This study primarily evaluates the efficacy and safety of the LM-302 plus tislelizumab regimen versus tislelizumab plus chemotherapy in the treatment of previously untreated locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma patients with CLDN18.2 positivity.
Willing and able to comply with the study's visit schedule, treatment plan, laboratory tests, and other research procedures.
Age ≥ 18 years.
Histologically or cytologically confirmed adenocarcinoma of the stomach or gastroesophageal junction.
Patients who have previously received radical neoadjuvant chemotherapy or adjuvant chemotherapy (radiotherapy) based on a platinum-based combination chemotherapy regimen and have not developed distant metastasis or local recurrence within 6 months after completion of treatment can be included.
Other pathological types confirmed by histopathology, such as squamous cell carcinoma, sarcoma, or undifferentiated carcinoma.
There are gastric cancer lesions confirmed by imaging that are accompanied by cavities or necrosis, and are closely related to major blood vessels, and are assessed by the researchers as posing a high risk of major bleeding.
Patients with known central nervous system (CNS) metastases. Patients with non-meningeal, midbrain, pontine, or spinal cord metastases who are judged by the investigator to have stable brain metastases can be enrolled. Stable brain metastases are defined as patients whose brain metastases have undergone treatment and the condition of the metastases has stabilized (brain imaging examination at least 28 days before randomization shows stable lesions, no neurological symptoms, and no immediate need for local or systemic treatment within 14 days before randomization), with no evidence of new or previously existing brain metastases enlarging.
Clinically uncontrollable third-space effusion, such as moderate or greater volume, requiring long-term catheterization, previous history of intestinal obstruction or paralysis, compartmented ascites, undergoing or planning to undergo local treatment (including drainage, peritoneal shunt, or cell-free concentrated ascites reinfusion therapy) within 14 days prior to screening, or significant increase within 2 weeks after local treatment, meeting any of the above criteria or deemed unsuitable for enrollment by the investigator.