Inclusion Criteria:
* Capable of comprehending the nature of the study and voluntarily signing the Informed Consent Form (ICF).
* Aged ≥18 and ≤75 years, regardless of gender.
* Patients with driver gene-negative NSCLC who have failed first-line standard therapy and are ineligible for second-line therapy or alternative chemotherapy regimens.
* Treatment failure definition: Disease progression during or after treatment. Changes in therapy due to drug intolerance are not considered treatment failure.
* At least one measurable tumor lesion per RECIST v1.1.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
* Investigator-assessed life expectancy ≥3 months.
* Agreement to undergo tumor tissue biopsy prior to initial study treatment and during therapy when clinically feasible.
* Adequate organ function confirmed by laboratory tests within 7 days prior to first dose:
Bone marrow function (no transfusion/growth factors within 2 weeks pre-screening):
Absolute neutrophil count ≥1.5×10⁹/L;Platelet count ≥75×10⁹/L;Hemoglobin ≥90 g/L Hepatic function:Total bilirubin ≤1.5×ULN (≤3×ULN with liver metastases); AST/ALT ≤2.5×ULN (≤5×ULN with liver metastases);Albumin ≥28 g/L Renal function:Serum creatinine ≤1.5×ULN OR creatinine clearance ≥50 mL/min. Coagulation:INR and APTT ≤1.5×ULN. Chronic HBV-infected subjects must have HBV-DNA \<1,000 IU/mL and commit to antiviral therapy throughout the study.
* Prior treatment-related toxicities resolved to ≤Grade 1 (CTCAE v5.0) or stabilized (excluding alopecia/pigmentation).
* Subjects of reproductive potential must use highly effective contraception from ICF signing until 6 months post-last dose.
* Ability to communicate effectively with investigators and comply with protocol-specified follow-up.
Exclusion Criteria:
* Received cytotoxic chemotherapy or Chinese herbal medicines with antitumor activity within 14 days prior to the first dose.
* Received radiotherapy, biologic therapy (e.g., cancer vaccines, cytokines, growth factors), or other immunotherapy (excluding PD-1/PD-L1 inhibitors) within 28 days or 5 half-lives (whichever is shorter) before the first dose.
Note: For palliative radiotherapy (≤14 days total duration) targeting non-CNS lesions, a ≥7-day washout period is required prior to the first dose.
* Received anti-interleukin-4 receptor alpha (IL-4Rα) monoclonal antibodies, anti-IgE monoclonal antibodies, or other biologics within 10 weeks or 5 half-lives (whichever is longer) before the first dose.
* Received live/attenuated vaccines within 12 weeks prior to the first dose or plans to receive such vaccines during the study.
* History of hypersensitivity to anti-IL-4Rα monoclonal antibodies, Stapokibart Injection, or other protein-based therapeutics (e.g., vaccines, immunoglobulins).
* Grade ≥3, severe, or life-threatening immune-related adverse events (irAEs) during prior immunotherapy (excluding Grade 3 endocrine AEs manageable with replacement therapy), or unresolved Grade 1-2 irAEs after treatment discontinuation.
* Clinically significant cardiovascular/cerebrovascular diseases, including:
Major events (e.g., congestive heart failure, acute MI, unstable angina, stroke, TIA, DVT/PE) within 6 months before the first dose.
* QTcF \>480 msec.
* LVEF \<50% by echocardiography.
* NYHA Class ≥2.
* Uncontrolled hypertension (SBP ≥160 mmHg or DBP ≥100 mmHg; rescreening permitted if controlled post-intervention).
* Other cardiovascular conditions deemed high-risk by investigators.
* Planned major surgery during the study period.
* Active CNS metastases. Note: Treated brain metastases may be eligible if radiographically/ clinically stable for ≥14 days before the first dose, confirmed by repeat imaging (≥4-week interval) during screening.
* Uncontrolled pleural, peritoneal, or pericardial effusion (investigator-assessed).
* Active Mycobacterium tuberculosis infection (i.e., active tuberculosis).
* HCV Ab-positive with detectable HCV RNA.
* HIV infection or positive HIV antibody test during screening.
* History of other malignancies within 5 years (exceptions: cured basal/squamous cell carcinoma, cervical/breast ductal carcinoma in situ).
* Active autoimmune disease requiring systemic treatment (e.g., immunomodulators, corticosteroids) within 2 years.
Note: Replacement therapy (e.g., thyroxine, insulin) is permitted.
* Prior organ or allogeneic hematopoietic stem cell transplantation.
* Pregnancy or lactation.
* Any condition that may confound study results, impair compliance, or jeopardize subject safety (investigator-determined).
