Phase 3 Study of Cadonilimab and Chemotherapy vs. Chemotherapy with or without Nivolumab for First-Line Treatment of HER2-negative Advanced Gastric/GEJ Cancer

Inclusion Criteria

• Able to understand and agree to the study requirements and provide written consent.
• Diagnosed with advanced gastric or gastroesophageal junction cancer that cannot be surgically removed or has spread.
• No previous treatment for advanced gastric or gastroesophageal junction cancer, unless it was part of a treatment plan aimed at curing the cancer and at least 6 months have passed since the last treatment.
• In good general health with a performance status score of 0 or 1.
• At least 18 years old.
• Have test results showing PD-L1 expression.
• Have at least one tumor that can be measured by scans, even if it was previously treated with radiation.
• Have good organ function based on recent lab tests.
• Expected to live at least 3 more months.
• Women who can become pregnant must have a negative pregnancy test and agree to use birth control during and after treatment for a specified time.
• Men must agree to use birth control during and after treatment for a specified time.

Exclusion Criteria

• Have a different type of cancer, such as squamous cell carcinoma or sarcoma.
• Have HER2-positive cancer.
• Have active cancer that has spread to the brain or spinal cord, unless previously treated and stable.
• Have fluid buildup around the lungs, heart, or abdomen that needs frequent drainage.
• Have significant bleeding issues recently.
• Have a history of serious gastrointestinal problems within the last 6 months.
• Have symptoms suggesting the cancer is worsening significantly.