RATIONALE 311: tislelizumab plus concurrent chemoradiotherapy for localized esophageal squamous cell carcinoma.

Lay abstract Esophageal cancer is a challenging disease that seriously threatens patients' health and life. Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer. Most patients who have inoperable stage II­IV ESCC are currently treated with a sequential combination of chemotherapy and radiation therapy, with the hopes of increasing the positive effects seen from either therapy alone. Immune checkpoint inhibitors such as anti-PD-1/PD-L1 antibodies have shown encouraging results in patients with ESCC, but it is not known if combining checkpoint inhibitors with simultaneous chemotherapy and radiation therapy will provide additional benefits. The safety and efficacy of tislelizumab, an anti-PD-1 antibody specifically engineered to limit potential resistance to anti-PD-1 therapy, is being investigated in combination with simultaneous chemotherapy and radiation therapy in patients with inoperable stage II­IV ESCC in an actively enrolling clinical trial, RATIONALE 311 (NCT03957590). Our trial in progress article explains the reason RATIONALE 311 was started and provides important enrollment information for doctors. Clinical trial registration: NCT03957590 (ClinicalTrials.gov).