A Study Comparing BL-B01D1 Combined With Tislelizumab Versus Platinum-containing Chemotherapy Combined With Tislelizumab as First-line Treatment in Patients With Extensive-stage Small Cell Lung Cancer(PANKU-Lung07)

Prior treatment

• Patients who have previously received systemic treatment;
• Previous treatment with ADC drugs where the small molecule toxin is a topoisomerase I inhibitor;
• Use of immunomodulatory drugs within 14 days prior to the first dose of the study drug;
• Receiving long-term systemic corticosteroid therapy at a dose \>10 mg/day of prednisone or equivalent prior to the first dose;
• Unstable thrombotic events requiring therapeutic intervention within 6 months prior to screening;
• Diagnosis of active malignancy within 3 years prior to study randomization;
• Concurrent pulmonary disease resulting in clinically severe impairment of respiratory function;
• Severe infection within 4 weeks prior to study randomization;
• Severe, non-healing wound, ulcer, or bone fracture within 4 weeks prior to signing informed consent;
• Subjects with clinically significant bleeding or obvious bleeding tendency within 4 weeks prior to signing informed consent;
• Receipt of other unapproved clinical study drugs or treatments within 4 weeks prior to study randomization;
• Subjects planning to receive or having received live vaccines within 28 days prior to study randomization;

Other illness

• History of severe heart disease or cerebrovascular disease;
• Active autoimmune diseases and inflammatory diseases;
• Hypertension inadequately controlled with two antihypertensive medications;
• Poorly controlled diabetes mellitus;
• History of interstitial lung disease (ILD)/pneumonitis requiring steroid therapy, etc.;
• Patients with inflammatory bowel disease, history of extensive bowel resection, history of immune-related enteritis, intestinal obstruction, or chronic diarrhea;
• History of allergy to recombinant humanized antibodies or any excipient component of BL-B01D1;
• History of autologous or allogeneic stem cell transplantation;
• Positive for human immunodeficiency virus antibody, active hepatitis B virus infection, or hepatitis C virus infection;
• History of severe neurological or psychiatric disorders;
• Other conditions deemed by the investigator to make the subject unsuitable for participation in this clinical trial due to complications or other circumstances.

Lab values

• Prolonged QT interval, complete left bundle branch block, etc.;

Other

• Pathology indicates small cell carcinoma containing non-small cell carcinoma components;
• Patients with active central nervous system (CNS) metastases;
• Presence of large serous cavity effusions, or serous cavity effusions with symptoms, etc.;
• Imaging findings indicating tumor invasion or encasement of major blood vessels in the abdomen, chest, neck, or pharynx;

• Voluntarily sign the informed consent form and comply with the protocol requirements;
• Age ≥ 18 years;
• Expected survival time ≥ 3 months;
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1;
• Patients with histopathologically and/or cytologically confirmed extensive-stage small cell lung cancer;
• Agree to provide archived tumor tissue specimens from the primary or metastatic lesions within 3 years, or fresh tissue samples;
• Must have at least one measurable lesion as defined by RECIST v1.1;
• Toxicity from prior anti-tumor therapy must have recovered to ≤ Grade 1 as defined by NCI-CTCAE v5.0;
• No severe cardiac dysfunction, with left ventricular ejection fraction ≥ 50%;
• Organ function levels must meet the requirements;
• Urinary protein ≤ 2+ or \< 1000 mg/24h;
• For premenopausal women of childbearing potential, a pregnancy test must be performed within 7 days before starting treatment, and the serum pregnancy test must be negative; patients must not be breastfeeding. All enrolled patients (regardless of male or female) must use adequate barrier contraception throughout the entire treatment period and for 6 months after the end of treatment.