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

This is a Phase II Study of HLX22 in Combination with Trastuzumab Deruxtecan (T-DXd) in HER2-low, Hormone Receptor Positive Locally Advanced or Metastatic Breast Cancer Patients with Disease Progression or Intolerable Adverse Reaction on Standard of Care. Eligible subjects will be treated with the study drug until the loss of clinical benefit, death, intolerable toxicity, withdrawal of informed consent, or other reasons specified by the protocol (whichever occurs first).