This study aims to evaluate the efficacy and safety of adebrelimab consolidation therapy after progression-free response of concurrent chemoradiotherapy in patients with limited-stage small cell lung cancer. This study plans to enroll patients with untreated limited-stage small cell lung cancer who meet the inclusion criteria. The eligible patients will be randomly divided 1:1 into two groups to receive treatment regimens for residual lymph nodes and involved irradiated areas. That is, carboplatin AUC 5, D1 + etoposide 100 mg/m…\^2 on days 1, 2, and 3 + thoracic radiotherapy (residual lymph nodes or involved irradiated areas), with each 3-week cycle.After 4 cycles of concurrent chemoradiotherapy, the non-progressing subjects will continue to receive adebrelimab (1200 mg, IV, Q3W) maintenance therapy.
Hematology: Absolute neutrophil count (ANC) ≥ 1.5×10⁹/L without G-CSF support within 14 days before first treatment; lymphocyte count (LC) ≥ 0.5×10⁹/L; platelet count (PLT) ≥ 90×10⁹/L without transfusion, G-CSF, or other hematopoietic stimulants within 14 days before first treatment.
Hepatic function: Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 3 × ULN; total bilirubin (TBIL) ≤ 1.5 × ULN (≤3.0 mg/dL for patients with confirmed Gilbert syndrome).
Renal function: Serum creatinine ≤ 1.5 × ULN or creatinine clearance (CrCl) ≥ 50 mL/min (calculated by Cockcroft-Gault, CKD-EPI, or MDRD equation); urine protein < 2+ (if urine protein ≥ 2+, 24-hour urine protein must be < 1 g for eligibility).
Coagulation: International normalized ratio (INR) ≤ 1.5; activated partial thromboplastin time (APTT) ≤ 1.5 × ULN.
Histologically confirmed combined small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC).
Prior systemic anti-tumor therapy or immune checkpoint inhibitor therapy for SCLC.
Extensive-stage SCLC.
Presence of malignant pleural effusion. If aspiratable pleural effusion is present during screening, at least one thoracentesis must be performed to confirm the presence or absence of malignant cells.