Efficacy and Safety Study of Disitamab Vedotin + RC148 vs. Albumin-Paclitaxone ± Toripalimab in HR-/HER2-low Breast Cancer

This trial is comparing two treatment regimens for people with HER2-low, hormone receptor-negative breast cancer that has spread or cannot be surgically removed. It tests a combination of two targeted antibody-drug conjugates (disitamab vedotin + RC148) against a standard chemotherapy regimen. **You may be eligible if...** - You have unresectable locally advanced or metastatic breast cancer - Your tumor is confirmed HER2-low and hormone receptor-negative - You have not previously received anti-HER2 treatment or immunotherapy - Your cancer has measurable areas on imaging - Your organ function and blood counts meet required levels - Your general health is good (ECOG 0 or 1) **You may NOT be eligible if...** - You have previously received anti-HER2 therapy or immunotherapy in the metastatic setting - You have active, untreated brain metastases - You have significant heart disease or active lung disease - You have active hepatitis B, C, or HIV - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.