SHR-A1811 Alone or in Combination With Adebrelimab as Neoadjuvant Treatment in HR Positive/HER2 Low Breast Cancer

This study tests a new combination of drugs — SHR-A1811 (an antibody-drug combination targeting HER2) with or without adebrelimab (an immunotherapy drug) — as pre-surgery (neoadjuvant) treatment for a specific subtype of breast cancer that is hormone receptor-positive but has low HER2 expression. **You may be eligible if...** - You are a woman aged 18 to 75 - You have been diagnosed with hormone receptor-positive (HR+), HER2-low invasive breast cancer, confirmed by biopsy - Your cancer is stage II or III and you have not received any prior treatment - Your overall health status is good (ECOG 0 or 1) - Your organ function is adequate **You may NOT be eligible if...** - You have received any prior anti-cancer treatment for this cancer - You have bilateral (both breasts), inflammatory, or hidden (occult) breast cancer - Your cancer is stage IV (metastatic) - You have had any other cancer in the past 5 years (except cured cervical cancer in situ or treated melanoma skin cancer) - You have a history of immunodeficiency, serious heart disease, interstitial lung disease, active hepatitis, or a bleeding/clotting disorder - You participated in another drug clinical trial within the past 4 weeks Talk to your doctor to see if this trial is right for you.