Trilaciclib Prior to Chemotherapy Plus Tislelizumab as 1L Treatment for Advanced Squamous Non-Small-Cell Lung Cancer

Inclusion Criteria:

* 1\. Age ≥ 18 years old and ≤ 75 years old, male or female;
* 2\. Unresectable stage ⅢB and Ⅳ squamous non-small cell lung cancer confirmed by histology or cytology;
* 3\. Have not received systemic anti-tumor therapy for advanced tumors in the past;
* 4\. There is at least one measurable lesion that meets the RECIST1.1 criteria;
* 5\. Patients with asymptomatic brain metastases or stable symptoms after treatment of brain metastases;
* 6\. Laboratory tests meet the following criteria: Hemoglobin ≥ 100 G/L (female), 110 G/L (male) Neutrophil count ≥ 2 × 10\^9/L Platelet count ≥ 100 × 10\^9/L; Creatinine ≤ 15 mg/L or creatinine clearance (CrCl) ≥ 60 mL/min (Cockcroft-Gault formula); Total bilirubin ≤ 1.5 × upper limit of normal (ULN); ALT and AST ≤ 3 × ULN or ≤ 5 × ULN (for patients with liver metastases); Albumin ≥ 30g/L;
* 7.ECOG PS score 0-1;
* 8\. Expected survival time ≥ 3 months;
* 9\. Women: All women with potential fertility must have negative serum pregnancy test results during the screening period, and must take reliable contraceptive measures from the signing of informed consent to 3 months after the last administration;
* 10\. Understand and sign the informed consent form.

Exclusion Criteria:

* 1\. Patients with the following diseases: Known HIV infection, active hepatitis B (defined as HBV DNA positive) and hepatitis C (HCV RNA positive); Interstitial lung disease/lung inflammation; Active, suspected autoimmune disease requiring systemic treatment in the past 2 years;
* 2\. Vaccination of live attenuated vaccine within 4 weeks before enrollment, or expected to require vaccination of live attenuated vaccine during the study period;
* 3\. Uncontrolled ischemic heart disease or clinically significant congestive heart failure (NYHA class III or IV);
* 4\. Stroke or cardiovascular and cerebrovascular events within 6 months before enrollment 5. QTcF \> 480 msec at screening and \> 500 msec for patients with ventricular pacemakers
* 6\. Previous hematopoietic stem cell or bone marrow transplantation
* 7.Hypersensitivity to the study drug or its components;
* 8\. Those who are not considered suitable to participate in the study by the investigator.