NANJING, China, July 30, 2026 (GLOBE NEWSWIRE) -- Nanjing Leads Biolabs Co., Ltd. ("Leads Biolabs" or the "Company," Stock Code: 9887.HK) announced that the Phase II clinical study of its core product Opamtistomig (LBL-024, a PD-L1/4-1BB bispecific antibody) for the treatment of first-line advanced biliary tract cancer (BTC) has completed enrollment of all 70 patients. In April 2026, the study successfully entered the expansion phase based on a favorable safety profile and robust efficacy that exceeded expectations, and rapidly completed full patient enrollment, fully demonstrating the efficient clinical advancement and continuously validated significant efficacy of Opamtistomig.
Despite the recent adoption of PD-(L)1 immunotherapy combined with chemotherapy as a first-line standard of care for advanced BTC, clinical benefits remain limited. Current standard regimens, including pembrolizumab plus chemotherapy and durvalumab plus chemotherapy, have demonstrated objective response rates (ORR) below 30% and median overall survival (OS) of only approximately 12-13 months, leaving a substantial unmet medical need in this aggressive malignancy.
The potential of Opamtistomig as an IO 2.0 pan-tumor cornerstone therapy has been continuously validated across three dimensions: broad-spectrum anti-tumor activity, long-term survival benefit trends, and a safety profile comparable to PD-(L)1 monoclonal antibodies. Existing data show that, following extrapulmonary neuroendocrine carcinoma (EP-NEC) and small cell lung cancer (SCLC), Opamtistomig has once again demonstrated highly competitive efficacy in BTC, a typical immune-cold tumor, with the potential to elevate the efficacy of immunotherapy in BTC to new heights. Given that the predominant pathological type of BTC is adenocarcinoma, combined with the positive data previously observed in squamous cell carcinoma subtypes of major cancer types such as non-small cell lung cancer (NSCLC), Opamtistomig has shown clear efficacy in both adenocarcinoma and squamous cell carcinoma types, with its broad-spectrum anti-cancer potential being continuously validated.
The multicenter study is led by Academician Zhou Jian of Zhongshan Hospital, Fudan University and is being conducted across multiple hospitals in China. Results from safety run-in data showed that Opamtistomig in combination with chemotherapy demonstrated a favorable overall safety profile and good tolerability, with no new safety signals identified. Preliminary efficacy assessments showed an encouraging tumor shrinkage. Detailed clinical data will be presented at the European Society for Medical Oncology (ESMO) Annual Meeting to be held in Madrid, Spain from October 23 to 27, 2026.
Executive Commentary
Dr. Charles Cai, Chief Medical Officer of Leads Biolabs, said: "The rapid progress of our Phase II BTC study reflects the strong confidence investigators and patients have placed in the encouraging efficacy signals generated by Opamtistomig to date. Immune-cold tumors remain among the greatest challenges in oncology and represent one of the most important frontiers for next generation immunotherapy. Across multiple immune-cold tumor types, Opamtistomig has consistently demonstrated promising clinical activity, further validating its potential as an IO 2.0 pan-tumor cornerstone therapy. We are committed to accelerating the clinical development of Opamtistomig in BTC and look forward to bringing a more effective and durable treatment option to patients with this devastating disease as early as possible."
About Biliary Tract Cancer
Biliary tract malignancies primarily include gallbladder cancer and intrahepatic/extrahepatic cholangiocarcinoma, with approximately 419,100 new cases globally in 2024. These malignancies are predominantly ?adenocarcinomas? with high invasiveness, and most cases are diagnosed at advanced stages, leading to ?poor prognosis? (5-year survival rate <5%)?. Currently, global incidence of biliary tract malignancies is rising, with the highest prevalence observed in Asian countries.
Although ?PD-1/L1 inhibitors combined with chemotherapy? have been approved as first-line treatment for advanced biliary tract malignancies, clinical benefits remain limited: ?Modest improvement in median overall survival (OS)? (from ~11.5 to 12.8 months)? and ?Low objective response rate (ORR)? (<30%)?. These gaps highlight ?unmet medical needs? for more effective therapies?.
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/
