Nanjing Leads Biolabs Co., Ltd. (Leads Biolabs) reported that its self-developed bispecific antibody LBL-024 (Opamtistomig) has completed the safety lead-in portion of a Phase II study in first-line treatment for locally advanced or metastatic esophageal squamous cell carcinoma (ESCC) and has progressed to the expansion stage.

The safety lead-in phase combined LBL-024 with chemotherapy and delivered “encouraging efficacy signals” alongside a “favorable safety and tolerability profile,” according to trial investigators led by Professor Shen Lin of Peking University Cancer Hospital. Based on these data, the study will now transition to a randomized, controlled expansion stage that will compare LBL-024 plus chemotherapy directly against tislelizumab plus chemotherapy, the current standard-of-care regimen for first-line ESCC.

Clinical pipeline snapshot • LBL-024 is under evaluation in 11 active studies: one pivotal single-arm registrational trial, one confirmatory Phase III trial, and nine proof-of-concept (POC) studies. • Enrollment has concluded in POC trials for first-line extrapulmonary neuroendocrine carcinoma (EP-NEC), small cell lung cancer (SCLC) and biliary tract cancer (BTC); the EP-NEC program has progressed to a confirmatory Phase III stage. • POC studies in hepatocellular carcinoma (HCC) and ESCC have now moved to expansion phases. • Roughly 800 patients have received LBL-024 across trials, with consistent reports of acceptable safety and tolerability.

Drug profile and regulatory milestones • LBL-024 is a PD-L1/4-1BB bispecific antibody developed on Leads Biolabs’ proprietary X-body® platform, designed for conditional 4-1BB activation while relieving PD-1/PD-L1-mediated immunosuppression. • The molecule has potential first- or best-in-class positioning in multiple solid tumor types, including non-small cell lung cancer, SCLC, EP-NEC and BTC. • Regulatory designations to date: Breakthrough Therapy (NMPA, Oct 2024), U.S. FDA Orphan Drug (Nov 2024) and Fast Track (Jan 2026), and EU Orphan Drug (Jan 2026).

ESCC market context China accounts for roughly half of global esophageal cancer cases. IARC 2022 data cite 224,000 new cases and 187,000 deaths annually, with median overall survival of 12–17 months under current immunochemotherapy regimens and a five-year survival rate of 10–30 %. The advancement of LBL-024 seeks to address this significant unmet clinical need.

Leads Biolabs underscores that development risks remain and successful commercialization of LBL-024 is not guaranteed.