Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants With Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-585/KEYNOTE-585)-China Extension

The First Affiliated Hospital of Wenzhou Medical University (Site 0652), Wenzhou

Beijing Friendship Hospital ( Site 0637), Beijing

Beijing Cancer Hospital ( Site 0221), Beijing

The First Hospital of Jilin University-Gastrointestinal Surgery ( Site 0234), Changchun

Renji Hospital Shanghai Jiao Tong University School of Medicine ( Site 0642), Shanghai

The Affiliated Hospital of Xuzhou Medical College-Oncology ( Site 0645), Xuzhou

Afflilated Hospital of Bengbu Medical College-Surgical Oncology (Site 0638), Bengbu

Shandong Provincial Hospital-Gastrointestinal Surgery ( Site 0640), Jinan

The Affiliated Hospital of Qingdao University ( Site 0636), Qingdao

Zhejiang Provincial People's Hospital-Oncology (Site 0656), Hangzhou

Zhejiang Cancer Hospital ( Site 0231), Hangzhou

Fujian Medical University Union Hospital-1 Bingfanglou-Gastric Surgery Department (Site 0632), Fuzhou Fujian

Fujian Provincial Cancer Hospital ( Site 0230), Fuzhou

Sir Run Run Shaw Hospital ( Site 0233), Hangzhou

Henan Cancer Hospital (Site 0227), Zhengzhou

The First Affiliated Hospital, Sun Yat-sen University (Site 0635), Guangzhou

The First Affiliated Hospital of Guangzhou Medical University ( Site 0224), Guangzhou

Sichuan Cancer hospital, Chengdu

Tangdu Hospital of Fourth Military Medical University of Chinese People's Liberation Army ( Site 0647), Xi'an

Fourth Hospital of Hebei Medical University ( Site 0633), Shijiazhuang