This trial is a Phase II study. All patients are resectable Gastric or Gastroesophageal Junction Adenocarcinoma, Eastern Cooperative Oncology Group (ECOG) performance status 0-1.The purpose of this study is to evaluate the efficacy and safety of cadonilimab combined with chemotherapy with or without AK117 neoadjuvantin treatment of resectable Gastric or Gastroesophageal Junction Adenocarcinoma.

Inclusion Criteria:

• Be able and willing to provide written informed consent.
• 18 to 75 years old.
• Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Has a histologically confirmed diagnosis of Gastric or Gastroesophageal Junction Adenocarcinoma(G/GEJ).
• Has Stage T3-4N+M0 G/GEJ (American Joint Committee on Cancer [AJCC])
• Has measurable disease based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1.
• Has adequate organ function.

Exclusion Criteria:

• Are there suspected metastases or locally advanced, unresectable disease, regardless of disease stage.
• Is currently participating in a study of an investigational agent or using an investigational device.
• Has undergone major surgery within 30 days of Study Day 1.
• Has an active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs).
• Has known active Hepatitis B (e.g., HBsAg reactive) or Hepatitis C (e.g., HCV RNA [qualitative] is detected).
• History of myocardial infarction, unstable angina, congestive heart failure within 12 months prior to day 1 of study treatment.
• Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the study.
• Has received a live virus vaccine within 30 days of the planned first dose of study therapy.