1. Having received systemic antitumor therapy within 4 weeks before first dose, including: Chemotherapy, macromolecular targeted therapy, antiangiogenic therapy, biotherapy, immunotherapy, radiotherapy (except palliative radiotherapy for bone metastasis pain relief), except:
1. Oral fluorouracil agents and small molecule targeted drugs within 2 weeks before first dose or within 5 half-lives (whichever is longer);
2. Traditional Chinese medicines with antitumor indications within 2 weeks before first dose.
2. Used or required to use strong CYP3A4 inhibitors/inducers within 2 weeks before first dose or during the study;
3. Previous treatment with antibody-drug conjugates (ADCs) containing topoisomerase I inhibitors as payload;
4. Having received systemic corticosteroid therapy (>10 mg prednisone equivalent daily for >7 days) or other immunosuppressants within 2 weeks before treatment initiation (inhaled/topical steroids or adrenal replacement therapy >10 mg prednisone equivalent permitted without active autoimmune disease);
5. Having received transfusion, EPO, TPO, IL-11, G-CSF or GM-CSF therapy within 2 weeks before first dose;
6. Having used or required to use QT-prolonging/shortening drugs within 7 days before first dose or during C-QTc study period, or have risk factors for QT prolongation/arrhythmia (e.g., heart failure, hypokalemia, congenital long QT syndrome, family history of long QT syndrome, or unexplained sudden death in first-degree relatives <40 years);
7. Severe cardiovascular/cerebrovascular disease history；
8. History of other primary malignancies (except cured localized tumors like basal cell carcinoma, squamous cell carcinoma of skin, superficial bladder cancer, carcinoma in situ of prostate/cervix/breast, or subjects with other primary tumors showing no recurrence for ≥5 years);
9. Clinically confirmed active pneumonia at screening or history of interstitial lung disease;
10. Uncontrolled serous effusions requiring frequent drainage or medical intervention at screening (e.g., pleural/peritoneal/pericardial effusions needing additional intervention within 2 weeks after initial treatment, excluding cytological examination);
11. Brain metastases or spinal cord compression at screening (except those completing local therapy with ≥4-week steroid discontinuation and stable imaging/neurological symptoms for ≥4 weeks before treatment initiation);
12. Severe unhealed wounds/ulcers/fractures, or major surgery within 4 weeks before first dose, or planned elective surgery during study;
13. Clinically confirmed active HBV or HCV.Active HBV definition: HBcAb or HBsAg positive with HBV DNA above ULN; Active HCV definition: HCV antibody positive with HCV RNA above ULN;
14. Active tuberculosis confirmed clinically, or TP-Ab positive, or HIV-Ab positive, or history of immunodeficiency diseases/organ transplantation/allogeneic hematopoietic stem cell transplantation;
15. Significant bleeding tendency within 4 weeks before first dose, investigator-assessed high-risk of gastrointestinal hemorrhage/hemoptysis, or congenital bleeding disorders/coagulopathy;
16. Active infection requiring medication or unexplained fever ≥38.5°C during screening;
17. History of psychotropic substance abuse, alcoholism, or drug addiction;
18. Pregnancy or lactation at screening;
19. Persistent adverse reactions from prior antitumor therapy not recovered to CTCAE v5.0 ≤Grade 1 or baseline (except alopecia/nail changes/other investigator-deemed non-safety concerns);
20. Investigator-determined ineligibility for study participation.