A Study of the Advanced Adenocarcinoma of Stomach and Gastroesophageal Junction With Camrelizumab+SOX Control Camrelizumab+SOX+ Trastuzumab

Conditions

camrelizumab — DRUG
camrelizumab was administered intravenously at a fixed dose of 200 mg, on the first day, once every 3 weeks, with a cycle of 3 weeks. Infusion for 30 min each time (no less than 20 min and no more than 60min); SOX: Oxaliplatin: 130 mg/m2, administered intravenously, on the first day, once every three weeks, and every three weeks is a cycle; S-1: according to BSA (\< \<1.25 40 mg；; 1.25-1.5 50 mg； \> \>1.5 60 mg), oral administration, d1-d14 twice a day, 3 weeks as a cycle; Trastuzumab was administered intravenously, with an initial loading dose of 8 mg/kg and a subsequent dose of 6 mg/kg, with a cycle of 3 weeks.

Experimental: Cohort 1
camrelizumab was administered intravenously at a fixed dose of 200 mg, on the first day, once every 3 weeks, with a cycle of 3 weeks. Infusion for 30 min each time (no less than 20 min and no more than 60min); SOX: Oxaliplatin: 130 mg/m2, administered intravenously, on the first day, once every three weeks, and every three weeks is a cycle; S-1: according to BSA (\< \<1.25 40 mg；; 1.25-1.5 50 mg； \> \>1.5 60 mg), oral administration, d1-d14 twice a day, 3 weeks as a cycle; Trazumab was administered intravenously, with an initial loading dose of 8 mg/kg and a subsequent dose of 6 mg/kg, with a cycle of 3 weeks
Active Comparator: Cohort 2
camrelizumab was administered intravenously at a fixed dose of 200 mg, on the first day, once every 3 weeks, with a cycle of 3 weeks. Infusion for 30 min each time (no less than 20 min and no more than 60min); SOX: Oxaliplatin: 130 mg/m2, administered intravenously, on the first day, once every three weeks, and every three weeks is a cycle; S-1: according to BSA (\< \<1.25 40 mg；; 1.25-1.5 50 mg； \> \>1.5 60 mg), oral administration, d1-d14 twice a day, 3 weeks as a cycle;

Pathological complete response rate(pCR） [ Time Frame: up to 2 years ]