Efficacy and Safety of Vorolanib Monotherapy As Third-line or Later Treatment for Advanced Non-small Cell Lung Cancer Patients: a Single-arm, Prospective, Open-label Phase II Clinical Study

Inclusion Criteria: 1. Sign the informed consent 2. Pathologically or cytologically diagnosed with metastatic/relapsed advanced NSCLC, with measurable lesions (according to RECIST 1.1) 3. Previously received at least two systemic therapies, allowing for third-line or higher chemotherapy or unable to tolerate chemotherapy 4. Patients with negative results for driver gene testing or patients with positive results who have already received relevant targeted drugs or systemic anti-tumor treatments and are either resistant or unable to tolerate them 5. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2. Expected survival time ≥ 3 months 6. Normal major organ function: renal function with creatinine clearance rate ≥ 60 mL/min; liver function with bilirubin ≤ 1.5× upper limit of normal (ULN), ALT/AST ≤ 2.5× ULN (for patients with documented liver metastasis, AST and ALT levels ≤ 5× ULN) 7. Good hematological function, defined as an absolute neutrophil count (ANC) ≥ 1.5×10\^9/L, platelet count ≥ 100×10\^9/L, hemoglobin ≥ 90g/L (without blood transfusion or erythropoietin \[EPO\] dependency within the last 7 days) 8. Good coagulation function, defined as an international normalized ratio (INR) or prothrombin time (PT) ≤ 1.5× ULN; if the subject is on anticoagulation therapy, PT should be within the intended therapeutic range of the anticoagulant 9. Female patients of childbearing potential must agree to use contraception (e.g., intrauterine device, contraceptives, or condoms) during the study and for 6 months after the study ends; must not be breastfeeding and must have a negative serum or urine pregnancy test within 7 days before enrollment. Male patients must agree to use contraception during the study and for 6 months after the study ends 10. Patients with well-controlled pleural or peritoneal effusions that do not cause grade 2 or higher respiratory syndrome (≥ CTCAE grade 2) can be included 11. Patients without clinical symptoms of intracranial hypertension caused by brain metastases or with brain metastasis symptoms that are stable after prior treatment (radiation therapy or surgery) of brain or meningeal metastasis (usually requiring more than 4 weeks post-radiation therapy) Exclusion Criteria: 1. Previously failed treatment with multi-target anti-angiogenic drugs, such as anlotinib, cabozantinib, apatinib, lenvatinib, etc. The use of bevacizumab is allowed, but the last administration must be more than 3 weeks before enrollment 2. Small cell lung cancer (including small cell carcinoma, non-small cell lung cancer mixed with other types of tumors) 3. Testing positive for driver genes but not treated with TKIs 4. Tumor invasion of large blood vessels, central squamous cell carcinoma of the lung with cavitation, or non-small cell lung cancer with hemoptysis (\>5ml/day), or where the tumor is likely to invade important blood vessels and cause fatal bleeding during the subsequent study period 5. Accompanied by other types of malignant tumors within the past 5 years or currently 6. Planning to receive systemic anti-tumor therapy within 4 weeks before enrollment or during the study period, including cytotoxic therapy, signal transduction inhibitors, and immunotherapy (or mitomycin C within 6 weeks before receiving experimental drug therapy); received extended-field radiation therapy (EF-RT) within 4 weeks before enrollment or limited-field radiation therapy within 2 weeks before enrollment with evaluation of lesions recommended 7. Unremitting toxic reactions caused by previous treatment, CTCAE grade \>1, excluding hair loss 8. Various factors affecting oral medication (such as inability to swallow, gastrointestinal resection, chronic diarrhea, bowel obstruction) 9. Pleural effusion or ascites leading to respiratory syndrome (≥CTCAE grade 2) 10. Symptoms of brain metastasis not controlled and treated within 2 months 11. Presence of any severe or uncontrolled disease 12. Major surgery, open biopsy, or significant traumatic injury within 28 days before enrollment 13. Bleeding diathesis or history of significant bleeding, regardless of severity; any wound, ulcer, or fracture that has not healed following a bleeding or bleeding event (≥CTCAE grade 3) 14. Arterial/venous thrombosis within 6 months, such as cerebrovascular accident (including transient ischemic attack), venous thrombosis, pulmonary embolism 15. History of substance abuse that cannot be quit or diagnosed with psychiatric disorders 16. Participated in other clinical trials of anti-tumor drugs within 4 weeks 17. Diagnosed with diseases that severely jeopardize patient safety or affect the completion of this study 18. Known history of human immunodeficiency virus (HIV) infection (i.e., HIV 1/2 antibody positive); untreated active hepatitis B; active HCV infection (HCV antibody positive and HCV-RNA levels above detection limit)