This is a multicenter, randomized, controlled trial to evaluate the efficacy and safety of Maintenance Treatment with Capecitabine plus Apatinib, Apatinib and Observation after First-line XELOX/SOX chemotherapy for Patients with Advanced Gastric Cancer

Inclusion Criteria:

1. aged 18-75；
2. had histologically confirmed unresectable and/or metastatic (primary or recurrent) adenocarcinoma of the stomach or gastroesophageal junction；
3. received 4-6 cycles of Xelox/SOX regimens as first-line chemotherapy and the response was not progression disease (PD);
4. ECOG 0-2；
5. Patients were tested for tumor HER2 status before treatment, and patients with HER2-negative disease；
6. presence of at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 guidelines；
7. Subjects has to voluntarily join the study and sign the Informed Consent Form for the study;
8. Adequate organ function as defined below: Hematologic ANC ≥ 2*109/L, Platelets ≥ 100*109/L, AST and ALT ≤ 2.5×ULN, TBIL ≤ 1.5×ULN
9. Receiving no form of chemotherapy, targeted therapy or other study medication;

Exclusion Criteria:

1. previous radiotherapy to the abdomen；
2. previous treatment for advanced disease (neoadjuvant chemotherapy was permitted if administered >6 months before enrollment)；
3. pregnant or lactating women or women of childbearing potential；
4. disease progression during the first-line chemotherapy;
5. active gastrointestinal bleeding, arterial thrombosis or cerebrovascular accident within 6 months before enrollment
6. previous treatment of apatinib and Ramucirumab