Nivolumab versus chemotherapy in patients with advanced oesophageal squamous cell carcinoma refractory or intolerant to previous chemotherapy (ATTRACTION-3): a multicentre, randomised, open-label, phase 3 trial

National Cancer Center Hospital East, Yonsei University, Tohoku University Hospital, Hiroshima University Hospital, China Medical University Hospital, China Medical University, Japanese Foundation For Cancer Research, Aichi Cancer Center, Samsung Medical Center, Sungkyunkwan University, Keio University, Osaka University Hospital, National Yang Ming Chiao Tung University, Taipei Veterans General Hospital, Showa University Hospital, Ulsan College, Asan Medical Center, University of Ulsan, National Taiwan University Hospital, Odense University Hospital, Bristol-Myers Squibb (United States), Ono Pharmaceutical (Japan)