Compare Apatinib Plus Capecitabine Versus Capecitabine in Maintenance Therapy for Patients With Advanced Triple-negative Breast Cancer

Inclusion Criteria:

1. Age：18\~75 years;
2. Triple-negative breast cancer (TNBC) confirmed by histology examination;
3. patients had received first-line combination chemotherapy for advanced metastatic disease, and had a complete response, partial response or stable disease according to Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria;
4. received endocrine therapy for metastatic disease before first-line chemotherapy were allowed;
5. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1;
6. A life expectancy of more than 12 weeks;
7. Baseline blood routine examination in accordance with the following criteria : ANC≥1.5×109/L，PLT≥90×109/L，Hb≥90g/L;
8. Liver and renal function in accordance with the following criteria: total bilirubin less than 1.5 times the upper limit of normal value; aspartate aminotransferase (AST), or alanine aminotransferase (ALT) less than 2.5 times the upper limit of normal value, less than 5 times the upper limit of normal value in patients with liver metastases.

   the creatinine clearance rate calculated greater than 60 mL/min;
9. Females of childbearing potential must be a pregnancy test in 7 days before participating ( including serum or urine), and the results were negative, and they are willing to take effective contraceptive methods During the trial and within 8 weeks after the last dose;
10. Obtain informed consent from patients before starting any research-related operations and treatments to confirm that patients are willing to participate in this study and comply with research-related requirements.

Exclusion Criteria:

1. Metastasis/recurrence occurs within 6 months of adjuvant chemotherapy;
2. controlled high blood pressure, systolic blood pressure ≥150mmHg or diastolic blood pressure ≥100mmHg;
3. urine routine test with urinary protein more than ++, or 24 hour urinary protein more than 1.0 g;
4. abnormal coagulation function (INR \> 1.5 or prothrombin time (PT) \> ULN+4 seconds or APTT \>1.5 times the ULN);
5. Pregnant or lactating woman;
6. Symptomatic brain parenchymal and/or pia mater metastases without treatment and control;
7. Patients with Other malignant tumors in the past 5 years, except for fully treated cervical carcinoma in situ, cutaneous squamous cell carcinoma or well-controlled localized basal cell skin cancer;
8. Mental illness or other condition that affects patient compliance;
9. serious and uncontrollable systemic diseases (eg clinically significant cardiovascular disease, lung or metabolic disease, arteriovenous thrombosis, etc.) happened recently;
10. Can not take or absorb oral drugs;
11. Receiving any other testing drugs, or participating in other clinical trial 30 days before being enrolled in this trial;
12. The patient has previously received treatment with an anti-angiogenic drug (whether adjuvant or palliative);
13. Known or suspected to be allergic to any research drug or excipient;
14. Any other researcher believes that it is not appropriate to participate in this test.