A Study of BL-B01D1 in Patients With Locally Advanced or Metastatic Gastrointestinal Tumor and Other Solid Tumor

Inclusion Criteria:

1. Participants must sign the informed consent form voluntarily and follow the planrequirements.

2. No gender limit.

3. Age: ≥18 years old and ≤75 years old (phase Ia); ≥18 years old (phase Ib).

4. Expected survival time ≥ 3 months.

5. Patients with locally advanced or metastatic triple-negative breast cancer or othersolid tumors who have been diagnosed histopathologically and/or cytologically asfailing standard therapy, or who are not eligible for standard therapy at thisstage, and who are inoperable.

6. Agree to provide archived tumor tissue samples or fresh tissue samples from theprimary tumor or metastatic tumor within 3 years (TROP2 protein expression in tumorpathological tissue to explore the correlation between TROP2 protein expression andBL-M02D1 validity index); If subjects are unable to provide tumor tissue samples,they will be admitted after evaluation by the investigator if other admissioncriteria are met.

7. Participants must have at least one assessable lesion as defined by RECIST V1.1.

8. Has an Eastern Cooperative Oncology Group performance status (ECOG PS) 0-1

9. The toxicity of previous antitumor therapy was restored to ≤1 as defined byNCI-CTCAE v5.0 (except for asymptomatic laboratory abnormalities considered by theinvestigators, such as elevated ALP, hyperuricemia, and elevated blood glucose;Toxicities with no safety risk, such as hair loss, grade 2 peripheral neurotoxicity,were excluded).

10. Has adequate organ function before registration, defined as: a) Bone marrowfunction: Absolute neutrophil count (ANC) ≥1.5×109/L, Platelet count ≥90×109/L,Hemoglobin ≥90 g/L; B) Hepatic function: Total bilirubin (TBIL≤1.5 ULN), AST and ALT ≤2.5 ULN for participants without liver metastasis, AST and ALT ≤5.0 ULN for livermetastases; c) Renal function: Creatinine (Cr) ≤1.5 ULN, or creatinine clearance (Ccr) ≥50 mL/min (according to the Cockcroft and Gault formula).

11. Coagulation function: International normalized ratio (INR)≤1.5, and activatedpartial thromboplastin time (APTT)≤1.5ULN.

12. Urinary protein ≤2+ or ≤1000mg/24h.

13. For premenopausal women with childbearing potential, a pregnancy test must be takenwithin 7 days prior to the start of treatment. Serum or urine pregnancy must benegative and must be non-lactating. Adequate barrier contraceptive measures shouldbe taken during the treatment and 6 months after the end of treatment for allparticipants (regardless of male or female).

Exclusion Criteria:

Patients screened for any of the following conditions will not be included in this study:

1. Chemotherapy, biological therapy, immunotherapy, radical radiotherapy, majorsurgery, targeted therapy (including small molecule inhibitor of tyrosine kinase),and other anti-tumor therapy within 4 weeks or 5 half-lives (whichever is shorter)prior to the first administration; mitomycin and nitrosoureas treatment within 6weeks prior to the first administration; oral fluorouracil-like drugs such as S-1,capecitabine, or palliative radiotherapy within 2weeks prior to the firstadministration.

2. Prior treatment with ADC drugs targeting TROP2 or ADC drugs using camptothecinderivatives (topoisomerase I inhibitors) as toxins.

3. Participants with history of severe heart disease, such as: symptomatic congestiveheart failure (CHF) ≥ grade 2 (CTCAE 5.0), New York Heart Association (NYHA) ≥ grade 2 heart failure, history of transmural myocardial infarction, unstable anginapectoris etc.

4. Participants with prolonged QT interval (male QTc> 450 msec or female QTc> 470msec), complete left bundle branch block, III grade atrioventricular block.

5. Active autoimmune diseases and inflammatory diseases, such as: systemic lupuserythematosus, psoriasis requiring systemic treatment, rheumatoid arthritis,inflammatory bowel disease and Hashimoto's thyroiditis, etc., except for type Idiabetes, hypothyroidism that can be controlled only by alternative treatment, andskin diseases that do not require systemic treatment (such as vitiligo, psoriasis).

6. The presence of a second primary tumor within 5 years prior to initialadministration, except for radical basal cell carcinoma of the skin, squamous cellcarcinoma of the skin, and/or radical resected carcinoma in situ.

7. Screening for unstable thrombotic events such as deep vein thrombosis, arterialthrombosis and pulmonary embolism requiring therapeutic intervention within thefirst 6 months; Infusion device-related thrombosis is excluded;

8. Unstable thrombotic events such as deep vein thrombosis, arterial thrombosis andpulmonary embolism requiring therapeutic intervention within 6 months prior toscreening; Thrombus formation associated with infusion set is excluded.

9. Symptoms of active central nervous system metastasis. However, patients with stablebrain parenchymal metastases can be enrolled. Stable was defined as: a. Theseizure-free state lasted for > 12 weeks with or without the use of antiepilepticdrugs; b. Glucocorticoid use is not required; c. Consecutive MRI scans (at least 8weeks between scans) showed stable imaging status.

10. Patients with a history of allergy to recombinant humanized antibody or mousechimeric antibody or to any excipients of BL-B01D1.

11. Previous recipients of organ transplantation or allogeneic hematopoietic stem celltransplantation (Allo-HSCT).

12. In previous adjuvant therapy with anthracyclines, the cumulative dose ofanthracyclines was > 360 mg/m2.

13. Positive human immunodeficiency virus antibody (HIVAb), active tuberculosis, activehepatitis B virus infection (HBV-DNA copy number > 103IU/ml) or active hepatitis Cvirus infection (HCV antibody positive and HCV-RNA > lower limit of detection).

14. Active infections requiring systemic treatment, such as severe pneumonia,bacteremia, septicemia, etc.

15. Participated in another clinical trial (calculated from the time of the last dose)within 4 weeks prior to the first dose.

16. The other conditions of participation in this clinical trial were not consideredappropriate by the investigators.