A Phase II Study of HLX22 in Combination With Trastuzumab Deruxtecan in HER2-low, Hormone Receptor Positive Locally Advanced or Metastatic Breast Cancer Patients

Inclusion Criteria

• •1. Male/female who are at least 18 years of age on the day of signing the informed consent.
• •2. With histologically confirmed diagnosis of HER2-low, Hormone Receptor Positive Locally Advanced or Metastatic Breast Cancer.
• •3. HER2-low defined as IHC 2+/ISH- or IHC 1+ (ISH- or untested) as assessed by a central laboratory on metastatic tumor and was never previously HER2-positive，and was documented HR+ disease in the metastatic setting
• •4. Had measurable disease according to the RECIST v1.1, the target lesion must not be a bone metastatic lesion only.
• •5. ECOG PS: 0-1.
• •6. Expected survival ≥ 6 months.
• •7. Had adequate organ function