Study of Camrelizumab (SHR-1210) and Apatinb Based Therapies for Alpha-fetoprotein (AFP)-Producing Gastric Cancer or Gastroesophageal Junction Adenocarcinoma

This is a study of Camrelizumab (SHR-1210) and Apatinb for unresectable Recurrent or metastatic alpha-fetoprotein (AFP)-producing gastric cancer or Gastroesophageal Junction Adenocarcinoma. Camrelizumab combined with Apatinib and standard chemotherapy will be given to treatment-naïve participants; Camrelizumab combined with Apatinib will also be evaluated in participants who have had ≥ 1 line of previous treatment. The primary endpoint is the Overall Response Rate (ORR).