Clinical efficacy and safety of immune checkpoint inhibitors plus anlotinib as secondline or subsequent therapy in extensive stage small cell lung cancer: a retrospective study.

Background: Treatments are limited for extensive stage small cell lung cancer (ES-SCLC) patients in secondline or subsequent setting. This study aimed to explore the clinical efficacy and safety of immune checkpoint inhibitors (ICIs) plus anlotinib as secondline or subsequent therapy in ES-SCLC.

Methods: We retrospectively analyzed 116 patients with ES-SCLC at Shandong Provincial Qianfoshan Hospital between January 2019 and March 2024. According to the different therapy regimes, they were divided into three groups, ICI plus anlotinib as secondline or subsequent therapy group (ICI + anlotinib group), single ICI as secondline or subsequent therapy group (single ICI therapy group), single chemotherapy as secondline therapy group (single chemotherapy group). Kaplan-Meier method was used to compare the progression-free survival (PFS) and the overall survival time (OS) among these three groups. Cox regression analysis was used to analyze different factors which correlated to PFS and OS. The adverse events were assessed according to the Common Terminology Criteria for Adverse Events version 5.0.

Results: Kaplan-Meier analysis showed that patients in ICI + anlotinib group had a longer PFS and OS compared to patients in single ICI therapy group (median PFS [mPFS]: 6.7 months vs. 4.6 months, P = 0.007; median OS [mOS]:12.4 months vs. 8.4 months, P = 0.041) and single chemotherapy group (mPFS: 6.7 months vs. 3.0 months, P < 0.001; mOS: 12.4 months vs. 7.2 months, P = 0.002). The Cox regression analysis showed that the Eastern Cooperative Oncology Group performance status (ECOG PS), liver metastasis, brain metastasis and treatment regimes were independent predictors that affecting the PFS and OS of all the enrolled patients. The common adverse events (AEs) were wleukopenia and fatigue. There was no significant statistical difference in other AEs among the three groups except for leukopenia.

Conclusion: ICI + anlotinib as secondline or subsequent therapy has better efficacy than single ICI group and single chemotherapy group and with tolerable toxicities for patients with ES-SCLC.