Effect of continued immunotherapy on survival of extensive-stage small cell lung cancer: A retrospective analysis.

person Zhuoran Sun Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Science, Jinan, China info_outline Zhuoran Sun, Shuangqing Lu, Hui Zhu, Yaru Tian

Authors person Zhuoran Sun Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Science, Jinan, China info_outline Zhuoran Sun, Shuangqing Lu, Hui Zhu, Yaru Tian Organizations Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Science, Jinan, China, Shandong Cancer, Jinan, China, Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China Abstract Disclosures Research Funding No funding sources reported Background: Immunotherapy has shown significant survival advantages in the first-line treatment of extensive-stage small cell lung cancer (ES-SCLC),and the second-line treatment options for ES-SCLC are gradually attracting wider attention. The aim of this study was to evaluate the clinical efficacy of continued immunotherapy as the second-line treatment for ES-SCLC. Methods: Between September 2020 and August 2023, the study included 207 patients diagnosed with ES-SCLC, all of whom progressed after first-line immunotherapy plus chemotherapy. The primary endpoints was progression-free survival (PFS) from the first disease progression to the second progression or date cutoff. And the second endpoints were overall survival(OS) from diagnosis to death or date cutoff and adverse events (AEs).OS and PFS were calculated using the Kaplan-Meier method, and compared using the log-rank test. Results: Overall, 124 patients were included in the continued immunotherapy group, and 83 patients in the control immunotherapy group. The basic characteristics of patients included age: 62.3% below 65 years old and 37.7% over or equal 65 years old; Most patients had KPS scores≥80 (85%),138 patients (66.7%) had baseline liver metastases, and 146 patients(70.5%) had baseline brain metastases.The continued second-line immunotherapy (including PD-L1 inhibitors and PD-1 inhibitors) did not prolong OS (median:18.03 vs. 21.34 months, HR=1.15,p=0.47) and PFS (median:4.30 vs. 4.43 months,HR=1.29,p=0.19) compared with the control. In the subgroup analysis, there were no significant differences in PFS among patients with partial response (PR, median:4.46 vs 4.43 months, HR=1.35,p=0.10) and stable disease (SD, median:4.75 vs 3.08 months HR=0.81, p=0.56), as well as in OS among patients with partial response (PR, median:18.43 vs 21.34 months, HR=1.15,p=0.53) and stable disease (SD, median:14.98 vs 17.80 months HR=0.95,p=0.90).I n the continued immunotherapy group, PFS was not significantly different between continued PD-L1 inhibitor group and PD-1 inhibitor group (median: 4.26 vs 4.59 months HR=1.04,p=0.17). There was no significant difference in adverse effects between the groups. Conclusions: Continued immunotherapy did not prove survival of ES-SCLC patients progressed after the standard first-line immunotherapy plus chemotherapy, neither efficacy nor type of immune checkpoint inhibitors produces benefit after progression in ES-SCLC patients.