⁃ Eligibility Criteria:

• Female patients aged 18 to 70 years.

• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

• Histologically confirmed HR-positive/HER2-negative breast cancer (defined as: (1) ER-positive: ≥10% tumor cells positive by immunohistochemistry (IHC).

⁃ (2) PR-positive: ≥10% tumor cells positive by IHC. (3) HR-positive: ER and/or PR positive. (4) HER2-negative: HER2 0-1+ by IHC or HER2 2+ with negative FISH (no amplification).

⁃ 4\. Confirmed SNF2/3/4 subtype based on H\&E staining combined with digital pathology molecular subtyping.

⁃ 5\. Clinical tumor stage: cT1c-T2, cN1-N2 or cT3-T4, cN0-N2. 6. Agreement to undergo breast cancer surgery if meeting the criteria for resection after neoadjuvant therapy.

⁃ 7\. Adequate organ function, meeting the following criteria: Hemoglobin (Hb) ≥90 g/L; Absolute neutrophil count (ANC) ≥1.5×10⁹/L; Platelet count (PLT) ≥75×10⁹/L; Total bilirubin (TBIL) ≤1.5×ULN (upper limit of normal); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤3×ULN; Serum creatinine (Cr) ≤1×ULN; Creatinine clearance rate (CrCl) \>50 mL/min (calculated by Cockcroft-Gault formula).

⁃ 8\. Baseline left ventricular ejection fraction (LVEF) ≥55% measured by echocardiography or MUGA scan.

⁃ 9\. Negative serum pregnancy test for women of childbearing potential. Contraception requirement: Women of childbearing potential must use medically approved contraception during treatment and for at least 3 months after the last dose of the study drug.

⁃ 10Voluntary participation with signed informed consent, good compliance, and willingness to follow up.