NANJING, China, August 3, 2026
Leads Biolabs announced that the Center for Drug Evaluation (CDE) of China’s National Medical Products Administration (NMPA) has approved the Investigational New Drug (IND) application for a Phase Ib/II multicenter clinical trial evaluating its proprietary PD-L1/4-1BB bispecific antibody, Opamtistomig (LBL-024), in combination therapy for metastatic colorectal cancer (mCRC). The open-label study will assess the safety, efficacy, and potential predictive biomarkers of Opamtistomig-based combination regimens in patients with metastatic colorectal cancer. The approval expands the company’s immuno-oncology development strategy into colorectal cancer, strengthening its gastrointestinal oncology pipeline alongside ongoing programs in biliary tract cancer, gastric cancer, and esophageal squamous cell carcinoma. The milestone reflects Leads Biolabs’ continued effort to develop next-generation immunotherapies for cancers with significant unmet medical needs.
Phase Ib/II Trial Targets High-Unmet-Need MSS/pMMR Colorectal Cancer
Metastatic colorectal cancer (mCRC) remains one of the most difficult gastrointestinal malignancies to treat, with a five-year survival rate below 13%. While immune checkpoint inhibitors have demonstrated significant clinical benefit in patients with microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR) tumors, these subtypes represent only about 5% of mCRC cases. The remaining 95% of patients have microsatellite stable (MSS) or mismatch repair proficient (pMMR) tumors that typically respond poorly to conventional immunotherapy, leaving chemotherapy combined with targeted therapy as the current standard treatment. The newly approved clinical study will investigate whether Opamtistomig can improve treatment outcomes in this large patient population by overcoming resistance to existing immunotherapy approaches through combination treatment strategies.
Dual-Target Immunotherapy Aims to Restore Anti-Tumor Immunity
Opamtistomig (LBL-024) is a bispecific antibody designed to simultaneously block the PD-L1 immune checkpoint pathway while conditionally activating the 4-1BB co-stimulatory receptor, creating a dual mechanism intended to restore immune responses against cancer cells. By reducing tumor-induced immune suppression and promoting T-cell activation, proliferation, and long-term immune memory, the therapy seeks to enhance anti-tumor activity, particularly in immunologically “cold” tumors such as MSS/pMMR colorectal cancer. According to Leads Biolabs, the mechanism has already demonstrated encouraging preliminary activity across multiple tumor types, including biliary tract cancer, non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), and extrapulmonary neuroendocrine carcinoma (EP-NEC). The company believes expanding clinical evaluation into colorectal cancer further supports Opamtistomig’s potential as a next-generation pan-tumor immuno-oncology platform.
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IND Approval Expands Leads Biolabs’ Gastrointestinal Oncology Pipeline
The NMPA IND approval marks an important milestone for Leads Biolabs as it broadens the clinical development of Opamtistomig across gastrointestinal cancers while addressing one of the largest unmet needs in immuno-oncology. By targeting patients with MSS/pMMR metastatic colorectal cancer, who currently have limited treatment options, the Phase Ib/II program has the potential to expand the role of bispecific antibody therapies in solid tumors. If successful, the study could strengthen the company’s gastrointestinal oncology franchise while supporting broader development of PD-L1/4-1BB dual-target immunotherapy for multiple difficult-to-treat cancers, reinforcing the growing role of innovative bispecific antibodies in precision cancer treatment.
Source: Leads Biolabs, press release
