A Study of BL-B01D1 + PD-1 in Patients With Locally Advanced or Metastatic Urothelial Carcinoma

Inclusion Criteria:

1. All subjects voluntarily participated in the study and signed informed consent;

2. Male or female aged ≥18 years and ≤75 years;

3. Expected survival time ≥3 months;

4. ECOG 0-1;

5. Unresectable locally advanced or metastatic urothelial carcinoma confirmed byhistopathology and/or cytology;

6. Participants should not have received previous systemic therapy for locally advancedor metastatic urothelial cancer;

7. A biopsy sample of archived tumor tissue or metastatic urothelial carcinoma must beavailable within 3 years for PD-L1 and other testing;

8. At least one measurable lesion meeting the RECIST v1.1 definition was required;

9. The level of organ function must meet the requirements on the premise that bloodtransfusion and the use of any cell growth factors and/or platelet-raising drugs arenot allowed within 14 days before the first dose;

10. Previous treatment-related toxicity returned to ≤ grade 1 defined by NCI-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. Prior ADC recipients with TOPI inhibitors as toxin;

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

3. Prior immunotherapy with grade ≥3 irAE or grade ≥2 immune-related myocarditis;

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 &gt before the first dose; Long-term systemic corticosteroid therapy withprednisone 10mg/d;

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. History of ILD, current ILD, or suspected ILD;

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

13. Screening for unstable thrombotic events requiring therapeutic intervention withinthe preceding 6 months; Infusion-related thrombosis was excluded;

14. Patients with active central nervous system metastases;

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

16. Patients with a history of allergy to recombinant humanized antibody or human-mousechimeric antibody or allergic to any excipients of the test drug;

17. Prior organ transplantation or allogeneic hematopoietic stem cell transplantation (Allo-HSCT);

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. Severe unhealed wound, ulcer, or fracture within 4 weeks before signing the informedconsent;

25. Subjects with clinically significant bleeding or obvious bleeding tendency within 4weeks before signing 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.