Leads Biolabs’ Opamtistomig (PD-L1/4-1BB Bispecific Antibody) Advances to Expansion Phase in First-Line Hepatocellular Carcinoma Following Positive Efficacy Signals
NANJING, China, Aug. 05, 2026 (GLOBE NEWSWIRE) -- Nanjing Leads Biolabs Co., Ltd. (“Leads Biolabs” or the “Company,” Stock Code: 9887.HK) today announced that its Phase II clinical study evaluating Opamtistomig (LBL-024), a proprietary PD-L1/4-1BB bispecific antibody, in combination with bevacizumab for the treatment of first-line hepatocellular carcinoma (HCC) has successfully completed the safety run-in phase assessment following expert review and has advanced into the expansion phase. The study is led by Professor Zhou Jian, President of Zhongshan Hospital, Fudan University, and Academician of the Chinese Academy of Sciences.
Preliminary clinical data demonstrated that Opamtistomig in combination with bevacizumab has shown encouraging anti-tumor activity and a favorable safety profile in patients with HCC, supporting further clinical evaluation in the expansion phase.
HCC represents a significant global health burden and is the fourth most common malignant tumor and the second leading cause of cancer-related mortality in China, with approximately 368,000 new cases and 317,000 deaths recorded annually. Due to its often insidious onset, fewer than 30% of patients are eligible for potentially curative treatment at diagnosis, making systemic anti-tumor therapies essential for patients with intermediate-to-advanced disease.
Currently, PD-1/PD-L1 inhibitors in combination with bevacizumab have become one of the first-line standard treatments for advanced HCC both in China and globally; however, median overall survival is only approximately 19 to 20 months, median progression-free survival is less than 7 months, and the objective response rate does not exceed 30%. These limitations highlight the urgent need for more effective and durable treatment strategies.
Opamtistomig has demonstrated promising efficacy signals and broad therapeutic potential across multiple tumor types, including extrapulmonary neuroendocrine carcinoma (EP-NEC), non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC) and biliary tract cancer (BTC). Powered by the proprietary X-body™ platform, which enables tumor-localized activation of 4-1BB signaling, Opamtistomig has maintained a favorable safety profile across nearly 800 treated patients, further supporting its potential as a next-generation IO 2.0 pan-tumor immunotherapy platform. The encouraging clinical findings in HCC further strengthen the clinical validation of Opamtistomig’s differentiated mechanism and therapeutic potential.
Executive Commentary
Dr. Charles Cai, Chief Medical Officer of Leads Biolabs, said: “Advancing this Phase II study of Opamtistomig in first-line HCC into expansion phase is an important milestone in validating its potential as a pan-tumor immunotherapy. While PD-1/PD-L1-based combination therapies have become the standard of care for first-line HCC, significant unmet medical needs remain. The encouraging efficacy signals observed with Opamtistomig in combination with bevacizumab provide further confidence in its potential to improve treatment outcomes for patients with HCC. We will continue to accelerate clinical development and global registration efforts to bring this innovative therapy to patients worldwide as quickly as possible.”
About HCC
According to data published by the World Health Organization (“WHO”), the global annual number of new HCC cases reached 865,000 in 2022, ranking sixth among malignant tumors, with 758,000 deaths, ranking third among malignant tumors. HCC is particularly prevalent in China, where it is the fourth most common malignant tumor and the second leading cause of cancer-related deaths. Although China’s population accounts for only 18.4% of the global population, the country accounts for 368,000 new HCC cases and 317,000 deaths annually, representing 42.5% and 41.8% of the global totals, respectively.
HCC is the predominant type of primary liver cancer, accounting for approximately 85% to 90% of cases. It has an insidious onset and is highly aggressive, with most patients diagnosed at an intermediate to advanced stage and a correspondingly poor prognosis. The five-year survival rate is 15% to 19% in North America, compared with only 12.1% in China, posing a serious threat to the health and lives of the Chinese population and making the reduction of the HCC disease burden a major public health issue requiring urgent attention in China.
