Immune checkpoint inhibitor retreatment in second-line treatment of esophageal cancer: A real-world study.

e16034 Background: Immunotherapy combined with chemotherapy has been recommended in several guidelines and consensus for the first-line treatment of advanced esophageal cancer(EC), but it is controversial whether to continue immune checkpoint inhibitors (ICIs) after the progress of first-line immunotherapy. Methods: This was a single-center, retrospective, observational, real-world study to collect general conditions and clinical data of EC patients hospitalized in the First Affiliated Hospital of Henan University of Science and Technology between February 2020 and December 2023. All patients received programmed cell death protein 1 (PD-1) or its ligand (PD-L1) inhibitor combination therapy in the first-line and received at least two cycles of PD-1/PD-L1 inhibitor-based therapy in the second-line setting after progression. We evaluated the efficacy and safety including overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), grade 3-5 treatment-related adverse effects (TRAE) and immune-related adverse events (irAEs). We also evaluated the relationship between clinical features and outcomes using univariate and multivariate analyses. Results: We enrolled 214 patients, with a median age 67.9 (47 – 87) years, male sex 66.8%, 201(93.9%) ESCC and 11(5.1%) EAC. In all patients, the mOS and mPFS were 9.6 (95%CI 9.1-10.1) months and 4.4 (95%CI 4.1-4.7) months; The ORR was 33.2%, DCR was 65.9%. 162 (75.7%) patients treated with immunochemotherapy(I+C), 37 (17.3%) patients received immunotherapy combined with anti-angiogenic drugs(I+A) and 15 (7.0%) patients treated with immunotherapy combined with chemotherapy and anti-angiogenic drugs(I+C+A). The mOS were 9.1 (95% CI 8.4 – 9.8) months, 10.0 (95% CI 8.7 – 11.3) months and 11.5 (95% CI 10.7 – 12.3) months, respectively. The mPFS were 4.3m (95%CI 4.0-4.6) months, 4.3 (95%CI 4.0-14.6) months and 6.0 (95%CI 4.2-6.4) months. mPFS and mOS did not have significant difference between these groups. Univariate and multivariate analyses showed that PFS more than 6 months on first-line therapy was an independent prognostic factor for PFS and OS in second-line therapy. The incidence of grade ≥ 3 TRAEs and irAEs were 25.7% and 5.6%. No treatment-related deaths occurred. Conclusions: This real-world data showed PD-1 or PD-L1 inhibitors retreatment might have good efficacy and manageable safety in EC patients who progress after first-line immunochemotherapy. [Table: see text]