NCT05216237 2022-04-11A Study to Evaluate the Efficacy and Safety of Sintilimab Plus Apatinib and Chemotherapy in Patients With HER-2 Negative Microsatellite Stability (MSS) Advanced or Metastatic Gastric (GC) or Gastroesophageal Junction (GEJ) CancerAffiliated Hospital of Qinghai UniversityPhase 2 Unknown31 enrolled