TQB6411 injection for advanced lung cancer.

Inclusion Criteria:

* Participants voluntarily participate in this study, sign the informed consent form, and demonstrate good compliance;
* Age between 18 and 75 years (calculated based on the date of signing the informed consent form);
* Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1;
* Expected survival greater than 12 weeks;
* At least one measurable lesion according to RECIST v1.1 criteria;
* Laboratory test results meeting the following criteria (no blood transfusion within 14 days or hematopoietic growth factor administration within 7 days prior to screening):

  1. Hemoglobin (HGB) ≥ 90 g/L;
  2. Absolute neutrophil count (NEUT) ≥ 1.5×10⁹/L;
  3. Platelet count (PLT) ≥ 90×10⁹/L;
  4. Total bilirubin (TBIL) ≤ 1.5×Upper Limit of Normal (ULN);
  5. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5×ULN (≤ 5×ULN if liver metastases are present);
  6. Serum creatinine (CR) ≤ 1.3×ULN or creatinine clearance rate (CCR) ≥ 50 mL/min;
  7. Prothrombin time (PT), activated partial thromboplastin time (APTT), and international normalized ratio (INR) ≤ 1.5×ULN (no anticoagulant therapy within the past 2 weeks);
* Lung cancer confirmed by histology or cytology；
* Willing to provide qualified tumor tissue samples for immunohistochemical and amplification testing, unless the participant has no eligible archived specimens and is unsuitable or refuses re-biopsy;
* Women of childbearing potential must agree to use effective contraception during the study and for 6 months after study completion, with a negative serum or urine pregnancy test within 7 days before enrollment; male participants must agree to use effective contraception during the study and for 6 months after study completion (see Section 5.5 for details).

Exclusion Criteria:

* History of or concurrent other malignancies, except for: other malignancies treated with surgery alone and achieving ≥5 years of disease-free survival (DFS); or cured carcinoma in situ of cervix, non-melanoma skin cancer, or superficial bladder tumors \[Ta (non-invasive tumor), Tis (carcinoma in situ), and T1 (tumor invading basement membrane)\].
* Diseases affecting intravenous injection or blood sampling.
* Adverse reactions from prior therapies not recovered to Common Terminology Criteria for Adverse Events (CTCAE) v6.0 grade ≤1, except for: grade 2 alopecia, grade 2 peripheral neuropathy, grade 2 anemia, non-clinically significant asymptomatic grade 2 laboratory abnormalities, hypothyroidism stabilized with hormone replacement, or other toxicities judged by investigator as non-safety risks.
* Major surgery (Grade 3 or above per National Surgical Classification Catalog 2022), significant traumatic injury within 4 weeks prior to first dose, planned major surgery during study (except protocol-specified procedures), or presence of unhealed wounds/fractures.
* Any bleeding or hemorrhagic events ≥CTCAE grade 3 within 4 weeks prior to first dose.
* Arterial/venous thromboembolic events within 6 months prior to first dose, including: cerebrovascular accidents (including transient ischemic attack (TIA), excluding lacunar infarction), deep vein thrombosis, or pulmonary embolism (implantable venous port- or catheter-related thrombosis or superficial venous thrombosis not considered "severe" thromboembolism).
* Active viral hepatitis with poor control, except: hepatitis B surface antigen (HBsAg)-positive participants with HepatitisBvirus Deoxyribonucleic acid (HBV DNA) \<500 IU/mL (2500 copies/mL) who agree to receive anti-HBV therapy throughout study; or hepatitis C virus (HCV)-infected participants (Hepatitis C Virus Antibody or Ribonucleic Acid positive) with hepatitis C virus Ribonucleic Acid (HCV RNA) ≤ULN continuing approved antiviral therapy.
* Active syphilis requiring treatment.
* Active tuberculosis, history of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced/radiation pneumonitis requiring treatment, clinically significant active pneumonia, history of interstitial lung disease (ILD) requiring treatment, or current ILD.
* History of psychotropic drug abuse or mental disorders.
* Prior or planned allogeneic bone marrow or solid organ transplantation.
* History of hepatic encephalopathy.
* Significant cardiovascular diseases including:

  1. Cardiac dysfunction ≥New York Heart Association (NYHA) class II or Left Ventricular Ejection Fractions (LVEF) \<50% by echocardiography;
  2. Clinically significant ventricular arrhythmia history (e.g., sustained ventricular tachycardia, ventricular fibrillation, torsades de pointes) or arrhythmias requiring continuous antiarrhythmic therapy (participants with stable atrial fibrillation controlled solely by β-blockers may be included after investigator assessment);
  3. Unstable angina;
  4. Myocardial infarction within 12 months;
  5. Cardio contraction time (QTc) \>450ms (male) or \>470ms (female) (if abnormal, measure three times at ≥2-minute intervals and average; corrected by Fridericia or Bazett method);
  6. Congenital long QT syndrome or family history.
* Active or uncontrolled severe infection (≥CTCAE grade 2).
* Renal failure requiring hemodialysis or peritoneal dialysis.
* Immunodeficiency including HIV positivity or other acquired/congenital immunodeficiency diseases.
* Uncontrolled autoimmune diseases requiring immunosuppressants or systemic corticosteroids (\>10mg prednisone/day equivalent) within 7 days prior to first dose.
* Epilepsy requiring treatment.
* Poorly controlled diabetes (fasting blood glucose \>10mmol/L).
* Tumor-related conditions and treatments:

  1. Chemotherapy, immunotherapy, or small-molecule targeted therapy within 3 weeks prior to first dose or within 5 half-lives (whichever shorter); prior local radiotherapy allowed if: completed \>4 weeks (\>2 weeks for brain) before study treatment, and target lesions are outside radiation field or show progression within field;
  2. National Medical Products Administration (NMPA)-approved traditional Chinese medicines with antitumor indications within 1 week prior to first dose;
  3. Tumor invading major vessels or judged likely to cause fatal hemorrhage;
  4. Uncontrolled effusions/ascites requiring recurrent drainage;
  5. Spinal cord compression, leptomeningeal metastases, or brain metastases with symptoms controlled \<4 weeks, or requiring steroids/dehydrating agents within 2 weeks before treatment.
* Known hypersensitivity to study drug or excipients.
* Prior treatment with: Epidermal Growth Factor Receptor/cellular-mesenchymal epithelial transition factor (EGFR/c-Met)-targeted antibody-drug conjugates (ADCs); or topoisomerase I inhibitors (Non-Small Cell Lung Cancer only) or topoisomerase I inhibitor-based ADCs.
* Prior EGFR/c-Met-targeted Monoclonal Antibody (mAbs)/bispecifics with: ≥grade 4 toxicity, permanent discontinuation due to toxicity, ≥grade 3 infusion reactions, or ≥grade 3 myalgia.
* Participation in other antitumor clinical trials within 4 weeks prior to first dose.
* Other conditions judged by investigator to jeopardize participant safety or study completion.