Precise Treatment for BLIS Subtype of TNBC in the First-line Treatment of Locally Advanced or Metastatic Breast Cancer

Inclusion Criteria:

* ECOG Performance Status of 0-1
* Expected lifetime of not less than three months
* Metastatic or locally advanced, histologically documented TNBC (absence of HER2, ER, and PR expression) with BLIS subtype
* Cancer stage: recurrent or metastatic breast cancer; Local recurrence be confirmed by the researchers could not be radical resection
* Patients had received no previous chemotherapy or targeted therapy for metastatic triple-negative breast cancer
* At least one measurable or non-measurable lesion according to Response Evaluation Criteria in Solid Tumors v1.1 (RECIST v1.1), which didn't receive radiation therapy
* The functions of major organs are basically normal
* For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures as outlined for each specific treatment arm
* Have the cognitive ability to understand the protocol and be willing to participate and to be followed up

Exclusion Criteria:

* Symptomatic, untreated, or actively progressing CNS metastases
* Significant cardiovascular disease
* Adverse reactions of Grade ≥1 that are still continuing due to previous treatments. Exceptions are those of hair loss or which researchers take it as exception
* Major surgery was performed within 3 weeks of the first course of trial treatment (except for minor outpatient surgery, such as placement of vascular access)
* Pregnancy or breastfeeding, or intention of becoming pregnant during the study
* Other malignancies within 5 years, excluding cured cervical carcinoma in situ, skin basal cell carcinoma, or skin squamous cell carcinoma
* Inability to swallow, chronic diarrhea and intestinal obstruction, there are multiple factors that affect the use and absorption of drugs
* Presence of third-space fluid accumulation that cannot be controlled by drainage or other methods (such as excessive pleural fluid and ascites)
* Participated in clinical trials of other antitumor drugs within 4 weeks before first taking the investigational drug
* Long-term unhealing wound or incomplete healing of fracture
* Patients with known active HBV or HCV infection or hepatitis B DNA≥500, or chronic phase with abnormal liver function
* Allergic constitution, or known allergic history of the drug components of this trial; Or allergic to other monoclonal antibodies
* Patients with a history of gastrointestinal bleeding or a clear tendency to gastrointestinal bleeding within the past 6 months, such as esophageal varicose veins with bleeding risk, locally active ulcer lesions, stool occult blood ≥ (++), were not allowed to enter the group; If there is occult blood in the stool (+), gastroscopy is required
* Abdominal fistula, gastrointestinal perforation or abdominal abscess occurred within 28 days before participating in this trial
* Urine protein ≥2+ and 24h urine protein quantitative \> 1.0 g
* Patients suffering from hypertension and unable to reach the normal range after antihypertensive drug treatment (systolic blood pressure \>140mmHg, diastolic blood pressure \>90mmHg)