A Study of PD-1 Inhibitors Combined With Fruquintinib and Chemotherapy in First-line Treatment of HER2-negative Advanced G/GEJ Cancer

"Combined treatment period: A total of 6 cycles of combined treatment Fruquintinib: 4 mg/d, qd po, d1-14, q3w. Nivolumab: 360mg iv.gtt d1, q3w or Sintilimab: 200mg iv.gtt d1, q3w SOX : Oxaliplatin 130mg/m2 iv.gtt d1, Teysuno 40mg/m2 p.o.b.i.d. d1\~ 14q3w. Or XELOX regimen: oxaliplatin 130mg/m2 iv.gtt d1 Capecitabine 1000mg/m2 p.o. b.i.d. d1\~ 14q3w.~Maintenance treatment period:~Fruquintinib: 4 mg/d, qd po, d1-14, q3w. Nivolumab: 360mg iv.gtt d1, q3w or Sintilimab: 200mg iv.gtt d1, q3w Teysuno 40mg/m2 p.o.b.i.d. d1\~14 q3w or Capecitabine 1000mg/m2 p.o.b.i.d. d1\~14 q3w.~Maintenance of treatment until disease progression or toxicity becomes intolerable."