A Study of BL-B01D1+PD-1 Monoclonal Antibody in Patients With Unresectable Locally Advanced or Recurrent Metastatic Triple-negative Breast Cancer

Inclusion Criteria:

1. Voluntarily sign the informed consent and follow the requirements of the protocol;

2. Age: ≥18 years old and ≤75 years old;

3. Expected survival time ≥3 months;

4. ECOG 0 or 1;

5. Subjects with histologically and/or cytologically confirmed, inoperable locallyadvanced or recurrent or metastatic triple-negative breast cancer;

6. Patients should not have received previous systemic therapy for unresectable,locally advanced, recurrent, or metastatic triple-negative breast cancer;

7. A archived tumor tissue specimen or fresh tissue specimen of the primary ormetastatic lesion within 2 years must be provided;

8. Must have at least one place in accordance with RECIST v1.1 define measurablelesions;

9. No blood transfusion, no use of cell growth factors and/or platelet raising drugswithin 14 days before screening, and the organ function level must meet therequirements;

10. Toxicity of previous antineoplastic therapy has returned to ≤ grade 1 defined byNCI-CTCAE v5.0;

11. For premenopausal women with childbearing potential, a pregnancy test must beperformed within 7 days before the initiation of treatment, the serum or urinepregnancy test must be negative, and the patient must not be lactating; All enrolledpatients should take adequate barrier contraception during the entire treatmentcycle and for 6 months after the end of treatment.

Exclusion Criteria:

1. ADC drugs that have received topoisomerase I inhibitors as small molecule toxins;

2. Palliative radiotherapy within 2 weeks before the first dose;

3. Patients with checkpoint inhibitors prior to neoadjuvant/adjuvant chemotherapy;

4. Use of an immunomodulatory drug within 14 days before the first dose of study drug;

5. The history of severe cardiovascular and cerebrovascular diseases in the past sixmonths was screened;

6. QT prolongation, complete left bundle branch block, III degree atrioventricularblock, frequent and uncontrollable arrhythmia;

7. Active autoimmune and inflammatory diseases;

8. Receiving long-term systemic corticosteroid therapy, etc., before the first dose;

9. Other malignant tumors that progressed or required treatment within 5 years beforethe first dose;

10. Presence of: a) poorly controlled diabetes mellitus before starting study treatment;b) severe complications associated with diabetes mellitus; c) a glycated hemoglobinlevel of 8% or more; d) hypertension poorly controlled by two antihypertensivedrugs; e) history of hypertensive crisis or hypertensive encephalopathy;

11. Present grade ≥2 radiation pneumonitis according to the RTOG/EORTC definition;Patients with current ILD;

12. Complicated with pulmonary diseases leading to clinically severe respiratoryimpairment;

13. 6 months prior to screening needs treatment intervention unstable thrombotic events;

14. Patients with active central nervous system metastases;

15. Patients with massive or symptomatic effusions or poorly controlled effusions;

16. Allergic history to recombinant humanized antibody or human-mouse chimeric antibodyor allergic to any excipients of the test drug;

17. Prior organ transplantation or allogeneic hematopoietic stem cell transplantation;

18. HIV antibody positive, active tuberculosis, active hepatitis B virus infection, oractive hepatitis C virus infection;

19. Serious infection within 4 weeks before the first dose of study drug; Signs ofpulmonary infection or active pulmonary inflammation within 4 weeks;

20. Participated in another clinical trial within 4 weeks before the first dose;

21. Patients with superior vena cava syndrome should not be rehydrated;

22. Have a history of psychotropic substance abuse with an inability to quit or ahistory of severe neurological or psychiatric illness;

23. Imaging examination showed that the tumor had invaded or wrapped the large thoracicvessels;

24. Serious unhealed wound, ulcer, or fracture within 4 weeks before signing theinformed consent;

25. Clinically significant bleeding or obvious bleeding tendency within 4 weeks beforesigning the informed consent;

26. Subjects who are scheduled to receive live vaccine or receive live vaccine within 28days before the first dose;

27. Other circumstances considered by the investigator to be inappropriate forparticipation in the trial.