Efficacy and Safety of Metronomic Oral Vinorelbine Plus Anlotinib in HER2-negative Metastatic Breast Cancer Patients

Inclusion Criteria：

* Voluntarily sign an informed consent form;
* Females aged 18 years or older;
* ECOG physical performance status score of 0-2;
* Histologically confirmed HER2-negative metastatic breast cancer patients, and patients with locally recurrent disease who cannot undergo curative surgery or radiation therapy;
* HR-positive/HER2-negative advanced breast cancer patients who have primary endocrine resistance or disease progression after first-line endocrine ± targeted therapy;
* Triple-negative advanced breast cancer patients with disease progression after first-line chemotherapy ± immunotherapy;
* Blood routine examination meets the following conditions: ①absolute neutrophil count (ANC) ≥1.5×10\^9/L, ② platelets ≥100×10\^9/L, ③ hemoglobin ≥90 g/L, ④ white blood cell count ≥3.0×10\^9/L;
* The liver function meets the following criteria: ① serum total bilirubin ≤ 1.5 × ULN, and if there is liver metastasis, it should be ≤ 3 × ULN; ② AST or ALT ≤ 3 × ULN, and if there is liver metastasis, it should be ≤ 5 × ULN;
* The renal function meets the following criteria: serum creatinine ≤ 1.5 × ULN or creatinine clearance ≥ 50 mL/min (calculated according to the Cockroft-Gault formula);
* Female patients who meet the following criteria can participate in this study: ① Patients are not capable of reproduction; ② Patients have reproductive capacity, and have a negative result on the pregnancy test within 7 days before the first administration of the investigational drug, are not in the lactation period, and continuously adopt effective contraceptive measures before entering the study and during the entire study period and within 6 months after the last administration of the investigational drug.

Exclusion Criteria:

* Patients who have previously received treatment with vinorelbine and/or anlotinib;
* Patients with active or untreated brain metastasis;
* Patients who have had or currently have other malignancies within 5 years, except for cured cervical carcinoma in situ, non-melanoma skin cancer, and superficial bladder tumors \[Ta (non-invasive tumor), Tis (carcinoma in situ), and T1 (tumor invades basement membrane)\];
* Patients who have undergone major surgery (including thoracotomy biopsy) or suffered a significant trauma (such as bone fracture) within 4 weeks before randomization, have unhealed wounds or fractures at the time of screening, or are expected to undergo major surgery during the study period;
* Patients with a history of myocardial infarction within the past 6 months; history of congestive heart failure with New York Heart Association (NYHA) classification ≥ II, or severe arrhythmia (excluding atrial fibrillation and paroxysmal supraventricular tachycardia) that cannot be controlled by medication;
* Patients with known allergies to the drugs and their excipients involved in this trial;
* Patients with a known history of hypersensitivity reactions to any investigational drugs;
* Patients who are simultaneously participating in other trials;
* Patients who cannot evaluate the efficacy of the treatment plan with existing technology;
* Patients judged unsuitable for participation by other investigators.