A Study Comparing BL-B01D1 With Chemotherapy of Physician's Choice in Patients With Unresectable Locally Advanced or Metastatic Triple-Negative Breast Cancer(PANKU-Breast02)

Inclusion criteria

• Voluntarily sign the informed consent and follow the requirements of the protocol;
• No gender limit;
• Age ≥18 years old and ≤75 years old;
• Expected survival time ≥3 months;
• Patients with unresectable, locally advanced or metastatic triple-negative breast cancer;
• Consent to provide archival tumor tissue samples or fresh tissue samples of primary or metastatic lesions within 3 years;
• The subjects had received 1-2 lines of chemotherapy regimens in the locally advanced or metastatic stage, and had been treated with taxanes previously;
• Acceptability of chemotherapy with eribulin, capecitabine, gemcitabine, or vinorelbine, as assessed by the investigator;
• Patients with baseline brain metastases should have received treatment for all brain metastases and be stable;
• Must have at least one measurable lesion that meets the RECIST v1.1 definition;
• ECOG score 0 or 1;
• Toxicity of previous antineoplastic therapy has returned to ≤ grade 1 defined by NCI-CTCAE v5.0;
• No severe cardiac dysfunction, left ventricular ejection fraction ≥50%;
• No blood transfusion, no use of cell growth factors and/or platelet raising drugs within 14 days before the first use of the study drug, and the organ function level must meet the requirements;
• Coagulation function: international normalized ratio ≤1.5, and activated partial thromboplastin time ≤1.5×ULN;
• Urine protein ≤2+ or < 1000mg/24h;
• For premenopausal women with childbearing potential, a pregnancy test must be performed within 7 days before the initiation of treatment, serum pregnancy must be negative, and must be non-lactating; All enrolled patients (male or female) were advised to use adequate barrier contraception throughout the treatment cycle and for 6 months after the end of treatment.

Exclusion criteria

• Prior receipt of an ADC with a TOPI inhibitor as a toxin;
• Prior receipt of an ADC or antibody drug targeting EGFR and/or HER3;
• Chemotherapy, biological therapy, immunotherapy, etc. within 4 weeks or 5 half-lives before the first dose, small molecule targeted therapy within 5 days, palliative radiotherapy and anti-tumor therapy within 2 weeks;
• Anthracycline equivalent cumulative dose of adriamycin > 360 mg/m2;
• History of severe cardiovascular or cerebrovascular disease;
• Unstable thrombotic events requiring therapeutic intervention within 6 months before screening;
• QT prolongation, complete left bundle branch block, III degree atrioventricular block, frequent and uncontrollable arrhythmia;
• Active malignancy diagnosed within 5 years before randomization;
• Hypertension poorly controlled by two antihypertensive drugs;
• Patients with poor blood glucose control before the first dose;
• A history of interstitial lung disease requiring steroid therapy, or current radiation pneumonitis, or a suspicion of such disease;
• Complicated with pulmonary diseases leading to clinically severe respiratory impairment;
• Patients with carcinomatous meningitis (meningeal metastasis) or brain stem metastasis or spinal cord compression;
• Have a history of allergy to recombinant humanized antibodies or any of the ingredients of BL-B01D1;
• A history of autologous or allogeneic stem cell transplantation;
• Human immunodeficiency virus antibody positive, active hepatitis B virus infection, or hepatitis C virus infection;
• Severe infection within 4 weeks before randomization; Evidence of pulmonary infection or active pulmonary inflammation within 2 weeks before randomization;
• Patients with massive or symptomatic effusions or poorly controlled effusions;
• Imaging examination showed that the tumor had invaded or enveloped the large blood vessels in the abdomen, chest, neck, and pharynx;
• Were receiving long-term systemic corticosteroids or equivalent active anti-inflammatory drugs or any form of immunosuppressive therapy before randomization;
• Received other unmarketed investigational drug or treatment within 4 weeks before the first dose;
• Patients with superior vena cava syndrome should not be rehydrated;
• A history of severe neurological or mental illness;
• Severe unhealed wound, ulcer, or fracture within 4 weeks before signing the informed consent;
• Subjects with clinically significant bleeding or obvious bleeding tendency within 4 weeks before signing the informed consent;
• History of intestinal obstruction, inflammatory bowel disease, or extensive bowel resection or presence of Crohn's disease, ulcerative colitis, or chronic diarrhea;
• Patients scheduled for vaccination or receiving live vaccine within 28 days before the first dose;
• Other circumstances that were assessed by the investigator as inappropriate for participation in the trial.