Nanjing Leads Biolabs Co., Ltd. announced that its Phase II clinical study evaluating Opamtistomig (LBL-024), a proprietary PD-L1/4-1BB bispecific antibody, in combination with bevacizumab for the treatment of first-line hepatocellular carcinoma (HCC) has successfully completed the safety run-in phase assessment following expert review and has advanced into the expansion phase. The study is led by Professor Zhou Jian, President of Zhongshan Hospital, Fudan University, and Academician of the Chinese Academy of Sciences.

Preliminary clinical data demonstrated that Opamtistomig in combination with bevacizumab has shown encouraging anti-tumor activity and a favorable safety profile in patients with HCC, supporting further clinical evaluation in the expansion phase.

HCC represents a significant global health burden and is the fourth most common malignant tumor and the second leading cause of cancer-related mortality in China, with approximately 368,000 new cases and 317,000 deaths recorded annually. Due to its often insidious onset, fewer than 30% of patients are eligible for potentially curative treatment at diagnosis, making systemic anti-tumor therapies essential for patients with intermediate-to-advanced disease.

Currently, PD-1/PD-L1 inhibitors in combination with bevacizumab have become one of the first-line standard treatments for advanced HCC both in China and globally; however, median overall survival is only approximately 19 to 20 months, median progression-free survival is less than 7 months, and the objective response rate does not exceed 30%. These limitations highlight the urgent need for more effective and durable treatment strategies.

Opamtistomig has demonstrated promising efficacy signals and broad therapeutic potential across multiple tumor types, including extrapulmonary neuroendocrine carcinoma (EP-NEC), non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC) and biliary tract cancer (BTC). Powered by the proprietary X-body™ platform, which enables tumor-localized activation of 4-1BB signaling, Opamtistomig has maintained a favorable safety profile across nearly 800 treated patients, further supporting its potential as a next-generation IO 2.0 pan-tumor immunotherapy platform. The encouraging clinical findings in HCC further strengthen the clinical validation of Opamtistomig’s differentiated mechanism and therapeutic potential.

Executive Commentary
Dr. Charles Cai, Chief Medical Officer of Leads Biolabs, said: “Advancing this Phase II study of Opamtistomig in first-line HCC into expansion phase is an important milestone in validating its potential as a pan-tumor immunotherapy. While PD-1/PD-L1-based combination therapies have become the standard of care for first-line HCC, significant unmet medical needs remain. The encouraging efficacy signals observed with Opamtistomig in combination with bevacizumab provide further confidence in its potential to improve treatment outcomes for patients with HCC. We will continue to accelerate clinical development and global registration efforts to bring this innovative therapy to patients worldwide as quickly as possible.”