A Study of QL1706 Combined With Chemotherapy Induction on Sequential Immunotherapy Consolidation in Patients With Limited-Stage Small Cell Lung Cancer After Chemoradiotherapy

"Induction: QL1706 5 mg/kg IV on Day 1, Etoposide: 100 mg/m² IV on Days 1-3, Cisplatin or Carboplatin: Cisplatin 75 mg/m² IV on Day 1 or Cisplatin 25 mg/m² IV on Days 1-3, Or Carboplatin AUC = 5 IV on Day 1, Q3W, for a total of 2 cycles.~Chemoradiotherapy：Thoracic Radiotherapy（60 Gy in 30 fractions, once daily (2 Gy/fraction), or 45 Gy in 30 fractions, twice daily (1.5 Gy/fraction)），Etoposide 100 mg/m² IV on Days 1-3, Cisplatin either 75 mg/m² IV on Day 1, or 25 mg/m² IV on Days 1-3, Or Carboplatin AUC=5 IV on Day 1 PCI: Patients achieving or approaching complete response, per investigator assessment, 25Gy in 10 fractions.~Consolidation: QL1706 5 mg/kg IV on Day 1, Q3W"