Ph1b/2 Study of the Safety and Efficacy of SHR-A1811 Combinations in Advanced HER2 Expression Gastric Cancer

Inclusion criteria

• Age from 18 to 75, Male and female participants
• Local advanced unresectable or metastatic disease Pathologically documented adenocarcinoma of gastric or gastroesophageal junction;
• HER2 expression ;
• Phase Ib: Failed or intolerant to prior standard treatment, or did not receive any systemic anti-tumor therapy; Phase II: previously untreated patients;
• ECOG 0-1;
• The expected survival ≥3 months;
• Sufficient bone marrow and organ functions;

Exclusion criteria

• There were ascites, pleural effusion and pericardial effusion that needed to be treated;
• Major surgery was performed within 4 weeks;
• Have active autoimmune disease or history of autoimmune disease;
• Patients with interstitial pneumonia;
• There was severe infection within 4 weeks before starting the study treatment;
• Patients with active pulmonary tuberculosis infection history within 1 year before enrollment;
• Serious cardiovascular and cerebrovascular diseases;
• Gastrointestinal perforation and/or gastrointestinal fistula occurred within 6 months before enrollment;