Key Clinical Summary: 

• Design/Population: The phase 3 CAPSTONE-1 trial randomized 462 patients with previously untreated extensive-stage small cell lung cancer to receive adebrelimab plus chemotherapy or chemotherapy alone. Updated results reflect approximately 5 years of follow-up.
• Key Outcomes: Adebrelimab plus chemotherapy significantly improved overall survival and sustained long-term survival rates compared with chemotherapy alone. Survival benefits were consistent across subgroups, with no new safety signals observed.
• Clinical Relevance: These findings reinforce adebrelimab plus chemotherapy as a standard first-line treatment option for ES-SCLC. Durable survival benefit highlights the importance of immunotherapy in this setting.

Updated results from the phase 3 CAPSTONE-1 trial demonstrate that adebrelimab plus chemotherapy continues to provide durable survival benefit compared with chemotherapy alone in patients with extensive-stage small cell lung cancer (ES-SCLC).

These results were presented at the 2026 European Lung Cancer Congress in Copenhagen, Denmark, by Jie Wang, MD, Beijing Cancer Hospital, Beijing, China. 

In this study, 462 previously untreated patients were randomized 1:1 to receive either 20 mg/kg of adebrelimab once every 3 weeks plus chemotherapy (carboplatin and etoposide) for 4 to 6 cycles followed by maintenance adebrelimab (n = 230) or placebo plus chemotherapy followed by maintenance placebo (n = 232) for up to 2 years. The primary endpoint was overall survival (OS). 

At analysis, median OS was 15.3 months in the adebrelimab arm and 12.8 months in the placebo arm (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.60 to 0.89; P = .0008). OS rates were 16.2% and 7.7% at 48 months, 14.9% and 6% at 60 months, and 13.1% and 5.1% at 72 months. Among patients who completed 2 years of adebrelimab (n = 20), 100% achieved objective response. No new safety signals were observed. 

“After extended follow-up, adebrelimab [plus] chemo continued to provide clinically meaningful survival benefits vs placebo [plus] chemo, with a manageable safety profile, further reinforcing this regimen as a standard first-line therapy for ES-SCLC,” concluded Dr Wang et al. 

Source: 

Wang J, Liu H, Zhou C, et al. Adebrelimab plus chemotherapy (chemo) as first-line treatment for extensive-stage small cell lung cancer (ES-SCLC): 5-year update of the phase III CAPSTONE-1 study. Presented at European Lung Cancer Congress. March 25 - 28, 2026. Copenhagen, Denmark. 418P.