Combining Immunotherapy with Anlotinib in Extensive-Stage Small Cell Lung Cancer: A Multicenter Analysis of Efficacy and Safety

Background: Patients with extensive-stage small cell lung cancer (ES-SCLC) face considerable therapeutic challenges and limited survival outcomes. This study aimed to evaluate the efficacy and potential synergistic effects of combining immunotherapy (IT) with anlotinib in patients with ES-SCLC. Methods: We enrolled patients with ES-SCLC who received regular treatment at three centers from January 2020 to January 2024. Survival outcomes were compared using the Kaplan-Meier method and Cox proportional hazards regression. Results: A total of 147 eligible patients with ES-SCLC were included in the analysis. The median overall survival (mOS) for all patients was 15.5 months (95% CI, 13.9-17.1). In the chemotherapy combined with immunotherapy (CT+IT) group, the mOS was 17.8 months, compared to 12.6 months in the CT group (p = 0.055). The median progression-free survival (mPFS) was 7.1 months in the CT+IT group and 6.5 months in the CT group (p = 0.157). Additionally, when the cohort was divided into three groups (CT+IT+Anlotinib, CT+IT and CT alone), the mOS was 18.5, 16.3, and 12.6 months, respectively. A significant improvement in OS was observed in the CT+IT+Anlotinibgroup compared to the CT-alone group (p = 0.044), although there were no significant differences in PFS among the three groups (7.3 months vs. 6.9 months vs. 6.5 months). Multivariate analysis identified radiotherapy (p = 0.003) and immunotherapy (p = 0.021) as independent prognostic factors for OS, while liver metastasis (p = 0.023) and radiotherapy (p = 0.018) were independent predictive factors for PFS. Furthermore, patients treated with radiotherapy (RT) and CT showed significant improvements in OS (17.5 months vs. 12.5 months; p = 0.002) and PFS (7.3 months vs. 6.3 months; p = 0.004) compared to those who received CT alone. The rates of treatment-related adverse events were similar across the three groups (p = 0.721). Conclusion: An increasing number oftreatment options are being explored for ES-SCLC, and CT is the cornerstone of treatment for this disease. The combination of Anlotinib with IT can significantly prolong survival in patients with ES-SCLC, while maintaining an excellent safety profile, and such treatments are worthy of further exploration.