Nanjing Leads Biolabs Co., Ltd. (Leads Biolabs) reported that its self-developed PD-L1/4-1BB bispecific antibody, Opamtistomig (LBL-024), has completed the safety run-in of a Phase II study in first-line hepatocellular carcinoma (HCC) and has moved into the expansion phase. The trial is led by Professor Zhou Jian, President of Zhongshan Hospital, Fudan University, and an Academician of the Chinese Academy of Sciences. Preliminary findings show “clear and encouraging” efficacy signals when Opamtistomig is combined with bevacizumab, alongside a favorable safety and tolerability profile.

Market need • HCC ranks sixth globally in incidence with 0.87 million new cases and third in mortality with 0.76 million deaths in 2022, according to the World Health Organization. • China accounts for 0.37 million new HCC cases and 0.32 million deaths each year, representing 42.50% and 41.80% of the global totals. • Fewer than 30% of patients are eligible for curative treatment at diagnosis; existing PD-1/PD-L1 plus bevacizumab regimens deliver median overall survival of 19-20 months, median progression-free survival below seven months, and objective response rates under 30%, leaving a clear efficacy gap.

Drug profile and clinical footprint • Opamtistomig targets PD-L1 and conditionally activates 4-1BB through Leads Biolabs’ proprietary X-body™ platform, aiming to relieve immunosuppression while stimulating T-cell proliferation. • Safety has been evaluated in nearly 800 patients across multiple tumour types, with signals of strong efficacy in extrapulmonary neuroendocrine carcinoma (EP-NEC), non-small cell lung cancer, small cell lung cancer and biliary tract cancer. • Thirteen solid-tumour indications are under clinical evaluation, including one pivotal single-arm registrational study and eight proof-of-concept studies. • Regulatory milestones include Breakthrough Therapy Designation (CDE, China, Oct 2024), Orphan Drug Designation (FDA, Nov 2024), Fast Track Designation (FDA, Jan 2026) and Orphan Drug Designation (EU, Jan 2026) for various indications.

Next steps Advancement into the expansion phase will further test efficacy and safety in a larger first-line HCC population, reinforcing Opamtistomig’s positioning as a potential IO 2.0 “cornerstone” therapy.

Risk disclosure Leads Biolabs cautions that successful development and commercialisation of LBL-024 are not guaranteed; investors should exercise due care when dealing in the company’s shares.