Multicenter, Phase II Clinical Study of Sacituzumab Tirumotecan (Sac-TMT) in Combination With KL-A167 for Neoadjuvant Treatment of Triple-Negative Breast Cancer
This study is a multicenter phase II trial planning to enroll 40 patients with primary triple-negative breast cancer (tumor size ≥2 cm, clinical lymph node stage cN0-3, M0). Participants will receive the combination therapy of Sac-TMT and KL-A167 during the neoadjuvant treatment phase. The study aims to evaluate the efficacy and safety of Sac-TMT combined with KL-A167 as neoadjuvant treatment for triple-negative breast cancer.
• Age: 18-65 years old.
• Diagnosis: Histologically and/or cytologically confirmed primary triple-negative breast cancer (TNBC) (excluding inflammatory breast cancer), meeting the criteria of tumor size ≥2 cm, clinical lymph node stage cN0 to cN3, and M0 (no distant metastasis). TNBC Definition: Immunohistochemistry (IHC) showing ER and PR \<10%; HER2-negative: IHC 0 or 1+, or IHC 2+ with negative in situ hybridization (ISH).
• Tissue Sample: Availability of tumor tissue sample for biomarker testing.
• Measurable Disease: At least one measurable lesion according to RECIST v1.1 criteria. Lesions previously irradiated cannot be selected as target lesions. Subjects with only skin lesions or bone lesions are excluded.
• Performance Status: Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1 within 7 days prior to treatment initiation.
• Adequate Organ and Bone Marrow Function: Hematology: Absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L; Platelet count (PLT) ≥ 80 × 10⁹/L; Hemoglobin ≥ 10 g/dL. Liver Function: Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) ≤ 2.5 × upper limit of normal (ULN); Total bilirubin (TBIL) ≤ 1.5 × ULN. Renal Function: Creatinine clearance (Ccr) ≥ 60 mL/min (calculated using the Cockcroft-Gault formula). Coagulation: International normalized ratio (INR), activated partial thromboplastin time (APTT), and prothrombin time (PT) ≤ 1.5 × ULN. Cardiac Function: Left ventricular ejection fraction (LVEF) ≥ 55% as measured by echocardiography (ECHO) or multigated acquisition (MUGA) scan.
• Prior Treatment: No prior anti-tumor therapy for the current breast cancer.
• Contraception: Female subjects must have a negative serum pregnancy test. Female subjects of childbearing potential and male subjects with partners of childbearing potential must agree to use highly effective medically approved contraceptive methods from the time of signing the informed consent form until 6 months after the last dose of study drug.
• Informed Consent: Patients must voluntarily enroll in the study, provide written informed consent, and be able to comply with the protocol-specified visits and procedures.