BC001 in Combination with Sintilimab and XELOX in the Treatment of HER-2 Negative Advanced or Metastatic Gastric Cancer or Gastroesophageal Junction Adenocarcinoma.

patients will be given : BC001 8mg/kg, 12mg/kg or 16mg/kg intravenously once every three weeks; Sintilimab 3mg/kg（body weight\<60kg）or 200mg（body weight≥60kg）intravenously once every three weeks; Oxaliplatin 130mg/m2 intravenously once every three weeks; Capecitabine 1000mg/m2 orally once daily in the first two weeks of each three-week treatment cycle.