Local Consolidative Therapy Versus Maintenance Immunotherapy After First-Line Chemoimmunotherapy in Metastatic NSCLC

Inclusion Criteria:

1. Voluntary participation in the study with signed informed consent;
2. Age ≥18 years, both male and female;
3. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1;
4. Estimated life expectancy ≥12 months;
5. Histologically/cytologically confirmed non-small cell lung cancer (NSCLC) at initial diagnosis, with TNM stage IV (IASLC 9th edition);
6. Absence of actionable genetic mutations related to EGFR/ALK/ROS1 and other druggable targets;
7. Completion of 4-6 cycles of immunotherapy (PD-1/PD-L1 monoclonal antibody) combined with platinum-based doublet chemotherapy prior to enrollment;
8. Achievement of partial response (PR) or complete response (CR) as assessed by RECIST 1.1 criteria;
9. Presence of metabolically active residual lesions on PET evaluation, and clinical assessment by the multidisciplinary team (MDT)\* indicating feasibility of individualized local therapy (e.g., ≤3 organs and ≤5 lesions, amenable to surgery/radiotherapy/ablation);
10. Adequate organ function.

Exclusion Criteria:

1. Expected to be unable to tolerate surgery, radiation therapy, or ablation;
2. Unable to receive local treatment for all active residual lesions;
3. Patients with a confirmed history of malignant pleural effusion or pleural dissemination;
4. Pathologically diagnosed with neuroendocrine cancer at initial diagnosis (including small cell lung cancer, combined small cell lung cancer, large cell neuroendocrine carcinoma, mixed large cell neuroendocrine carcinoma, and carcinoid). Patients who do not show neuroendocrine components at initial diagnosis but develop such components in post-surgical pathology may be included;
5. Previously received allogeneic tissue or solid organ transplantation;
6. History of interstitial lung disease requiring steroid treatment (non-infectious) or currently suffering from interstitial lung disease requiring steroid treatment;
7. Presence of viral infectious diseases during screening:

   1. Positive serum test for human immunodeficiency virus (HIV);
   2. Active hepatitis B: positive hepatitis B surface antigen (HBsAg) and HBV-DNA quantitative test \>500 IU/mL or \>2000 copies/mL;
   3. Active hepatitis C: positive hepatitis C virus (HCV) antibody and HCV-RNA quantitative test above the upper limit of normal;
8. Participants with uncontrolled hypertension defined as systolic blood pressure \>150 mmHg or diastolic blood pressure \>90 mmHg (adjustment of antihypertensive medications is allowed prior to study initiation, but the average of the most recent three consecutive blood pressure readings before enrollment must be ≤150/90 mmHg) (each measurement separated by at least 2 minutes);
9. Active infection requiring intravenous antimicrobial therapy at screening;
10. Diagnosis of another malignancy within 3 years prior to signing informed consent, excluding cured cases of cutaneous basal cell carcinoma, cervical or breast in situ carcinoma, superficial bladder cancer, localized prostate cancer; participants with low-risk early-stage prostate cancer (T1-T2a stage, Gleason score ≤6, PSA \<10 ng/mL) are eligible if they have undergone curative treatment or are under active surveillance with stable disease, regardless of whether they have received treatment;
11. Conditions that may interfere with interpretation of study results or affect the participant's ability to complete the entire study, or where, in the investigator's judgment, participation does not serve the participant's best interest;
12. Pregnant, breastfeeding, or planning pregnancy; positive pregnancy test within 7 days prior to first study treatment;
13. Poor compliance, unwillingness or inability to follow the study procedures as required.