Extensive Small Cell Lung Cancer

This single-arm, open-label, Phase II study assesses first-line QL1706 + bevacizumab (anti-VEGF) + platinum/etoposide chemotherapy to treat naïve ES-SCLC patients.The main questions it aims to answer are: Evaluate efficacy and safety of this quadruplet regimen in ES-SCLC Explore correlations between tumor biomarkers and treatment efficacy Participants will: Histologically or cytologically confirmed, treatment-naïve extensive-stage small cell lung cancer (ES-SCLC). Willing to provide archived or fresh tumor tissue samples. If unavailable, enrollment may proceed per investigator assessment. At least one measurable lesion per RECIST v1.1

To observe the efficacy and safety of adebelizumab combined with chemotherapy and sequential adebelizumab combined with radiotherapy in the treatment of newly diagnosed extensive small cell lung cancer.