Trilaciclib Combined With Anti-PD-1 Antibody and Chemotherapy in the Treatment of Locally Advanced TNBC

Inclusion Criteria: 1. Patients fully understand and voluntarily participate in this study and sign the informed consent form. 2. Age ≥18 and ≤75 years. 3. Newly diagnosed TNBC with stage T1c N1-3 or stage T2-4 N0-3. 4. Patients scheduled to receive neoadjuvant therapy. 5. Patients have measurable lesions (non-lymph node lesions ≥10 mm in length and lymph node lesions ≥15 mm in length according to RECIST 1.1 standards). 6. No previous antitumor system therapy. 7. ECOG (Eastern Cooperative Oncology Group) performance status of 0-1. 8. Patients voluntarily joined the study with nice compliance. 9. Good organ function (no blood transfusion or growth factor support within 2 weeks before the first dose of trial medication): WBC≥3.0×10\^9/L, ANC ≥1.5×10\^9/L, PLT ≥75×10\^9/L, Hb≥90g/L, ALP≤5×ULN, ALT≤3×ULN, AST≤3×ULN, ALB≥28 g/L, Creatinine≤1.5×ULN or Creatinine clearance ≥50 mL/min, INR≤1.5 /PT≤1.5×ULN, aPTT≤1.5×ULN (If patient is receiving anticoagulant therapy, as long as the PT INR is within the prescribed range of anticoagulants). Exclusion Criteria: 1. Pathological diagnosis of HR+ or HER2+ breast cancer. 2. Imaging shows metastatic breast cancer. 3. Previous or current concurrent malignancy other than breast cancer. 4. Patients had any active autoimmune disease or a history of autoimmune disease (e.g., but not limited to autoimmune hepatitis, interstitial pneumonia, uveitis, enteritis, hepatitis, pituitary vasculitis, nephritis, hyperthyroidism; Patients had vitiligo; Patients who had complete remission of asthma in childhood and without any intervention in adulthood were included; Patients with asthma requiring medical intervention with bronchodilators were not included). 5. Patients are taking immunosuppressants or systemic hormone therapy for immunosuppressive purposes (dose \> 10mg/day of prednisone or other therapeutic hormone) and continued use within 2 weeks prior to enrollment. 6. Recurrence after surgery, previous local or systemic antitumor therapy. 7. Patients are known to have a prior allergy to the drug ingredient being applied. 8. Patients with poorly controlled cardiac clinical symptoms or diseases, such as (1)NYHA2 or higher heart failure, (2) unstable angina pectoris, (3) myocardial infarction within 1 year, (4) Clinically significant supraventricular or ventricular arrhythmias requiring treatment or intervention. 9. Patients with active infection or unexplained fever during screening or prior to initial treatment \>38.5℃ (as determined by the investigator, the subject's fever due to the tumor can be enrolled). 10. Live vaccine was administered less than 4 weeks before or possibly during the study period 11. Patients have a known history of psychotropic substance abuse, alcohol abuse, or druggy use. 12. Patients should be excluded if, in the investigator's judgment, the subjects have other factors that may cause the study to be terminated (other severe medical conditions requiring concomitant treatment, serious laboratory abnormalities, associated family or social factors, and other circumstances that may affect the safety of the subjects or the collection of data and samples).