A Multi-Country Study of the Clinical Course of Extensive-Stage Small Cell Lung Cancer: A Six-Study Analysis of Real-World Treatment Patterns and Outcomes.

Purpose: Small cell lung cancer (SCLC) is a highly aggressive malignancy with poor prognosis. Studies capturing the impact of recently approved immunotherapies are limited, highlighting a knowledge gap regarding their real-world use and effectiveness.  . Patients and Methods: We examined data from 29949 patients with extensive-stage (ES)-SCLC across observational studies from the United States, United Kingdom, Spain, Taiwan, South Korea, and Japan to describe the clinical course of ES-SCLC. Data sources included electronic health record databases, registries, and claims data over time periods ranging between 2013 and 2023. Patient characteristics, recent treatment patterns, and real-world overall survival (rwOS) were assessed in each country. Results: The most common first-line (1L) treatment was platinum plus etoposide without anti-PD-L1 agents (59-89%), followed by platinum plus etoposide with anti-PD-L1 agents (9-38%). Second-line (2L) and third-line (3L) treatments varied widely across countries. Median rwOS ranged from 8.1-11.3 months following 1L initiation, 4.8-6.9 months following 2L, and 4.1-5.5 months following 3L. Patients receiving compared to those not receiving 1L anti-PD-L1 therapy showed numerically higher median rwOS following 1L initiation, with no meaningful difference in rwOS following 2L or 3L therapy. Conclusion: In our evaluation of real-world treatment patterns and outcomes among patients with ES-SCLC from six countries, we found that rwOS in 1L, 2L and 3L was consistently poor across countries, despite differences in patient characteristics and treatment patterns. These findings may support the generalizability of clinical evidence across geographies and highlight the need for further research to optimize treatment strategies to improve patient outcomes globally.