Nanjing Leads Biolabs Co., Ltd. ("Leads Biolabs" or the "Company," Stock Code: 9887.HK) today announced the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA) has accepted the New Drug Application (NDA) for Opamtistomig (LBL-024), the Company's proprietary PD-L1/4-1BB bispecific antibody, as a monotherapy for the treatment of previously treated advanced extrapulmonary neuroendocrine carcinoma (EP-NEC).

Opamtistomig is the first PD-L1/4-1BB bispecific antibody globally to enter NDA review and was granted Priority Review by the CDE on July 10, 2026. If approved, Opamtistomig would become the world's first approved antibody drug directly targeting 4-1BB, as well as the first approved agonistic antibody. This milestone would also make 4-1BB the fourth immuno-oncology target worldwide with an approved therapy, following PD-1/PD-L1, CTLA-4 and LAG-3.

The NDA is supported by positive results from a registrational clinical study led by Professor Shen Lin of Peking University Cancer Hospital and conducted across 34 clinical sites. The study completed enrollment of 96 patients with EP-NEC in August 2025. Detailed results are planned for presentation at a leading international medical congress.

Dr. Charles Cai, Chief Medical Officer of Leads Biolabs, said: "The acceptance of Opamtistomig's NDA marks a major milestone in our mission to develop differentiated immunotherapies for patients with high unmet medical needs. Opamtistomig has received multiple regulatory designations that have accelerated its development, including Breakthrough Therapy Designation and Priority Review from China's CDE, Orphan Drug Designation and Fast Track designation from the U.S. FDA, and Orphan Drug Designation from the European Medicines Agency.

As the first 4-1BB-targeting bispecific antibody globally to advance into registrational clinical development, Opamtistomig represents a significant breakthrough in the treatment of EP-NEC, a highly aggressive, immunologically 'cold' tumor for which there are currently no approved therapies worldwide. Beyond EP-NEC, we are advancing our clinical program across multiple high-burden indications, including non‑small cell lung cancer, biliary tract cancer, hepatocellular carcinoma, esophageal squamous cell carcinoma, and ovarian cancer. Clinical data generated from seven indications have shown promising antitumor activities and support the broad therapeutic potential of Opamtistomig.

We believe Opamtistomig has the potential to become a cornerstone of next-generation immunotherapy and to establish a new paradigm for T-cell agonist development. The NDA acceptance represents an important validation of our differentiated approach and brings us one step closer to delivering a novel treatment option to patients with limited therapeutic alternatives."

Dr. Xiaoqiang Kang, Founder, Chairman, and CEO of Leads Biolabs, added: "The acceptance of Opamtistomig's NDA marks a critical step forward as Leads Biolabs transitions toward commercialization. Since our founding, we have deliberately moved beyond the highly competitive PD-1/PD-L1 space to pursue differentiated mechanisms and address areas of significant unmet medical needs, with 4-1BB representing one of the most promising frontiers in immuno-oncology.

Today, Opamtistomig stands poised to become the world's first approved 4-1BB-targeting drug. This achievement reflects our 14-year commitment to differentiated innovation and our determination to tackle some of the most challenging targets in oncology.

We are grateful to the patients, investigators, clinical research teams, regulatory authorities, and all our employees and partners who have contributed to the development of Opamtistomig. We will work closely with regulatory authorities throughout the review process to bring Opamtistomig to patients as quickly as possible."