S1+ Paclitaxel (IV&IP) + Bevacizumab (IP) Versus S1+Oxaliplatin as First-line Treatment in Gastric Cancer With Malignant Ascites

Inclusion Criteria:

• 18 years ≥ Age≤ 70 years, male or female

• Pathologically confirmed adenocarcinoma of the gastric or gastro-oesophageal junctionwith inoperable locally advanced or recurrent and/or metastatic disease; with mediumamount of malignant ascites which can be catheterized.

• Diagnostic criteria for malignant ascites (meet any of the following criteria):ascites cytology positive; or imaging or pathological confirmed peritoneal metastases.

• No prior anti-tumor treatment to the metastatic disease; an interval of at least 6months from the last adjuvant chemotherapy.

• Eastern Cooperative Oncology Group (ECOG) performance status( PS) score 0-1.

• Normal major organ function, and laboratory tests must meet the following criteria:hemoglobin (HGB) ≥ 90 g/L, neutrophil count ≥ 1.5×109/L, platelet count ≥ 100×109/L,total bilirubin (TBil) ≤ 1.5 upper normal limitation (UNL), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 UNL, serum creatinine (Cr) ≤ 1 UNL;creatinine clearance rate (CCr) ≥ 60 ml/min (calculated using the Cockcroft-Gaultequation).

• International Normalized Ratio (INR) ≤ 1.5 and partial prothrombin time (PPT) oractivated partial thromboplastin time (APTT) ≤ 1.5 UNL within 7 days beforeenrollment.

• Life expectancy of at least 12 weeks

• Signed informed consent (ICF)

• For women of child bearing potential, a negative serum or urine pregnancy test resultshould be obtained with 7 days before enrollment; Women of childbearing potential andmen must agree to use adequate contraception before entering the program until atleast 8 weeks after the last study drug administration.

Exclusion Criteria:

• Known hypersensitivity or allergic to any of the study drugs, study drug classes, orexcipients in the formulation.

• Subject received chemotherapy to the metastatic disease (except adjuvant/neoadjuvantchemotherapy administered 24 weeks before enrollment)

• Subject with other malignancies, except for non-melanoma skin cancer or in-situcervical carcinoma under adequate treatment, or other treated malignancies withoutevidence of recurrent for 5 years.

• Anti-tumor cytotoxic drug therapy within 14 days prior to enrollment（longer washouttime interval might needed depends on drug characteristics）

• Uncontrolled hypertension which cannot be reduced to normal range by antihypertensiveagents [Systolic Blood Pressure(SBP) >140 mmHg, diastolic blood pressure (DBP) > 90mmHg], coronary artery disease > grade 1, arrhythmia > grade 1 [including correctedQT(QTc) interval prolongation: QTc＞450 ms for male，QTc＞470 ms for female], grade 1heart failure.

• Proteinuria ≥ ++，or persistent proteinuria > 1.0 g/24 hours

• Presence of any toxicity ≥ grade 1 according to NCI-CTCAE except for alopecia.

• Arterial or venous thrombotic or embolic events such as cerebrovascular accident (including transient ischemic attacks, cerebral hemorrhage、cerebral infarction), deepvein thrombosis and pulmonary embolism within 12 months before enrollment.

• Bowel obstruction within 6 weeks before enrollment.

• Surgical treatment was performed within 6 weeks before enrollment. Subject shouldrecover from any major surgery.

• Serious uncontrolled systemic illness or medical condition or uncontrolled infections,including but not limited to: uncontrollable ventricular arrhythmias, history ofdocumented myocardial infarction within 3 months, uncontrollable epileptic dementia,unstable spinal compression, superior vena cava syndrome, extensive bilateralinterstitial pulmonary disease by high-resolution computed tomography (HRCT), or anyneurological or mental abnormalities which affect compliance.

• Human immunodeficiency virus (HIV) positive

• Pregnancy or lactation women

• Cannot be orally administered medication

• Subject with a tendency for gastrointestinal hemorrhage. Including: Black stool orhematemesis within 2 months; For subjects positive in occult test with unresectedprimary lesion, if the principle investigator in each center considers withpossibility of gastrointestinal hemorrhage, the subject could not be enrolled.

• Subject with malignant pleural effusion need medical intervention.

• A history or evidence of hereditary hemorrhagic constitution or coagulation disorderthat increases the risk of bleeding

• Subjects with central nerve system metastases

• Have been enrolled in other clinical trial with investigational drug treatment withinthe 4 weeks of start of study treatment

• For subject with bone metastases, palliative radiotherapy was given 4 weeks beforeenrollment (radiation field >5%).

• Any other disease or condition that the investigator considers not suitable forparticipating in this clinical trial.