A Study on the Safety and Efficacy of the Combination of Candenizumab, Lenvatinib, and SOX Regimen in the Treatment of HER2 Negative Advanced Gastric or Gastroesophageal Junction Adenocarcinoma Patients

This study is testing a new combination of treatments — an immunotherapy drug (candenizumab), a targeted therapy (lenvatinib), and a chemotherapy regimen (SOX) — as a first-line treatment for people with advanced HER2-negative stomach or gastroesophageal junction cancer that cannot be surgically removed. **You may be eligible if...** - You are between 18 and 75 years old - You have advanced or metastatic HER2-negative stomach or junction cancer confirmed by biopsy - You have not previously received chemotherapy, targeted therapy, or immunotherapy for your advanced disease - You have measurable tumors on imaging - Your general health is good (ECOG 0-1) with expected survival over 3 months - Your blood counts, liver, and kidney function are within acceptable ranges **You may NOT be eligible if...** - You have received recent treatment for advanced disease (prior adjuvant therapy is allowed if it ended at least 6 months ago) - You are pregnant or breastfeeding - Your organ function does not meet minimum thresholds Talk to your doctor to see if this trial is right for you.