Efficacy of rechallenge after first-line immunotherapy for advanced gastric cancer: A retrospective real-world study

We aimed to explore the efficacy of rechallenge after first-line immunotherapy in advanced gastric cancer (AGC) and to analyze the factors affecting prognosis based on clinical characteristics. Eighty-five AGC patients who underwent rechallenged after the failure of first-line treatment with immune checkpoint inhibitors (ICIs) were retrospectively collected from July 2019 to December 2022 in Jiangsu Cancer Hospital. Potential factors affecting prognosis were analyzed by univariate and multivariate Cox analysis. Survival analysis was performed by Kaplan-Meier method and Log rank test. Stratified factors included human epidermal growth factor receptor 2 (HER-2) and programmed cell death-ligand 1 combined positive score (PD-L1 CPS). The objective response rate (ORR) was 15.3%, and the disease control rate (DCR) was 74.1%. The median progression-free survival (PFS) was 4.8 months. Results showed that patients in the I + C group had the best response. The ORR was 20.0% VS 8.7% in the I + C group and I + C + AAD group. The DCR was 78.0% VS 65.2%, and the median PFS was 6.7 VS 4.7 months [hazard ratio (HR): 0.55, 95% confidence interval (CI): 0.30-1.00, p = .022]. The ORR was 20.0% VS 8.3% in the I + C group and I + C + ADC group. The DCR was 78.0% VS 75.0%, and the median PFS was 6.7 VS 4.4 months (HR: 0.59, 95%CI: 0.26-1.30, p = .112). The median PFS was 4.7 VS 4.4 months in the I + C + AAD group and I + C + ADC group (HR: 1.21, 95%CI: 0.60-2.47, p = .580). Adverse events (AEs) were found in 34 patients, mainly including leukopenia 9 (10.6%), and neutropenia 8 (9.4%). The incidence of grade 3-4 AEs was 8.2%. There were no drug-related deaths and all AEs were manageable. Rechallenge after first-line immunotherapy showed good survival benefit and acceptable safety in the therapy of AGC. Especially for patients with HER-2-positive and PD-L1 CPS ≥ 1%, rechallenge may be an effective treatment modality.