Abstract
Breast cancer is one of the most common malignant tumors among women, which seriously threatens women's health. Human epidermal growth factor receptor 2 (HER2)-positive breast cancer, characterized by poor prognosis, is an aggressive phenotype accounting for 15-20% of all kinds of breast cancers. Therefore, it has attracted great interest among researchers in discovering targeted therapy drugs countering HER2, and they have been considered as the pivotal therapeutic regimen for HER2-positive breast cancer patients. Nowadays, large progress has been achieved in HER2-targeted drugs, and this review categorizes them into four types according to the drug action mode, including monoclonal antibodies (mAbs), tyrosine kinase inhibitors (TKIs), antibody-drug conjugates (ADCs), and bispecific antibodies (bsAbs). The progress of HER2-targeted drugs reflects the discovery of drug targets, the screening of drug compounds, and the modification of antibodies, which offer diverse medical options and better therapeutic benefits for individual patients. In detail, we focus on the indication, administration, efficacy, strengths, and challenges of HER2-targeted drugs, concerning approved drugs and clinical trials. This review aims to provide significant references for the targeted therapeutic regimen and a more precise treatment strategy for HER2-positive breast cancer.