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

Prior treatment

• Chemotherapy, biological therapy, immunotherapy, radical radiotherapy, major surgery, 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 6 weeks prior to the first administration; oral fluorouracil-like drugs such as S-1, capecitabine, or palliative radiotherapy within 2weeks prior to the first administration.
• Prior treatment with ADC drugs targeting TROP2 or ADC drugs using camptothecin derivatives (topoisomerase I inhibitors) as toxins.
• The presence of a second primary tumor within 5 years prior to initial administration, except for radical basal cell carcinoma of the skin, squamous cell carcinoma of the skin, and/or radical resected carcinoma in situ.
• Unstable thrombotic events such as deep vein thrombosis, arterial thrombosis and pulmonary embolism requiring therapeutic intervention within 6 months prior to screening; Thrombus formation associated with infusion set is excluded.
• Previous recipients of organ transplantation or allogeneic hematopoietic stem cell transplantation (Allo-HSCT).
• In previous adjuvant therapy with anthracyclines, the cumulative dose of anthracyclines was \> 360 mg/m2.
• Participated in another clinical trial (calculated from the time of the last dose) within 4 weeks prior to the first dose.

Other illness

• Patients screened for any of the following conditions will not be included in this study:
• Participants with history of severe heart disease, such as: symptomatic congestive heart failure (CHF) ≥ grade 2 (CTCAE 5.0), New York Heart Association (NYHA) ≥ grade 2 heart failure, history of transmural myocardial infarction, unstable angina pectoris etc.
• Active autoimmune diseases and inflammatory diseases, such as: systemic lupus erythematosus, psoriasis requiring systemic treatment, rheumatoid arthritis, inflammatory bowel disease and Hashimoto's thyroiditis, etc., except for type I diabetes, hypothyroidism that can be controlled only by alternative treatment, and skin diseases that do not require systemic treatment (such as vitiligo, psoriasis).
• Screening for unstable thrombotic events such as deep vein thrombosis, arterial thrombosis and pulmonary embolism requiring therapeutic intervention within the first 6 months; Infusion device-related thrombosis is excluded;
• Symptoms of active central nervous system metastasis. However, patients with stable brain parenchymal metastases can be enrolled. Stable was defined as: a. The seizure-free state lasted for \> 12 weeks with or without the use of antiepileptic drugs; b. Glucocorticoid use is not required; c. Consecutive MRI scans (at least 8 weeks between scans) showed stable imaging status.
• Patients with a history of allergy to recombinant humanized antibody or mouse chimeric antibody or to any excipients of BL-B01D1.
• Positive human immunodeficiency virus antibody (HIVAb), active tuberculosis, active hepatitis B virus infection (HBV-DNA copy number \> 103IU/ml) or active hepatitis C virus infection (HCV antibody positive and HCV-RNA \> lower limit of detection).
• Active infections requiring systemic treatment, such as severe pneumonia, bacteremia, septicemia, etc.
• The other conditions of participation in this clinical trial were not considered appropriate by the investigators.

Lab values

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

• Participants must sign the informed consent form voluntarily and follow the plan requirements.
• No gender limit.
• Age: ≥18 years old and ≤75 years old (phase Ia); ≥18 years old (phase Ib).
• Expected survival time ≥ 3 months.
• Patients with locally advanced or metastatic triple-negative breast cancer or other solid tumors who have been diagnosed histopathologically and/or cytologically as failing standard therapy, or who are not eligible for standard therapy at this stage, and who are inoperable.
• Agree to provide archived tumor tissue samples or fresh tissue samples from the primary tumor or metastatic tumor within 3 years (TROP2 protein expression in tumor pathological tissue to explore the correlation between TROP2 protein expression and BL-M02D1 validity index); If subjects are unable to provide tumor tissue samples, they will be admitted after evaluation by the investigator if other admission criteria are met.
• Participants must have at least one assessable lesion as defined by RECIST V1.1.
• Has an Eastern Cooperative Oncology Group performance status (ECOG PS) 0-1
• The toxicity of previous antitumor therapy was restored to ≤1 as defined by NCI-CTCAE v5.0 (except for asymptomatic laboratory abnormalities considered by the investigators, such as elevated ALP, hyperuricemia, and elevated blood glucose; Toxicities with no safety risk, such as hair loss, grade 2 peripheral neurotoxicity, were excluded).
• Has adequate organ function before registration, defined as: a) Bone marrow function: 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 liver metastases; c) Renal function: Creatinine (Cr) ≤1.5 ULN, or creatinine clearance (Ccr) ≥50 mL/min (according to the Cockcroft and Gault formula).
• Coagulation function: International normalized ratio (INR)≤1.5, and activated partial thromboplastin time (APTT)≤1.5ULN.
• Urinary protein ≤2+ or ≤1000mg/24h.
• For premenopausal women with childbearing potential, a pregnancy test must be taken within 7 days prior to the start of treatment. Serum or urine pregnancy must be negative and must be non-lactating. Adequate barrier contraceptive measures should be taken during the treatment and 6 months after the end of treatment for all participants (regardless of male or female).