The first patient has been dosed in the global, phase III clinical trial of tislelizumab (BGB-A317, anti-programmed death-ligand 1 antibody, BeiGene, China), as second-line treatment in patients with advanced unresectable or metastatic esophageal squamous cell carcinoma (ESCC). Approximately 450 patients are planned to be enrolled in China, Japan, Korea, Belgium, France, Germany, Italy, Spain, the United Kingdom, and the United States. The trial’s primary endpoint is overall survival, and secondary endpoints include progression-free survival, objective response rate, duration of response, health-related quality of life, safety, and tolerability. This study is the third trial conducted under strategic collaboration of Celgene and BeiGene on tislelizumab. Tislelizumab is also being studied in global phase III trials in non-small cell lung cancer and hepatocellular carcinoma and 2 pivotal phase II trials in China in relapsed/refractory classical Hodgkin lymphoma and urothelial cancer. These studies are designed to support regulatory filings both in China and globally.