Exploratory Clinical Trial on the Safety, Efficacy, and Pharmacokinetics of XKDCT086 (iPD-1-Claudin18.2-CAR-T) in Claudin 18.2 Positive Advanced Solid Malignant Tumors: a Single Center, Single Arm, Dose-increasing Trial

Inclusion Criteria: * 1\. Age range from 18 to 75 years old (including threshold), regardless of gender; 2\. Patients with advanced solid malignant tumors with positive expression of Claudin 18.2 (including but not limited to gastric cancer, esophageal gastric junction adenocarcinoma, and esophageal adenocarcinoma); And after sufficient treatment, the condition cannot be completely relieved or continue to progress;; 3\. At least one measurable lesion (non lymph node lesion with a length diameter of ≥ 10mm and lymph node lesion with a short diameter of ≥ 15mm) using the RECIST 1.1 standard; 4\. Expected survival time ≥ 12 weeks; 5\. ECOG score 0-1 points; 6\. The laboratory test values conducted for screening must meet the following standards: Blood routine examination: WBC ≥ 3.0 × 10\^9/L ANC ≥ 1.5 × 10\^9/L HB ≥ 80g/L (no blood transfusion received within 2 weeks) PLT ≥ 100 × 10\^9/L Blood biochemical examination: ALT and AST ≤ 2.5 × ULN (≤ 5 if accompanied by liver metastasis) × ULN ALB ≥ 30g/L Serum creatinine ≤ 1.5 × ULN or GFR\>50mL/min (GFR=\[(140 age) × weight × (0.85 female)\]/(72 × Scr) TBIL ≤ 1.5 × ULN Coagulation function test: APTT ≤ 1.5ULN, while INR or PT ≤ 1.5ULN (without receiving anticoagulant therapy) 7\. Women of childbearing age must undergo serum pregnancy tests during screening and before receiving clearance treatment, and the results must be negative; 8\. If the patient uses the following drugs, the corresponding situation …