A Phase II Study of QL1706 With Anti-angiogenesis Therapy and Chemotherapy in Extensive-stage Small Cell Lung Cancer.

Prior treatment

• Prior chemotherapy, immunotherapy, targeted therapy, or radiotherapy.
• Concomitant condition requiring systemic corticosteroids or other immunosuppressive therapy.
• Participation in another investigational drug study within 4 weeks prior to randomization.
• Use of anti-tumor traditional Chinese medicine within 2 weeks prior to first study dose.
• Live vaccination within 28 days before randomization or planned during the study.
• Major surgery or significant trauma within 4 weeks prior to treatment initiation.

Other illness

• Symptomatic brain metastases or leptomeningeal disease.
• Active or suspected autoimmune disease, except for stable vitiligo, type 1 diabetes, hypothyroidism requiring only hormone replacement, or conditions not expected to recur.
• Evidence or history of active pulmonary tuberculosis (TB), including treated TB within the past year.
• Symptomatic interstitial lung disease or suspected drug-related pneumonitis.
• Positive for HIV antibodies, active HBV (HBsAg+ with HBV DNA \>10³ copies/mL), or active HCV infection (HCV-Ab+ with detectable RNA).
• History of significant neurological or psychiatric disorders (e.g., dementia, depression, epilepsy, bipolar disorder).
• History of other malignancies within 2 years, except for cured non-melanoma skin cancers or certain in situ carcinomas.
• Clinically significant cardiovascular or cerebrovascular disease (e.g., NYHA class ≥2 heart failure, recent myocardial infarction or stroke within 6 months).
• History of thromboembolic events (e.g., DVT, PE, arterial thrombosis) within 6 months, except catheter-related thrombosis.
• Conditions affecting drug absorption (e.g., severe vomiting, GI obstruction, active GI bleeding or perforation).
• Active, uncontrolled bacterial, viral, or fungal infections despite appropriate treatment.
• Known hypersensitivity to any study drug or excipients.
• Any other condition deemed unsuitable by the investigator due to safety or compliance concerns.

Other

• Histologic or cytologic evidence of non-small cell or mixed small cell/non-small cell carcinoma.
• Pregnant or breastfeeding females.

• Participants must meet all of the following criteria to be eligible for the study:
• Signed written informed consent and willingness to comply with study procedures.
• Age ≥18 years.
• Estimated life expectancy ≥3 months.
• ECOG performance status of 0 or 1.
• 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.
• Fully understands and voluntarily participates in the study.
• Adequate organ function as defined below:
  • Absolute neutrophil count ≥1.5 × 10⁹/L
  • Platelets ≥100 × 10⁹/L
  • Hemoglobin ≥90 g/L (without transfusion in prior 14 days)
  • Serum creatinine ≤1× ULN or creatinine clearance \>50 mL/min (Cockcroft-Gault)
  • AST and ALT ≤2.5× ULN (≤5× ULN with liver metastases)
  • Total bilirubin ≤1.5× ULN (except Gilbert's syndrome \<51.3 µmol/L)
  • TSH, FT3, FT4 within ±10% of normal limits