On April 15, LaNova Medicines, a wholly-owned subsidiary of Sino Biopharmaceutical (1177.HK), announced the successful enrollment of the first patient in the Phase III registrational clinical trial of its independently developed Class 1 new drug, Tecotabart vedotin (LM-302, a CLDN18.2 ADC), combined with a PD-1 inhibitor for the first-line treatment of CLDN18.2-positive locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. This is the second Phase III clinical trial for LM-302 and the world's first Phase III clinical trial of a CLDN18.2 ADC drug without a traditional chemotherapy regimen for first-line gastric cancer. 

Aiming for First-Line Standard of Care, Covering a Broader CLDN18.2-Positive Population

Gastric cancer is a highly aggressive and heterogeneous malignant tumor. Statistics from 2025 show approximately 1.04 million new cases and 705,000 deaths from gastric cancer worldwide. Among these, China accounted for about 383,000 new cases and 277,000 deaths^[1]. 

Currently, for advanced unresectable gastric cancer, the standard first-line treatment is traditional chemotherapy combined with an immune checkpoint inhibitor (ICI). However, the median overall survival (mOS) for patients is only 14 to 20 months, which is not yet ideal^[2]. Furthermore, although a same-target monoclonal antibody (zolbetuximab) combined with chemotherapy has been recommended for patients with high CLDN18.2 expression (≥75% of tumor cells with 2+ & 3+ membrane staining intensity), its survival benefit for the broader CLDN18.2-positive population (e.g., patients with <75% tumor cell membrane staining intensity) remains unclear. There is currently a lack of head-to-head clinical studies comparing its combination with chemotherapy against the current standard of care (ICI plus chemotherapy). There is an urgent clinical need for an innovative treatment strategy that covers a broader population and offers superior efficacy. 

The newly initiated Phase III clinical trial plans to enroll patients with HER2-negative locally advanced unresectable or metastatic gastric or gastroesophageal junction (GC/GEJ) adenocarcinoma who are CLDN18.2-positive (≥25% of tumor cells with 2+ & 3+ membrane staining intensity) and have not received prior systemic therapy, at approximately 100 research centers across China. Enrolled patients will be randomly assigned to the experimental or control group in a 1:1 ratio. The primary endpoint of the study is progression-free survival (PFS) as assessed by a Blinded Independent Central Review (BICR) according to RECIST 1.1 criteria. The key secondary endpoint is overall survival (OS). This study uses an active control (i.e., the current clinical standard of care) and aims to directly demonstrate the superiority of the LM-302 combination therapy in terms of efficacy and safety. 

Impressive Phase II Clinical Data and Multi-Indication Layout Highlight Clinical Value

LM-302 is an ADC drug targeting CLDN18.2 developed by LaNova Medicines. It is composed of a recombinant humanized monoclonal antibody conjugated to the small molecule toxin monomethyl auristatin E (MMAE). It not only precisely targets CLDN18.2-positive tumor cells, but the carried small molecule toxin MMAE also has a "bystander effect," enabling it to kill surrounding tumor cells that do not express the target. More importantly, LM-302 can induce immunogenic cell death (ICD). When used in combination with a PD-1 monoclonal antibody, it can produce a significant synergistic anti-tumor effect. This powerful combination of "ADC + immunotherapy" is expected to bring deeper tumor remission for patients with CLDN18.2-positive gastric cancer. 

Prior to initiating this Phase III study, the combination of LM-302 and a PD-1 monoclonal antibody had already demonstrated significant potential for clinical benefit and good safety in a Phase II clinical study. Preliminary data showed that among 32 first-line gastric cancer patients (CLDN18.2≥25%) with at least one post-baseline efficacy evaluation, the objective response rate (ORR) was 71.9%, and the disease control rate (DCR) reached 96.9%. Notably, the combination therapy showed excellent efficacy in patients with different PD-L1 expression levels. In terms of safety, adverse events were mostly Grade 1-2, primarily hematological abnormalities, which were well-managed with clinical intervention, demonstrating overall good safety and tolerability. In terms of both efficacy and safety, the combination of LM-302 and PD-1 has the potential to become a "Best-in-class" therapy for first-line gastric cancer. 

LM-302 is currently advancing two pivotal registrational clinical trials in China. In addition to the indication for first-line combination therapy for gastric and gastroesophageal junction adenocarcinoma, the Phase III clinical study of LM-302 as a monotherapy for third-line and above CLDN18.2-positive locally advanced or metastatic gastric and gastroesophageal junction adenocarcinoma has completed enrollment of all subjects. Furthermore, multiple indications for LM-302 have been granted Breakthrough Therapy Designation by the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA), and it has received three Orphan Drug Designations (ODD) from the U.S. Food and Drug Administration (FDA), covering gastric cancer, pancreatic carcinoma, and biliary tract cancer—three cancer types with high unmet clinical needs. 

Since LaNova Medicines joined Sino Biopharmaceutical, the two parties have complemented each other's strengths, integrated resources, and collaborated efficiently. By leveraging LaNova Medicines's technological accumulation and pipeline reserves from the early R&D stage, combined with Sino Biopharmaceutical's mature clinical development capabilities and commercialization layout, the progress of multiple innovative product pipelines has been significantly accelerated, laying the foundation for innovative achievements to benefit patients sooner. 

References:

[1]https://gco.iarc.fr/tomorrow/en/dataviz/isotype?types=1&single_unit=50000&populations=900&group_populations=0&multiple_populations=0&years=2025&cancers=7

[2] CSCO Guidelines for the Diagnosis and Treatment of Gastric Cancer, 2025

Declaration:

1. This press release is intended to facilitate the communication and exchange of medical information and is for reference by healthcare professionals only. It is not for advertising purposes. 

2. The company does not recommend any drugs and/or indications. 

3. The information contained in this press release is for reference only and cannot replace professional medical guidance in any way, nor should it be considered as a diagnosis or treatment recommendation. If you wish to understand specific disease diagnosis and treatment information, please follow the advice or guidance of a physician or other healthcare professional. 

Forward-Looking Statements:

This press release contains certain forward-looking statements, including statements regarding the clinical development plans, expected clinical benefits and advantages, commercialization prospects, potential for patient clinical benefit, and potential commercial opportunities for [Tecotabart vedotin (LM-302, CLDN18.2 ADC)]. Words such as "expect", "believe", "continue", "may", "estimate", "hope", "intend", "plan", "potential", "predict", "project", "should", "will", "propose", and similar expressions are intended to identify forward-looking statements, but not all forward-looking statements contain these identifying words. These forward-looking statements are predictions or expectations made by the company based on currently available data and information, and actual results may differ materially from these forward-looking statements due to uncertainties or risks such as policy, R&D, market, and regulatory factors. Current or potential investors are advised to carefully consider the potential risks and should not place undue reliance on the forward-looking statements in this press release, which contain information only as of the date of this press release. Unless required by law, the company undertakes no obligation to update or revise any forward-looking statements in this press release as a result of new information, future events, or other circumstances.