Real-World Effectiveness and Safety of Immune Checkpoint Inhibitors Combined with Chemotherapy in Taiwanese Patients with Extensive-Stage Small Cell Lung Cancer

Abstract

Purpose: Extensive-stage small cell lung cancer (ES-SCLC) has poor prognosis. While immune checkpoint inhibitors (ICIs) with chemotherapy show survival benefits in trials, real-world data from Asia are scarce. This study evaluates real-world efficacy and safety of chemotherapy with or without ICIs in Taiwanese patients with ES-SCLC and identifies survival predictors. Materials and Methods: A retrospective cohort study analyzed 114 patients with ES-SCLC treated between 2017 and 2023 at four Taiwanese medical centers. Patients received first-line chemotherapy alone (n = 68) or with ICIs (atezolizumab, durvalumab, pembrolizumab; n = 46). Primary endpoints were overall survival (OS) and progression-free survival (PFS), assessed via Kaplan–Meier methods and Cox regression. Results: Baseline characteristics were comparable, except poorer ECOG performance (≥2) in the chemotherapy group (27% vs. 9%; p = 0.021). IO–chemotherapy significantly improved OS (16.1 vs. 9.4 months; HR = 0.32, 95% CI: 0.20–0.52; p < 0.001) and PFS (7.8 vs. 5.5 months; HR = 0.40, 95% CI: 0.26–0.63; p < 0.001). Multivariate analysis confirmed IO–chemotherapy as an independent positive predictor (OS adjusted HR = 0.25, 95% CI: 0.14–0.44; PFS adjusted HR = 0.37, 95% CI: 0.22–0.61; both p < 0.001). Skin rash was more common with IO–chemotherapy (24% vs. 3%; p < 0.001). Immune-related adverse events (AEs) correlated with improved survival (median OS: 21.4 months with 1–2 AEs, 16.6 months with 3–4 AEs, 12.5 months without AEs). Conclusion: Immunochemotherapy significantly improves survival in Taiwanese patients with ES-SCLC, with manageable toxicity, supporting ICIs’ incorporation into standard treatment.