To evaluate the efficacy of metronomic chemotherapy combination with tislelizumab in EGFR/ALK-negative advanced NSCLC patients intolerant to first-line standard chemotherapy.

This study is a clinical intervention study. The patients who comfirm the criteria will be treated with tislelizumab plus metronomic oral vinorelbine. The patients will be followed up until the tumor progressed, and the efficacy (PFS, ORR, DCR) of tumor therapy were evaluated. Drug administration regimen: tislelizumab 200mg intravenous drip once every 3 week3; Oral Vinorelbine 40mg three times a week for three weeks and Q28d for one course.

Inclusion Criteria:

• Has a histologically or cytologically confirmed diagnosis of stage IV (M1a or M1b-American Joint Committee on Cancer [AJCC] 8th edition) squamous NSCLC or non-squamous NSCLC without sensitising EGFR or ALK alterations.
• Has measurable disease based on RECIST 1.1 as determined by the local site investigator/radiology assessment.
• Has not received prior systemic treatment for metastatic NSCLC.
• Has a life expectancy of at least 3 months.
• Has fully understood this study and voluntarily signed a written informed consent form.
• Deemed unsuitable by the investigator for any platinum-doublet chemotherapy due to poor performance status (ECOG performance status of 2-3)；>= 75 years of age；substantial comorbidities; contraindication(s) for any platinum-doublet chemotherapy.

Exclusion Criteria:

• Histological or cytological confirmation of small cell lung cancer.
• Has a known history of prior malignancy except if the participant has undergone potentially curative therapy with no evidence of that disease recurrence for 5 years since initiation of that therapy.
• Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis.
• Has disorders of oral medication.