Adebrelimab in Small Cell Lung Cancer: From Current Advances to Emerging Combination Strategy and Challenge

Adebrelimab is a fully humanized monoclonal antibody against programmed cell death-ligand 1 (PD-L1) that has been approved in combination with chemotherapy as the first-line treatment for extensive-stage small cell lung cancer (ES-SCLC). This approval was driven by the landmark CAPSTONE-1 trial, where adebrelimab demonstrated superior survival outcomes: median overall survival (mOS) improved from 12.8 to 15.3 months (HR=0.72, p=0.0017) and 3-year survival rates doubled (21.1% vs 10.5%) compared to chemotherapy alone. Based on this systemic treatment, addition of sequential thoracic radiotherapy achieved unprecedented mOS of 22.9 months in a Phase II trial. In limited-stage small cell lung cancer (LS-SCLC), the initial results of adebrelimab combined with concurrent chemoradiotherapy are promising. Whether in first-line or later-line treatment, there are numerous ongoing clinical trials to explore the potential of the novel adebrelimab-based regimen, and the results are highly anticipated. Despite ongoing efforts to identify biomarkers that may guide treatment decisions, no validated prognostic or predictive biomarkers are currently available for SCLC. This review summarizes the present role of adebrelimab in SCLC and outlines novel strategies aimed to further improve survival outcome.