FDA018-ADC vs Investigator's Choice Chemotherapy to Treat Locally Advanced, Recurrent or Metastatic Triple-negative Breast Cancer

Inclusion Criteria:

1. Patients capable to give written informed consent;
2. Histologically or cytologically confirmed TNBC based on the most recent analyzed biopsy or other pathology specimen. Triple negative is defined as \<1% expression for estrogen receptor (ER) and progesterone receptor (PR) and negative for human epidermal growth factor receptor 2 (HER2) by in-situ hybridization;
3. Prior exposure to a taxane in localized or advanced/metastatic setting, and recurred during or after treatment;
4. Eligible for one of the chemotherapy options listed as ICC (eribulin, capecitabine, gemcitabine, or vinorelbine) as per investigator assessment;
5. Have measurable lesions defined in RECIST v.1.1, those with only skin or bone lesions cannot be included;
6. Expected survival≥3 months;
7. Eastern Cancer Cooperative Group (ECOG) performance status 0-1;
8. Adequate bone marrow, hepatic, and renal function;
9. All acute toxicity of previous anti-tumor treatment or surgery is relieved to baseline severity or NCI CTCAE version 5.0≤1;
10. Subjects could provide tumor tissues or tissue specimens;
11. Patients of child bearing potential must agree to take contraception during the study and for 6 months after the last day of treatment.

Exclusion Criteria:

1. Patients with other malignancies, except cured basal or squamous cell skin cancer or in situ cancer of cervix; and patients with other malignancies must have a tumor-free period of at least 5 years;
2. Have central nervous system metastasis with clinical symptoms;
3. Have history of clinical significant active chronic obstructive pulmonary disease, or other moderate-to-severe chronic respiratory illness present within 6 months prior to the first dose;
4. Suffering from active chronic inflammatory bowel disease (ulcerative colitis, Crohn disease), and history of intestinal obstruction, or Gl perforation;
5. Patients with Gilbert's disease or heterozygous for the UGT1A1\*28 allele;
6. Participants known to be human immunodeficiency (HIV) positive, hepatitis B positive, or hepatitis C positive;
7. Patients who have received prior TROP-2-targeted therapy;
8. Patients who have received prior topoisomerase I inhibitor contained therapy;
9. Received other anti-tumor treatments (including chemotherapy, radiotherapy, targeted therapy, immunotherapy, experimental treatment and so on) within 4 weeks prior to the first dose;
10. Patients who have received live vaccines within 4 weeks prior to the first dose;
11. Patients who had undergone major surgery or severe trauma within 4 weeks prior to the first dose;
12. Patients who had undergone systemic high-dose steroids within 2 weeks prior to the first dose;
13. Patients have history of psychotropic drug abuse, alcohol or drug abuse;
14. Women who are pregnant or lactating;
15. Other circumstances that is deemed not appropriate for the study by investigator.