Protocol digest of a randomized phase III trial comparing S-1-based chemoradiotherapy with/without nivolumab for unresectable locally advanced or borderline resectable pancreatic cancer: JCOG1908E (PENETRATE).

Pancreatic cancer remains a highly lethal disease with a 5-year survival proportion of <10%. Chemoradiotherapy is a treatment option for unresectable locally advanced (UR-LA) or borderline resectable (BR) pancreatic cancer, but its efficacy is not sufficient. Induction of the synergistic effect of irradiation and immune checkpoint inhibitors can be an attractive strategy. An open-label randomized phase III trial has been conducted since October 2020 to confirm the superiority of nivolumab plus S-1-based chemoradiotherapy over S-1-based chemoradiotherapy alone in patients with UR-LA or BR pancreatic cancer. A total of 216 patients will be enrolled in 14 institutions within 3.5 years. The primary endpoint of the safety run-in part is dose-limiting toxicity, and that of the phase III part is overall survival. This trial was registered at the Japan Registry of Clinical Trials as jRCT2080225361 (https://jrct.niph.go.jp/latest-detail/jRCT2080225361).