In this study, 30 HER2 overexpression unresectable gastric cancer patients will enrolle and treate with Disitamab Vedotin, Sintilimab and S-1. During the study period, imaging examinations were conducted every 6-12 weeks to evaluate the tumor and whether it reached the operable standard. The scheme and duration of postoperative adjuvant treatment were determined by the investigator according to the patient's conditions (Sintilimab was recommended to be maintained for 1 year, and other drugs were increased or decreased according to the patient's conditions). During the study, safety evaluation and effectiveness evaluation will be conducted.
This is a phase II, one-arm study, which is aiming to evaluate the feasibility of combination of Disitamab Vedotin, Sintilimab and S-1 as conversion therapy in patients with HER2 overexpression unresectable gastric cancer .