HER2-positive breast cancer – Available anti-HER2 therapies and new agents under investigation

Abstract

Introduction and objectives Breast cancer (BC) is the most common malignancy and the leading cause of cancer death among women. About 15–20% of all BCs are HER2-positive. Proper assessment of HER2 status is crucial to choose appropriate treatment. The review summarizes data on anti-HER2 drugs used to treat HER2-positive BC and provides basic information on new agents under investigation. Brief description of the state of knowledge. Specific HER2-targeting drugs are available or are being evaluated in clinical trials. Anti-HER2 agents include: monoclonal antibodies, tyrosine kinase inhibitors, antibody-drug conjugates, bispecific antibodies, PI3K/AKT/mTOR inhibitors and heat shock protein 90 inhibitors, HER2-targeting vaccines and CDK4/6 inhibitors. The advent of anti-HER2 therapies increased the time of progression free survival and overall survival in BC patients. Results Final analysis of the CLEOPATRA trial shows that the combination of trastuzumab, pertuzumab and taxane significantly improved outcomes in metastatic HER2-positive BC and it is currently preferred first-line treatment. The recommended second-line treatment is based on trastuzumab emtansine or on the combination of lapatinib and capecitabine. Some promising agents such as margetuximab or trastuzumab deruxtecan are still under investigation. Conclusions Anti-HER2 directed treatment undoubtedly improves outcomes among patients with HER2-positive BC. Access to drugs such as trastuzumab, pertuzumab, lapatinib and T-DM1 improves prognosis even in patients with advanced disease. Further studies and clinical trials on novel anti-HER2 therapies are required. Nevertheless, BC treatment is becoming more effective and, hopefully, one day it may be possible to cure patients even with metastases.

Keywords

• breast cancer
• targeted therapies
• her2-positive breast cancer
• her2-targeting treatment
• anti-her2 drugs