Antibody-drug conjugates in HER2-positive breast cancer

Antibody-drug conjugates (ADCs) combine the high specificity of monoclonal antibodies with the high anti-tumor activity of small molecular cytotoxic payloads. The anti-tumor activity of ADCs is mainly achieved by the direct blocking of the receptor by monoclonal antibodies, direct action and bystander effect of cytotoxic drugs, and antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. ADCs have been used in adjuvant therapy and rescue treatment of human epidermal receptor 2 (HER2)-positive breast cancer, greatly improving the prognosis of breast cancer patients. Several ongoing clinical trials of ADC for breast cancer and other solid tumors proved the potential of ADCs will provide more promising treatment options for patients with malignant tumors. This review introduces the mechanism and latest clinical progress of ADC drugs approved for HER2-positive breast cancer to guide clinical practice and conduct research.