A Study Comparing BL-B01D1 in Combination With Osimertinib Versus Osimertinib Alone in Patients With Locally Advanced, Unresectable EGFR-mutated Non-small Cell Lung Cancer(Stage III) Whose Disease Has Not Progressed Following Definitive Platinum-based Chemoradiation Therapy(PANKU-Lung08)

Prior treatment

• The trial participant has received other chemotherapy, radiotherapy, etc., for NSCLC apart from radical chemoradiotherapy;
• Major surgery within 4 weeks prior to the first dose;
• Any thrombotic events such as deep vein thrombosis, arterial thrombosis, or pulmonary embolism within 6 months prior to screening;
• Diagnosis of active malignancy within 5 years prior to study randomization;
• Concurrent lung disease resulting in clinically severe respiratory impairment;
• Severe infection within 4 weeks prior to study randomization;
• Severe non-healing wounds, ulcers, or fractures within 4 weeks prior to signing informed consent;
• Trial participants with clinically significant bleeding or a clear tendency for bleeding within 4 weeks prior to signing informed consent;
• History of allergy to recombinant humanized antibodies or chimeric human-mouse antibodies, or allergy to any excipient components of the investigational drug;
• Trial participants 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;
• Hypertension poorly controlled by two antihypertensive medications;
• Current radiation pneumonitis of Grade ≥2 as defined by CTCAE;
• Trial participants with a history of inflammatory bowel disease, extensive bowel resection, or immune-mediated enteritis;
• History of autologous or allogeneic stem cell transplantation;
• Positive for human immunodeficiency virus antibodies, active hepatitis B virus infection, or hepatitis C virus infection;
• History of severe neurological or psychiatric disorders, or a history of substance abuse, alcoholism, or drug addiction;
• Other conditions deemed by the investigator as unsuitable for participation in this clinical trial due to complications or other reasons.

Lab values

• Prior treatment with ADC drugs using topoisomerase I inhibitors as toxins, or antibodies/ADCs targeting EGFR and/or HER3;
• Prolonged QTc interval, complete left bundle branch block, second- or third-degree atrioventricular block, or frequent and uncontrolled arrhythmias;
• Trial participants with poorly controlled blood glucose levels;

Other

• SCLC, mixed SCLC and NSCLC, or other non-NSCLC pathological types;
• Large serous cavity effusions or symptomatic serous cavity effusions;
• Imaging findings suggesting 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 and ≤ 75 years, regardless of gender;
• Expected survival time ≥ 3 months;
• Unresectable Stage III non-small cell lung cancer;
• Detection of one of the EGFR-sensitive mutation types in tumor tissue;
• Agree to provide archived primary tumor tissue specimens or fresh tissue samples within 1 year;
• In platinum-based radical chemoradiotherapy, the platinum-containing chemotherapy regimen must include one of the specified drugs in addition to the platinum agent;
• In platinum-based radical chemoradiotherapy, patients must have received a total radiation dose of 60 Gy ± 10% before randomization;
• Toxicities from prior chemoradiotherapy must have resolved to ≤ Grade 1 as defined by NCI-CTCAE v6.0;
• ECOG performance status score of 0 or 1;
• No severe cardiac dysfunction, with left ventricular ejection fraction ≥ 50%;
• Organ function levels must meet the requirements;
• Urine protein ≤ 1+ or \< 1000 mg/24h;
• For premenopausal women with childbearing potential, a serum pregnancy test must be performed within 7 days before starting treatment, and the test must rule out pregnancy; they must not be lactating; all enrolled trial participants must take adequate barrier contraceptive measures throughout the treatment period and for 7 months after treatment ends.