About Opamtistomig
Opamtistomig (LBL-024) is emerging as a next-generation pan-cancer backbone therapy with potential overall survival (OS) benefit that simultaneously targets PD-L1 and the co-stimulatory receptor 4-1BB. Developed using Leads Biolabs’ proprietary X-Body bispecific platform, Opamtistomig is designed to simultaneously block PD-1/L1 immune suppression and conditionally activate 4-1BB, an agonist pathway, resulting in a potent and synergistic anti-tumor immune response. It has a safety profile comparable to PD-1/PD-L1 inhibitors and demonstrates broader-spectrum anti-cancer potential. To date, Opamtistomig has demonstrated first- or best-in-class potential in Phase II or registrational clinical trials across four indications: non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), biliary tract cancer (BTC), and extrapulmonary neuroendocrine carcinoma (EP-NEC).
As the first 4-1BB–targeting bispecific antibody globally to advance to a single-arm pivotal trial as monotherapy, Opamtistomig has been evaluated in 13 solid tumor indications in China, including 1 pivotal registration trial and 8 proof-of-concept studies. These cover EP-NEC, NSCLC, SCLC, BTC, ovarian cancer (OC), esophageal squamous cell carcinoma (ESCC), hepatocellular carcinoma (HCC), gastric cancer (GC), triple-negative breast cancer (TNBC), malignant melanoma, and other areas with high unmet medical needs.
Mechanistically, 4-1BB agonism can reactivate exhausted T cells and promote robust T-cell proliferation, offering significant promise for PD-1/PD-L1–resistant or immunologically “cold” tumors. Recognizing its clinical potential, Opamtistomig received Breakthrough Therapy Designation (BTD) from China’s National Medical Products Administration (NMPA) in October 2024, and Orphan Drug Designation (ODD) from the U.S. Food and Drug Administration (FDA) for the treatment of neuroendocrine carcinoma in November 2024. Additionally, in January 2026, Opamtistomig was granted Fast Track Designation (FTD) by the FDA and ODD by the European Commission for the treatment of EP-NEC, further underscoring its potential to address unmet medical needs in this patient population.
About Leads Biolabs
Founded in 2012, Leads Biolabs is a clinical-stage biotechnology company dedicated to the discovery, development, and commercialization of innovative therapies to address underserved medical needs in oncology, autoimmune, and other severe diseases both in China and globally.
Leads Biolabs is a front-runner in next-generation immuno-oncology treatments with a differentiated pipeline of 14 innovative drug candidates, including four clinical-stage drug candidates and one registration-stage asset.
The Company adopts a science-driven R&D approach and has successfully established comprehensive R&D capabilities spanning antibody discovery and engineering, in vivo and in vitro efficacy evaluation, as well as druggability assessment. It has also developed multiple proprietary technology platforms, including LeadsBody (a CD3 T-cell engager platform), X-body (a 4-1BB engager platform), TOPiKinectics (an ADC platform) and ImBiTDC (a TDC platform), which serve as the cornerstone for its continued innovation and have been validated by the clinical outcomes of its bispecific antibody portfolios.
Leads Biolabs has established integrated capabilities across early discovery, translational medicine, clinical development, CMC and business development. The innovative nature and competitive strengths of its drug candidates, coupled with its global perspectives, proactive strategy, and efficient clinical validation, have made it an attractive partner for leading industry players and investment institutions. For more information, please visit https://en.leadsbiolabs.com/
Contact: yizi@leadsbiolabs.com
Legal Disclaimer:
EIN Presswire provides this news content "as is" without warranty of any kind. We do not accept any responsibility or liability for the accuracy, content, images, videos, licenses, completeness, legality, or reliability of the information contained in this article. If you have any complaints or copyright issues related to this article, kindly contact the author above.
