NANJING, China | July 10, 2026
Nanjing Leads Biolabs Co., Ltd. has announced that the Center for Drug Evaluation (CDE) of China’s National Medical Products Administration (NMPA) has granted Priority Review to the Biologics License Application (BLA) for Opamtistomig (LBL-024), the company’s investigational PD-L1/4-1BB bispecific antibody, for the treatment of advanced extrapulmonary neuroendocrine carcinoma (EP-NEC). The regulatory milestone significantly accelerates the review timeline from the standard 200 working days to approximately 130 working days, bringing the therapy one step closer to commercialization. The BLA is supported by positive results from a pivotal registrational clinical study evaluating Opamtistomig monotherapy in patients with advanced EP-NEC whose disease had progressed following two or more prior lines of systemic therapy. The inclusion in China’s priority review pathway underscores the urgent need for effective treatments in this aggressive cancer while reinforcing Leads Biolabs’ leadership in next-generation immuno-oncology and bispecific antibody development.
Priority Review Accelerates Commercialization of Novel Immunotherapy
The Priority Review designation represents a major regulatory milestone for Opamtistomig, providing greater certainty regarding the anticipated approval timeline while enabling Leads Biolabs to advance commercial launch preparations. Developed using the company’s proprietary X-Body bispecific antibody platform, Opamtistomig simultaneously targets PD-L1 and the co-stimulatory receptor 4-1BB, combining immune checkpoint inhibition with conditional T-cell activation to generate a stronger anti-tumor immune response. This differentiated dual mechanism is designed to overcome resistance commonly observed with traditional PD-1/PD-L1 inhibitors, particularly in immune-cold tumors such as EP-NEC. Company leadership noted that the therapy has already demonstrated encouraging survival benefits and clinical activity across multiple solid tumors, supporting its potential as a next-generation backbone immunotherapy for several difficult-to-treat cancers beyond neuroendocrine carcinoma.
Clinical Development Demonstrates Broad Oncology Potential
Opamtistomig (LBL-024) has rapidly emerged as one of the most advanced 4-1BB-targeting bispecific antibodies in global clinical development. The investigational therapy has already demonstrated first- or best-in-class potential across Phase II and registrational clinical trials involving multiple cancer indications, including non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), biliary tract cancer (BTC), ovarian cancer, hepatocellular carcinoma, gastric cancer, esophageal squamous cell carcinoma, triple-negative breast cancer, malignant melanoma, and EP-NEC. As the first 4-1BB-targeting bispecific antibody worldwide to advance into a single-arm pivotal monotherapy trial, the candidate has now been evaluated across 13 solid tumor indications, reflecting the broad therapeutic potential of its unique mechanism of action.
Advertisement
The therapy has also received multiple regulatory recognitions, including Breakthrough Therapy Designation (BTD) from China’s NMPA, Orphan Drug Designation (ODD) from the U.S. Food and Drug Administration (FDA) and the European Commission, as well as FDA Fast Track Designation (FTD) for EP-NEC, highlighting its potential to address significant unmet medical needs globally.
Addressing an Urgent Need for Advanced EP-NEC Patients
Extrapulmonary neuroendocrine carcinoma (EP-NEC) is an aggressive and highly lethal immune-cold cancer with no approved therapy currently available anywhere in the world. Although platinum-based chemotherapy remains the standard first-line treatment, patients typically experience a median overall survival of approximately one year, while those progressing after multiple treatment lines have extremely limited therapeutic options and poor clinical outcomes. Available later-line therapies generally achieve objective response rates between 0% and 10%, with median overall survival of only three to four months, emphasizing the urgent need for innovative treatment strategies.
Through the development of Opamtistomig, Leads Biolabs aims to redefine immunotherapy for difficult-to-treat solid tumors by combining advanced bispecific antibody engineering, precision immuno-oncology, and a robust clinical development strategy. The Priority Review milestone not only accelerates the potential availability of this innovative therapy for patients with EP-NEC, but also reinforces Leads Biolabs’ commitment to expanding access to next-generation immunotherapies capable of transforming treatment outcomes across multiple high-unmet-need cancers.
Source: Leads Biolabs press release
