Survival outcomes with first-line platinum–etoposide plus durvalumab versus platinum–etoposide alone in extensive-stage small cell lung cancer with metastatic disease including brain metastases: A real world analysis.

e20138 Background: Patients with extensive-stage small cell lung cancer (ES-SCLC) frequently present with metastatic disease, including brain metastases, and have poor survival outcomes. Immune checkpoint inhibitors combined with platinum–etoposide chemotherapy are widely used. However, real-world data on how well they work in patients with central nervous system involvement and other metastatic sites is still limited. We compared survival outcomes associated with first-line platinum–etoposide with versus without durvalumab in a large real-world ES-SCLC population with metastatic disease, including brain metastases. Methods: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network. Adult patients (≥18 years) with documented ES-SCLC and metastatic disease, including brain and extracranial metastases, who initiated first-line platinum–etoposide chemotherapy between March 2018 and January 2025 were identified. They were then stratified based on whether they received durvalumab. In order to balance baseline demographics and clinical comorbidities, a 1:1 nearest-neighbor propensity score-matching approach was used. Overall survival (OS) was the primary endpoint, and survival was estimated using the Kaplan–Meier method, while hazard ratios (HRs) were derived from Cox proportional hazards models. Results: Among 19,322 eligible patients, 1,087 received platinum–etoposide plus durvalumab while 18,235 received platinum–etoposide alone. Post propensity score matching, 1,087 patients were included in each cohort with well-balanced baseline characteristics (standardized differences < 0.1). Median OS was significantly longer in the durvalumab cohort than in the chemotherapy-alone cohort (643 vs 406 days). Survival probability at the end of follow-up was 34.4% versus 24.1%, respectively. Durvalumab-based therapy was associated with a significantly lower risk of death (HR 0.71; 95% CI 0.63–0.80; log-rank p < 0.001). Conclusions: In this comprehensive real-world analysis of ES-SCLC with advanced metastatic disease, including brain metastases, first–line platinum–etoposide plus durvalumab was associated with markedly improved overall survival compared with platinum–etoposide alone. These outcomes support the effectiveness of durvalumab-based chemo-immunotherapy in routine clinical practice among high-risk ES-SCLC populations.