A Multicenter Clinical Study of Apatinib Mesylate Combined With Doctor's Choice for Advanced Breast Cancer

Inclusion Criteria：

1. Histologically or cytologically confirmed her-2 negative, HR-positive progressive breast cancer (prior chemotherapy (including adjuvant or neoadjuvant) with anthracycline and/or paclitaxel required);
2. No more than 3 lines of chemotherapy for recurrent or metastatic breast cancer;
3. Must have progression previously used endocrine therapy and CDK4/6 inhibitors for recurrent or metastatic disease ;
4. PET-CT（SUV）\>5;
5. Age ≥18 years;
6. ECOG PS 0-1;
7. life expectancy ≥ 3 months
8. Have at least one measurable lesion as a target lesion confirmed by CT or MRI according to RECIST version 1.1 criteria. If the target lesion is a lymph node require a short diameter greater than 1.5 ，and the target lesion is not amenable to surgical treatment; the target lesion has not received radiotherapy or has recurred in the radiotherapy field;
9. Appropriate hematopoiesis；
10. Appropriate liver function；
11. Appropriate renal function；
12. Normal coagulation;
13. Females of childbearing potential willing to use contraception during the trial: negative serum or urine pregnancy test within 7 days prior to dosing.

Exclusion Criteria:

1. Received radiation therapy within 28 days prior to enrollment. Radiotherapy for the relief of metastatic bone pain prior to enrollment is permitted, provided that no more than 30% of the total marrow-containing bone is irradiated, with the exception of patients with good bone feel prior to treatment;
2. The presence of evidence of central nervous system metastases;
3. Current or recent (within 30 days prior to enrollment) use of another investigational drug or participation in another clinical study
4. Other malignancy within 5 years (except adequately treated carcinoma in situ of the cervix or squamous carcinoma of the skin, or controlled basal cell carcinoma of the skin)
5. Uncontrolled hypertension (systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg despite optimal pharmacologic therapy)
6. Myocardial ischemia or myocardial infarction of class II or greater, poorly controlled arrhythmias (including qtc intervals ≥450 ms in men and ≥470 ms in women);
7. Grade III-IV cardiac insufficiency according to NYHA criteria, or cardiac ultrasound suggesting left ventricular ejection fraction (LVEF) \<50%;
8. Abnormal coagulation function (INR \> 1.5 or prothrombin time (PT) \> ULN + 4 seconds or APTT \> 1.5 ULN), with bleeding tendency or under thrombolytic or anticoagulant therapy;
9. Have had clinically significant bleeding symptoms or a definite bleeding tendency within the previous 3 months, such as gastrointestinal bleeding, bleeding gastric ulcer, fecal occult blood +++ or more at baseline, or have vasculitis
10. Have undergone major surgical procedures or have sustained a severe traumatic injury, fracture, or ulcer within the previous 4 weeks
11. Having factors that significantly affect the absorption of oral medication, such as inability to swallow, chronic diarrhea and intestinal obstruction, etc;
12. Urine routine suggestive of urinary protein ≥ ++, or confirmed 24-hour urine protein volume ≥ 1.0 g;
13. Plasmapheresis (including pleural fluid, ascites, and pericardial effusion) that is clinically symptomatic and requires surgical management;
14. Other conditions that, in the judgment of the investigator, may affect the conduct of the clinical study and the determination of the study results.