This trial is a registered, phase III, randomized, open-label, multicenter study to evaluate the efficacy and safety of BL-B01D1 in patients with platinum-resistant recurrent epithelial ovarian cancer.

Inclusion Criteria:

1. Voluntarily sign the informed consent form and comply with the protocol requirements;
2. Age: ≥18 years old;
3. Expected survival time ≥3 months;
4. Histologically or cytologically confirmed epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer;
5. Previously treated with a platinum-based regimen and confirmed to have platinum-resistant recurrence;
6. Previously received 1-3 lines of systemic anti-tumor therapy, with radiographic evidence of disease progression during or after the last line of treatment or intolerance to the current treatment prior to randomization;
7. For subjects with documented folate receptor-alpha (FRα) positivity, progression must have occurred after treatment with mirvetuximab soravtansine;
8. Agree to provide archived tumor tissue specimens or fresh tissue samples from the primary or metastatic lesions within the past 3 years;
9. Must have at least one measurable lesion as defined by RECIST v1.1;
10. ECOG performance status score of 0 or 1;
11. Toxicity from prior anti-tumor therapy has recovered to ≤ Grade 1 as defined by NCI-CTCAE v5.0;
12. No severe cardiac dysfunction, with left ventricular ejection fraction ≥50%;
13. Organ function levels must meet the requirements;
14. Coagulation function: International Normalized Ratio (INR) ≤1.5, and activated partial thromboplastin time (APTT) ≤1.5×ULN;
15. For premenopausal women with childbearing potential, a serum pregnancy test must be performed within 7 days before starting treatment, and the result must be negative; they must not be breastfeeding. All enrolled patients should use adequate barrier contraception throughout the treatment period and for 6 months after treatment ends.

Exclusion Criteria:

1. Use of chemotherapy, targeted therapy, biologic therapy, etc., within 4 weeks or 5 half-lives prior to study randomization and palliative radiotherapy, etc., within 2 weeks;
2. Patients with locally advanced or metastatic platinum-resistant recurrent epithelial ovarian cancer who are eligible for radical locoregional therapy;
3. Front line received ADCs targeting topoisomerase I inhibitors or EGFR and/or HER3;
4. History of severe heart disease and cerebrovascular disease;
5. Unstable thrombotic events requiring therapeutic intervention within 6 months before screening;
6. Prolonged QT interval, complete left bundle branch block, III degree atrioventricular block, frequent and uncontrollable arrhythmia;
7. Diagnosed with active malignancy within 3 years before randomization;
8. Hypertension poorly controlled by two antihypertensive drugs;
9. Patients with poor glycemic control;
10. Patients with grade ≥1 radiation pneumonitis according to the RTOG/EORTC definition; Previous history of ILD;
11. Complicated with pulmonary diseases leading to clinically severe respiratory function impairment;
12. Patients with active central nervous system metastases;
13. Severe infection occurred within 4 weeks before randomization in study 13; Evidence of pulmonary infection or active pulmonary inflammation within 2 weeks before randomization;
14. Patients with massive or symptomatic effusions or poorly controlled effusions;
15. Imaging examination showed that the tumor had invaded or enveloped the large blood vessels in the abdomen, chest, neck, and pharynx;
16. Serious unhealed wound, ulcer or fracture within 4 weeks before signing the informed consent;
17. Subjects with clinically significant bleeding or obvious bleeding tendency within 4 weeks before signing the informed consent;
18. Patients with inflammatory bowel disease, extensive bowel resection, immune enteritis, intestinal obstruction or chronic diarrhea;
19. Patients with a history of allergy to recombinant humanized antibodies or to any of the excipients of BL-B01D1;
20. Had a history of autologous or allogeneic stem cell transplantation;
21. Human immunodeficiency virus antibody positive, active hepatitis B virus infection or hepatitis C virus infection;
22. A history of severe neurological or psychiatric illness;
23. Received other unmarketed investigational drugs or treatments within 4 weeks before randomization;
24. Subjects who were scheduled to be vaccinated or received live vaccine within 28 days before study randomization;
25. Other circumstances in which the investigator considered it inappropriate to participate in the trial because of complications or other circumstances.