanced biliary tract cancer (BTC) has completed the enrollment of all 70 patients. In April 2026, the project successfully entered the expansion phase based on good safety and efficacy data exceeding expectations, and quickly completed the enrollment of all patients, fully demonstrating the efficient speed of clinical progress and continuous verification of the remarkable curative effects of Velisign™.

Although PD- (L) 1 immunotherapy combined with chemotherapy has become one of the first-line standard treatments for advanced biliary tract cancer in recent years, clinical benefits are still very limited. The current standard regimen, represented by pabolizumab in combination with chemotherapy and duvaliumab in combination with chemotherapy, has an objective response rate (ORR) of less than 30%. The median overall survival (OS) is only about 12-13 months, and the clinical needs are far from being met. Opatisumimab's potential as the cornerstone of IO2.0 pan-tumor therapy has been continuously verified in the three dimensions of anti-tumor activity, long-term survival benefit trends, and safety comparable to PD- (L) 1 monoclonal antibody. According to available data, following extrapulmonary neuroendocrine cancer (EP-NEC) and small cell lung cancer (SCLC), opatisumimab once again showed highly competitive curative efficacy in biliary tract cancer, a typical immune cold tumor, which is expected to push the curative effect of biliary cancer immunotherapy to a new high. Given that adenocarcinoma is the main pathological type of biliary tract cancer, combined with positive data previously observed in large cancer subtypes such as non-small cell lung cancer (NSCLC), opatisumimab has shown clear curative effects in both adenocarcinoma and squamous cell carcinoma, and its broad-spectrum anti-cancer potential continues to be verified.

The study was led by Academician Zhou Jian of Zhongshan Hospital affiliated to Fudan University and jointly promoted with many hospitals across the country. Data from the safety introduction period showed that the overall safety and tolerability of Velisin™ combined chemotherapy was good, and no new safety signals were found. The initial efficacy evaluation showed an encouraging trend in tumor shrinkage. Specific data will be announced at the European Society of Medical Oncology (ESMO) Annual Meeting to be held in Madrid, Spain from October 23 to 27, 2026.

Velisin™ is a bispecific antibody that targets both PD-L1 and 4-1BB, and is a pan-tumor IO2.0 cornerstone therapy with potential survival benefits. Using our self-developed platform X-body™, which has full intellectual property rights, Velisin™ can conditionally activate 4-1BB, remove PD-1/PD-L1 immunosuppression while enhancing T-cell activation regulated by 4-1BB, and achieve the effect of collaboratively eliminating tumors. Velisin™ has safety comparable to PD-1/PD-L1 inhibitors and has a stronger broad-spectrum cancer treatment potential, and has shown world-first (FIC) or best-in-class (BIC) potential in non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), extrapulmonary neuroendocrine cancer (EP-NEC), and biliary tract cancer (BTC).

As the world's first molecule targeting the co-stimulant receptor 4-1BB, which is already in the critical clinical phase of single-arm registration, Velisin™ is expected to be the first drug approved for the treatment of EP-NEC. Verisign™ has conducted 13 clinical studies on solid tumor indications in China, including 1 key registered clinical trial and 8 proof-of-concept studies, covering areas with high unmet clinical needs such as EP-NEC, NSCLC, SCLC, BTC, ovarian cancer (OC), esophageal squamous cell carcinoma (ESCC), liver cancer (HCC), gastric cancer (GC), triple-negative breast cancer (TNBC), and malignant melanoma. As an agonist, 4-1BB can reactivate apoptotic T cells and expand massively. It is particularly suitable for treating cold tumors where PD-1/PD-L1 is resistant or ineffective. In October 2024, Velisin™ was certified as a breakthrough therapeutic drug by CDE, and in November of the same year, it was certified as an orphan drug by the US Food and Drug Administration (FDA). In January 2026, Velisin™ received FDA Fast Track accreditation and can be used to treat EP-NEC and EU orphan drug certification.