Protocol digest of a randomized controlled Phase III study comparing surgery alone versus adjuvant nivolumab versus adjuvant S-1 for locally advanced oesophageal squamous cell carcinoma with no pathological complete response after neoadjuvant chemotherapy followed by curative esophagectomy: Japan Clinical Oncology Group study JCOG2206 (SUNRISE Trial)

Although the efficacy of postoperative therapy with nivolumab after preoperative chemoradiotherapy for locally advanced oesophageal cancer has been proven in Western countries, the survival benefits of postoperative therapy after preoperative chemotherapy with docetaxel, cisplatin and 5-FU or cisplatin plus 5-FU as the Japanese standard therapy remain controversial. This randomized Phase III trial was designed to confirm the superiority of postoperative therapy with nivolumab over observation alone and S-1 over observation alone in patients with locally advanced oesophageal squamous cell carcinoma with no pathological complete response after preoperative chemotherapy followed by curative esophagectomy. A total of 450 patients will be enrolled from 56 hospitals in Japan over 5.5 years. The primary endpoint is relapse-free survival, and the secondary endpoints are disease-free survival, overall survival, adverse events and incremental cost-effectiveness ratio. This trial has been registered in the Japan Registry of Clinical Trials as jRCTs031230219 (https://jrct.niph.go.jp/latest-detail/jRCTs031230219).