Case Report: Long-term survival in extensive-stage small cell lung cancer treated with adebrelimab-based combination therapy.

The integration of immune checkpoint inhibitors into first-line treatment has markedly improved outcomes for extensive-stage small cell lung cancer (ES-SCLC). Adebrelimab, a PD-L1 inhibitor, demonstrated superior overall survival in the phase 3 CAPSTONE-1 trial. We present a detailed case of a 62-year-old male with ES-SCLC who achieved a progression-free survival (PFS) of 33 months following a multimodal regimen of adebrelimab plus chemotherapy, consolidative thoracic radiotherapy, and maintenance immunotherapy. Despite low PD-L1 expression (TPS<1%), the patient exhibited profound and durable tumor regression, with the primary mass shrinking from 146×158×217 mm to 51×21 mm. Treatment was well-tolerated with only grade 1-2 adverse events. This report underscores the potential for long-term disease control with adebrelimab-based therapy even in biomarker-unselected populations and highlights the importance of combined modality strategies.