Strategic Layout Accelerates: LBL-024 Dosed First Patient in Phase Ib/ⅡClinical Trial for Platinum-Resistant Ovarian Cancer
Nanjing, China – December 23, 2025 – Nanjing Leads Biolabs Co., Ltd. (“Leads Biolabs” or the “Company,” Stock Code: 9887.HK) today announced that the first patient has been successfully dosed in a Phase Ⅰb/Ⅱ clinical study evaluating Opamtistomig (LBL-024), a PD-L1/4-1BB bispecific antibody, for the platinum-resistant ovarian cancer.

Opamtistomig is a uniquely engineered bispecific antibody that simultaneously blocks PD-1/L1-mediated immune suppression and enhances 4-1BB-dependent T-cell activation. By restoring T-cell functionality and expanding effector T-cell populations, Opamtistomig has the potential to offer superior anti-tumor efficacy compared to PD-1/PD-L1, thereby improving response rates in hard-to-treat cancers such as platinum-resistant ovarian cancer.
The open-label, multi-center Phase Ib/II clinical study is led by Professor Lingying Wu of Cancer Hospital, Chinese Academy of Medical Sciences and is being conducted across multiple hospitals in China. The trial aims to evaluate the efficacy and safety of Opamtistomig in combination with paclitaxel for the treatment of patients with platinum-resistant ovarian cancer.
Executive Commentary
Dr. Charles Cai, Chief Medical Officer of Leads Biolabs, commented:
“Expanding Opamtistomig’s indications to platinum-resistant ovarian cancer marks a pivotal step forward. Patients with this aggressive disease currently face limited options and poor outcomes, underscoring the urgent need for innovative therapies. Opamtistomig, with its dual-targeting mechanism, has demonstrated promising efficacy and safety in clinical trials across multiple cancers, including extrapulmonary neuroendocrine carcinoma, small cell lung cancer, biliary tract cancer and non-small cell lung cancer. We hope this drug could offer a transformative treatment for this challenging patient population.”
About Opamtistomig (LBL-024)
Opamtistomig (LBL-024) is a potential first-in-class bispecific antibody that simultaneously targets PD-L1 and the co-stimulatory receptor 4-1BB. It is the first 4-1BB–targeting bispecific antibody globally to advance to a single-arm pivotal trial as monotherapy, and it holds promise to become the first approved therapy specifically for extrapulmonary neuroendocrine carcinoma (EP-NEC)—a rare malignancy with substantial unmet clinical need.
Developed using Leads Biolabs’ proprietary X-Body bispecific platform, Opamtistomig features a 2:2 molecular format, incorporating two binding domains each for PD-L1 and 4-1BB with an optimized affinity ratio. This unique design enables dual functionality: reversing PD-L1–mediated immune suppression while selectively enhancing T-cell activation, resulting in a potent and synergistic anti-tumor immune response.
In two ongoing clinical studies in China, Opamtistomig has demonstrated promising efficacy and a favorable safety profile in patients with advanced EP-NEC, both as monotherapy and in combination with chemotherapy. Given the absence of a globally accepted standard of care for EP-NEC, these results support the advancement of a single-arm pivotal study toward potential accelerated approval.
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.
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. Beyond EP-NEC, Opamtistomig has received clinical trial approvals across multiple tumor types with high unmet medical needs, including small cell lung cancer (SCLC), biliary tract cancer (BTC), ovarian cancer (OC), non-small cell lung cancer (NSCLC), esophageal squamous cell carcinoma (ESCC), hepatocellular carcinoma (HCC), gastric cancer (GC), triple-negative breast cancer (TNBC), and malignant melanoma. Encouraging clinical activity has already been observed in SCLC, BTC, OC, and other indications, underscoring Opamtistomig’s potential as a broad-spectrum immuno-oncology therapy.
About Ovarian Cancer
In 2020, there were 9.2 million newly diagnosed cancer cases among women worldwide, with ovarian cancer accounting for 3.4%. There were 4.4 million cancer related deaths among women, with ovarian cancer contributing 4.7%. Ovarian cancer ranked 8th and 9th in incidence and mortality among female malignancies, respectively. Due to its insidious onset and lack of effective screening or early diagnostic methods, most patients are diagnosed at an advanced stage, resulting in a poor prognosis, with a 5-year survival rate of less than 45%.
Platinum-based drugs are among the most effective chemotherapeutic agents for ovarian cancer, achieving an initial response rate of up to 80%. However, platinum resistance is common, and 70% of ovarian cancers relapse and eventually become platinum-resistant ovarian cancer (PROC). The standard treatment for PROC is sequential non-platinum single-agent chemotherapy, but the objective response rate (ORR) is low (≤15%), and progression-free survival (PFS) and overall survival (OS) are short (median PFS ~3-4 months, OS ~12 months). Therefore, there is an urgent need for new, more effective strategies to improve clinical outcomes for ovarian cancer patients.
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.
We are a front-runner in next-generation immuno-oncology treatments with a differentiated pipeline of 14 innovative drug candidates, including six clinical-stage drug candidates, of which four lead products are among the top-tier clinically advanced candidates globally.
We adopt a science-driven R&D approach and have successfully established comprehensive R&D capabilities spanning antibody discovery and engineering, in vivo and in vitro efficacy evaluation, as well as druggability assessment. We have also developed multiple proprietary technology platforms, including LeadsBody platform (a CD3 T-cell engager platform), X-body platform (a 4-1BB engager platform), TOPiKinectics (ADC platform), which serve as the cornerstone for our continued innovation and have been validated by the clinical outcomes of our bispecific antibody portfolios.
We have established integrated capabilities across early discovery, translational medicine, clinical development, CMC and business development. The innovative nature and competitive strengths of our drug candidates, coupled with our global perspectives, proactive strategy, and efficient clinical validation, have made us an attractive partner for leading industry players and investment institutions.
For more information, please visit https://en.leadsbiolabs.com/
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Company Name: Leads Biolabs
Contact Person: Yizi
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Country: China
Website: https://www.leadsbiolabs.com/


