HLX49

HLX49 is a biparatopic antibody-drug conjugate (ADC) targeting the human epidermal growth factor receptor 2 (HER2), developed by Shanghai Henlius Biotech. It is engineered using the binding domains of HLX22, a HER2-specific monoclonal antibody licensed from AbClon. Unlike conventional HER2-targeted antibodies that bind to a single epitope, HLX49 is designed to bind to two distinct epitopes on the HER2 receptor. This biparatopic binding strategy is intended to enhance receptor clustering, internalization, and subsequent degradation, thereby improving the delivery of its cytotoxic payload into HER2-expressing cancer cells. HLX49 is being developed for the treatment of various HER2-positive or HER2-mutated solid tumors, including breast and gastric cancers, particularly in patients who may have developed resistance to existing HER2-targeted therapies.