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.