In the field of advanced gastric cancer, CLDN18.2 is the second hot target after HER2 to have its druggability validated, with approximately 38.4% of gastric cancer patients showing high expression of CLDN18.2. On May 22, the CLDN18.2 ADC, Tecotabart Vedotin Monoclonal Antibody for Injection (LM-302), independently developed by LaNova Medicines, a core enterprise of Sino Biopharmaceutical (1177.HK), and submitted by Shanghai Chia Tai Tianqing, was officially included in the priority review and approval process. It is intended for patients with CLDN18.2-positive, locally advanced or metastatic gastric/gastroesophageal junction adenocarcinoma who have received at least two prior lines of systemic therapy. 

LM-302 is an antibody-drug conjugate (ADC) targeting CLDN18.2, independently developed by LaNova Medicines. It is composed of a recombinant humanized monoclonal antibody conjugated to the small molecule toxin MMAE. LM-302 can not only accurately identify CLDN18.2-positive tumor cells, but its MMAE payload also has a "bystander effect", which can further kill surrounding tumor cells with low or heterogeneous expression. In addition, LM-302 can induce immunogenic cell death (ICD). When combined with a PD-1 monoclonal antibody, it can produce a synergistic anti-tumor effect, providing an important mechanistic basis for "ADC + immunotherapy" combination therapy. 

As a first-in-class (FIC) drug candidate, LM-302 has shown good clinical development potential in several digestive tract tumors, including gastric cancer, pancreatic carcinoma, and biliary tract cancer. It is expected to provide a new treatment option for patients with low CLDN18.2 and low PD-L1 expression. 

Previously, LaNova Medicines announced clinical study data for LM-302 monotherapy (1.8mg/kg Q2W) in the treatment of advanced gastric cancer: among 52 evaluable patients with CLDN18.2-positive disease, the objective response rate (ORR) was 32.7%, the disease control rate (DCR) was 76.9%, the median duration of response (DOR) was 6.4 months, the median progression-free survival (PFS) was 4.9 months, and the median overall survival (OS) reached 10.9 months. The overall safety profile was manageable, and the adverse event characteristics were generally consistent with known MMAE-payload ADC products ^[1]. 

To benefit a broader patient population, LaNova Medicines will present Phase II clinical study data on LM-302 as a first-line treatment for gastric/gastroesophageal junction adenocarcinoma at the upcoming 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. The regular abstract currently available on the official website shows that among 71 patients with gastric cancer/gastroesophageal junction adenocarcinoma, the median progression-free survival (PFS) was 10.68 months in the LM-302 plus PD-1 group, and 12.55 months in the LM-302 plus PD-1 and chemotherapy group. The median OS has not been reached in either group. In patients with a lower CLDN18.2 expression threshold for positivity (≥25%), the median PFS for the two-drug combination further increased to 12.22 months. More detailed and updated data will be officially released after the poster presentation. 

Based on the positive results of this study, the world's first Phase III registrational clinical study for a "chemotherapy-free" first-line treatment for gastric cancer (LM302-03-201) was officially initiated in April 2026. It aims to explore LM-302 combined with PD-1 as an alternative to traditional chemotherapy, providing a new first-line treatment option for CLDN18.2-positive gastric cancer patients that offers a long-term treatment window, better tolerability, and a higher quality of life. 

The inclusion of LM-302 in the priority review and approval process is a key milestone for the drug, moving it from clinical research to marketing approval. If approved, Sino Biopharmaceutical will have a dual layout in the gastric cancer treatment field, with both a later-line ADC monotherapy and a first-line "ADC + immunotherapy" combination regimen. Currently, only one CLDN18.2 monoclonal antibody is approved worldwide. Sino Biopharmaceutical will accelerate the R&D process of LM-302 to provide more treatment options for CLDN18.2-positive gastric cancer patients. 

References:

[1] Chunmei Bai‍, et al.Eur J Cancer.2025 Nov 17:230:115808.

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. 

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