Immunotherapy retreatment with serplulimab vs. chemotherapy in extensive-stage advanced small cell lung cancer.

The present study compared the effectiveness and safety of immunotherapy retreatment with serplulimab vs. chemotherapy in extensive-stage small cell lung cancer (ES-SCLC). This real-world retrospective cohort study included patients with ES-SCLC who experienced failed first-line immunotherapy and received second-line immunotherapy retreatment (serplulimab) or chemotherapy. There were 67 and 93 patients in the serplulimab and chemotherapy groups, respectively. Progression-free survival (PFS) time was prolonged with the administration of serplulimab compared with chemotherapy [median, 7.65 vs. 5.25 months; hazard ratio (HR), 0.601; 95% confidence interval (CI), 0.426-0.848; P=0.003]; the results were similar after confounder adjustment in the multivariable Cox regression analysis (HR, 0.572; 95% CI, 0.395-0.828; P=0.003). The median overall survival (OS) time was 15.56 vs. 13.48 months (HR, 0.680; 95% CI, 0.478-0.966; P=0.031). Multivariable Cox regression analysis showed that serplulimab was also an independent protective factor for OS compared with chemotherapy (HR, 0.158; 95% CI, 0.096-0.261; P<0.001). The incidence of grade ≥3 adverse events was 29.9 and 34.4% with serplulimab and chemotherapy, respectively (P=0.760). In conclusion, immunotherapy retreatment with serplulimab is associated with prolonged PFS and OS times compared with chemotherapy in ES-SCLC, with a similar safety profile.