Weekly Utidelone in HER2-negative Inoperable Locally Advanced or Metastatic Breast Cancer

Inclusion Criteria: * Signed Informed Consent Form; * Women aged ≥ 18 years; * Histologically or cytologically confirmed HER2-negative locally advanced or metastatic breast cancer: * The most recent pathology confirmed HER2 negative, defined as HER2 0/1 + by standard immunohistochemical staining (IHC) or HER2 2 + by IHC but negative by in situ hybridization (ISH); * Patients with locally advanced or locally recurrent disease should be unable to undergo radical surgical resection confirmed by the investigators; * Eastern Cooperative Oncology Group (ECOG) score \[0-2\] points; * At least one evaluable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST1.1): * If there is only bone metastasis, it is required that the bone metastasis lesion contains bone destruction component; * if there is only pleural effusion, it is required that the pleural effusion is malignant confirmed by pathology * No more than 2 prior lines of chemotherapy for advanced and/or metastatic disease; * Prior chemotherapy regimens must have included taxane; * Patients with hormone receptor positive disease received at least one line of endocrine therapy for metastatic disease (including CDK4/6 inhibitors, everolimus, chidamide and PI3K inhibitors, etc.); * Patients must have recovered to ≤ Grade 1 (CTCAE v5.0) from all toxicities related to prior anticancer therapy. with the following exceptions: 1). alopecia; 2). pigmentation; * Adequate hematological, hepatic and renal functi…