Safety and efficacy of ICI plus anlotinib vs. anlotinib alone as third-line treatment in extensive-stage small cell lung cancer: a retrospective study

PURPOSE: The objective of this study was to evaluate the safety and efficacy of immune checkpoint inhibitor (ICI) plus anlotinib as third-line treatment in extensive-stage small cell lung cancer (ES-SCLC). METHODS: A total of 120 patients with ES-SCLC who were admitted to Shandong Cancer Hospital between January 2019 and December 2020 were retrospectively analyzed. They were divided into the observation group (n = 62) and the control group (n = 58) according to their different treatment plans. The observation group was given ICI plus anlotinib, while the control group was given anlotinib alone. The primary endpoint of the study was progression-free survival (PFS), and the secondary endpoints were the objective response rate (ORR) and disease control rate (DCR). An efficacy evaluation was carried out every 6 weeks. Univariate and multivariate analyses were performed to identify the prognostic factors. The main treatment-related adverse events were evaluated according to the Common Terminology Criteria for Adverse Events version 5.0. RESULTS: In the observation group and the control group, the DCRs were 87.1% and 72.4% (p = 0.044), and the ORRs were 19.4% and 6.9% (p = 0.045), respectively. The median PFS was longer in the observation group (7.5 months) than in the control group (4.6 months) (p = 0.0033). In Cox regression analysis, the Eastern Cooperative Oncology Group performance status score, brain metastases and metastatic sites were prognostic factors of ICI plus anlotinib. Compared with the control group, grade 1–2 immune-related pneumonia and hypothyroidism of patients in the observation group were significantly increased (p < 0.05), but grade 3–4 treatment-related adverse reactions were not significantly increased (p > 0.05). CONCLUSION: ICI plus anlotinib showed promising efficacy and manageable toxicity in third-line treatment of ES-SCLC.