Comparing the Efficacy of Sintilimab Plus Nab-POF Regimen, Sintilimab Plus XELOX Chemotherapy, and Lenvatinib, Sintilimab Plus XELOX Chemotherapy in the Treatment of HER2-negative, Metastatic Gastric Cancer

This trial is a prospective, open, randomized, phase II clinical study. It compares the current first-line treatment for advanced gastric cancer in phase II clinical trials, with the best efficacy being the combination of orient-16 study with sintilimab and XELOX regimen. The purpose of this study is to evaluate whether adding anti-angiogenic drugs or chemotherapy drugs on the basis of two-drug chemotherapy regimen (XELOX regimen) and PD-1 monoclonal antibody can improve efficacy for advanced gastric cancer.