Lenvatinib Plus Tislelizumab and CapeOX as First-Line Treatment for Advanced GC/GEJC With Positive PD-L1 and Low TMEscore

Inclusion criteria

• Patients voluntarily participated in the study, signed the informed consent, and had good compliance;
• Age over 18 (including 18 years old), gender is not limited;
• Histologically and/or cytologically confirmed advanced gastric cancer or gastroesophageal junction adenocarcinoma (stage IV);
• Tumor with PD-L1 positive and low tumor microenvironment score (TMEscore)
• Have not received systemic antitumor therapy before; Or have previously received adjuvant or neoadjuvant therapy (chemotherapy/radiotherapy) for the purpose of cure, and the time of tumor recurrence > 6 months since the last treatment
• ECOG performance status of 0-2 points;
• Expected survival ≥12 weeks;
• Blood test (without blood transfusion within 14 days) 1) Neutrophil absolute value ≥1.5×10^9/L, platelet ≥100×10^9/L, hemoglobin ≥90g/L); 2) Liver function test (aspartate aminotransferase and glutamate aminotransferase ≤3×ULN, bilirubin ≤1.5×ULN; In case of liver metastasis, AST and ALT≤5×ULN); 3) Renal function (serum creatinine ≤1.5×ULN, or creatinine clearance (CCr)≥60ml/min);
• Men and women of childbearing age must use effective contraceptive methods.

Exclusion criteria

• Previously received therapy that targets T cell co-stimulation or checkpoint pathways ,such as anti-PD-1 antibodies, anti-PD-L1 antibodies, anti-CTLA-4 antibodies, etc.;
• Previously received anti-vascular small-molecule targeted drug therapy, such as fuquinitinib, regofenib, etc.;
• Received major surgery within 4 weeks prior to the first drug administration; radiotherapy, radiofrequency ablation and other investigational drugs for tumors within 2 weeks;
• Received live vaccine within 4 weeks prior to the first drug administration (except inactivated viral vaccine for seasonal influenza);
• A history of severe intolerance to drugs involved in the study (i.e., grade 4 toxicity of one of these drugs; Class 3-4 toxicity of other co-administered drugs is not excluded);
• Known allergy to the study drug or any of its excipients;
• HER2 positive gastric cancer or gastroesophageal junction adenocarcinoma;
• The patient had other malignancies within the previous 5 years or at the same time (except cured basal cell carcinoma, stage I squamous cell carcinoma, in situ carcinoma, intramucosal carcinoma, and superficial bladder cancer);
• Known brain or meningeal metastases;
• Patients who are preparing for or have previously received an organ or bone marrow transplant;
• A history of human immunodeficiency virus (HIV) infection;
• A history of psychotropic substance abuse or drug use;
• Condition that may interfere with the detection and management of suspected drug-related pulmonary toxicity, such as interstitial pneumonia, pneumoconiosis, radiation pneumonia, drug-related pneumonia, or severe impairment of lung function;
• Known active or suspected autoimmune disease (except for patients with stable disease at enrollment who do not require systemic immunosuppressive therapy);
• Patients who required systemic corticosteroids (> 10 mg/ day efficacy dose of prednisone) or other immunosuppressive agents within 2 weeks prior to initial administration or during the study period. However, adrenal hormone replacement therapy with topical or inhaled steroids, or a therapeutic dose of prednisone ≤ 10mg/ day in the absence of active autoimmune disease was permitted;
• Any active infection that requires systematic anti-infective treatment occurs within 2 weeks prior to the first dose (expect prophylactic antibiotic therapy, such as for urinary tract infections or chronic obstructive pulmonary disease);
• Active heart disease, including myocardial infarction, severe/unstable angina in the 6 months prior to treatment. Echocardiography showed that the left ventricular ejection fraction was less than 50%, indicating poor arrhythmia control.
• Obvious clinical bleeding symptoms or obvious bleeding tendency and hemoptysis within 3 months prior to treatment. Or treatment of venous/venous thrombosis events within the preceding 6 months, such as cerebrovascular accidents (including transient ischemic attack, cerebral hemorrhage, cerebral infarction), deep vein thrombosis and pulmonary embolism; Long-term anticoagulant therapy with warfarin or heparin, or long-term antiplatelet therapy (aspirin ≥300 mg/day or clopidogrel ≥75 mg/day) is required;
• Any other disease, a clinically significant metabolic abnormality, abnormal physical examination or abnormal laboratory examination, for which, in the investigator's judgment, there is reason to suspect that the patient has a disease or condition unsuitable for the use of the investigational agent;
• Anything that, in the investigator's opinion, could put subjects receiving the study drug at risk, interfere with the study drug, subject safety assessment, or interpretation of the results;
• Pregnant or lactating women or women who may become pregnant.