Inclusion Criteria:
1. Voluntarily sign the informed consent form and comply with the protocol requirements;
2. No gender restriction;
3. Age: ≥18 years and ≤75 years;
4. Expected survival time ≥3 months;
5. Locally advanced or metastatic gastrointestinal tumors and other solid tumors;
6. Agree to provide archival tumor tissue specimens from the primary or metastatic site within 3 years, or fresh tissue samples;
7. Must have at least one measurable lesion as defined by RECIST v1.1;
8. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with no deterioration within 2 weeks prior to the first dose;
9. Toxicities from prior anti-tumor therapy have recovered to ≤ Grade 1 as defined by NCI-CTCAE v6.0;
10. No severe cardiac dysfunction, with left ventricular ejection fraction ≥50%;
11. Organ function levels must meet the requirements;
12. Coagulation function: international normalized ratio ≤1.5, and activated partial thromboplastin time ≤1.5 × upper limit of normal;
13. Urine protein ≤1+ or ≤1000 mg/24 h;
14. For premenopausal women of childbearing potential, a pregnancy test must be performed within 7 days before starting treatment, with serum pregnancy results being negative, and they must be non-lactating; all enrolled patients (regardless of male or female) must adopt adequate barrier contraceptive measures throughout the entire treatment period and for 6 months after the completion of treatment;
15. The trial participant is capable and willing to comply with the visit schedule, treatment plan, laboratory tests, and other study-related procedures specified in the protocol.
Exclusion Criteria:
1. Use of chemotherapy, biological therapy, immunotherapy, etc., within 4 weeks or 5 half-lives prior to the first dose;
2. History of severe cardiac or cerebrovascular disease;
3. Prolonged QTc interval, complete left bundle branch block, third-degree atrioventricular block, or frequent and uncontrolled arrhythmias;
4. Active autoimmune diseases and inflammatory diseases;
5. Diagnosis of another malignant tumor within 5 years prior to the first dose;
6. Unstable thrombotic events requiring therapeutic intervention within 6 months prior to the first dose;
7. Hypertension inadequately controlled by antihypertensive medication;
8. Poorly controlled blood glucose;
9. History of interstitial lung disease requiring hormone therapy, or current ILD, or radiation pneumonitis of Grade ≥2;
10. Severe impairment of respiratory function;
11. Active central nervous system metastases;
12. Previous or concurrent central nervous system disorders;
13. History of allergy to recombinant humanized antibodies or human-mouse chimeric antibodies, or allergy to any excipient component of BL-M08D1;
14. Previous organ transplantation or allogeneic hematopoietic stem cell transplantation;
15. Positive for human immunodeficiency virus antibody, active tuberculosis, active hepatitis B virus infection, or active hepatitis C virus infection;
16. Active infection requiring systemic treatment within 4 weeks prior to the first study drug administration;
17. Pleural, abdominal, or pericardial effusion requiring drainage and/or accompanied by symptoms within 4 weeks prior to the first study drug administration;
18. Imaging findings indicating tumor invasion or encasement of abdominal, thoracic, cervical, or other regions;
19. Use of another investigational drug within 4 weeks or 5 half-lives prior to the first dose;
20. Pregnant or breastfeeding women;
21. Other conditions deemed by the investigator to make the patient unsuitable for participation in this clinical trial.
