⁃ Patients voluntarily participated in the study, signed the informed consent, and had good compliance; Female patients aged 18-70; TNBC confirmed by histology or cytology. Triple negative is defined as \<1% expression of estrogen receptor (ER) and progesterone receptor (PR), and negative in situ hybridization expression of human epidermal growth factor receptor 2 (HER2). Unresectable locally advanced or metastatic TNBC failed or relapsed after treatment with at least one line of standard chemotherapy regimens (taxanes and/or anthracyclines); Patients should have at least one measurable lesion (RECIST 1.1); ECOG PS 0 or 1; Expected survival ≥12 weeks; Blood test (without blood transfusion within 14 days)

• Neutrophil absolute value ≥1.5×109/L, platelet ≥100×109/L, hemoglobin concentration ≥9g/dL);

• Liver function test (aspartate aminotransferase and glutamic aminotransferase ≤2.5×ULN, bilirubin ≤1.5×ULN; In the presence of liver metastasis, AST and ALT≤5×ULN);

• Renal function (serum creatinine ≤1.5×ULN, or creatinine clearance (CCr)≥60ml/min);

• Coagulation, International standardized ratio (INR) ≤1.5, prothrombin time (PT) and activated partial thrombin time (APTT) ≤1.5×ULN;

• Thyroid function, thyroid stimulating hormone (TSH) ≤ upper limit of normal (ULN); If abnormal, FT3 and FT4 levels should be examined, and normal FT3 and FT4 levels can be included. Women of reproductive age must undergo a negative serum pregnancy test within 14 days prior to treatment and be willing to use medically approved effective birth control (e.g., intrauterine devices, contraceptives or condoms) during the study period and within 3 months after the last study drug use.