Abstract 5098: Second-line treatment outcomes in Extensive Stage Small Cell Lung Cancer (ES-SCLC) patients after first-line immuno-chemotherapy

Abstract Background: First-line immune checkpoint inhibitors (ICIs) has significantly improved overall survival (OS) of ES-SCLC. However, second-line treatment options are still controversial with limited overall survival. This study aims to evaluate the efficacy of different second-line regimens for relapsed ES-SCLC after first-line immuno-chemotherapy. Patients and Methods: We retrospectively reviewed 96 ES-SCLC patients receiving first-line immuno-chemotherapy in Cancer Hospital Chinese Academy of Medical Sciences, from Jan 2019 to Dec 2022. Clinical data were collected from electronic medical records. The clinical outcomes, including objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan-Meier method and standard log-rank test. Results: From January 4, 2019 to December 18, 2022, a total of 96 ES-SCLC patients received first-line immuno-chemotherapy and 49 of them went through second-line treatment in our center. Patient characteristics were listed as follows : median age 63 (31-79), male 76 (79.2%) , heavy smoker 59 (61.5%), liver metastasis 40 (41.7%), brain metastasis 33 (34.4%) and refractory recurrence 58 (60.4%). Second-line treatments included immunotherapy crossover and combination with chemotherapy (n=40), anlotinib with or without chemotherapy (n=5), chemotherapy alone (n=4). ORR of the whole group in the second-line setting was 22.4%. Median PFS was 3.23 months (95% CI 1.96-4.50). Cross-line immunotherapy failed to improved survival for relapsed ES-SCLC compared with those without ICIs ( mPFS 3.23 vs 3.13m, p=0.829). Anlotinib based treatment showed numerically superior PFS for relapsed SCLC compared with those without anlotinib therapy (mPFS 6.00 vs 3.13m, p=0.089). Conclusion: This retrospective study indicated cross-line ICIs failure to improve clinical outcome for relapsed ES-SCLC, and implied the potential benefits of anlotinib in second-line setting. Citation Format: Rui Wan, Linjie Fan, Jia Zhong, Jianchun Duan, Zhijie Wang, Xuezhi Hao, Jie Wang. Second-line treatment outcomes in Extensive Stage Small Cell Lung Cancer (ES-SCLC) patients after first-line immuno-chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5098.