SOX Combined With Sintilimab and Trastuzumab Versus SOX Regimen in the Perioperative Treatment of HER2-positive Locally Advanced Gastric Adenocarcinoma

Sintilimab 200mg was administered as a 30-60 min intravenous (IV) infusion every 3 weeks.3 cycles before surgery and 5 cycles after surgery.

Trastuzumab was 8mg/kg for the first time, and 6mg/kg for the follow-up. 3 cycles before surgery and 5 cycles after surgery.

"Oxaliplatin 130 mg/m2 was administered IV every 3 weeks. S-1 was given orally twice daily for the first 2 weeks of each 3-week cycle. The S-1 dose was 40 mg for body surface area (BSA) \< 1.25 m2, 50 mg for BSA 1.25 to \<1.5 m2 and 60 mg for BSA ≥1.5 m2.~Body surface area \&lt;1.25m2: Tegio 40mg bid day 1 \~ 14; Body surface area 1.25 \~ \&lt;1.5m2: Tegio 50mg bid day 1 \~ 14; Body surface area ≥1.5m2: Tegio 60mg bid day 1 \~ 14; 3 cycles before surgery and 3 cycles after surgery."