There have been remarkable advances in the field of anti-HER2 biologic agents. The benefits of trastuzumab, pertuzumab, lapatinib, and ado-trastuzumab emtansine (T-DM1) have all been well studied, but each drug also has its own set of complications and toxicities. Most concerning for trastuzumab is cardiotoxicity; understanding how to monitor for and treat cardiotoxicity is paramount. Diarrhea and rash are potentially troubling side effects seen with lapatinib. Pertuzumab has not been shown to have a high frequency of cardiotoxicity, but cytopenias, diarrhea, and rash can be seen with this medication. With T-DM1, rash and diarrhea are less-common side effects, but thrombocytopenia and transaminitis can be problematic. It is important to know what side effects to monitor for and how to properly manage them in order to best support patients through these biologic treatments. In this review, we discuss the main adverse-event profile of each biologic agent and provide concise management recommendations.
Targeted biologic agents may increase efficacy with less toxicity as compared with traditional cytotoxic chemotherapy. Currently there are four targeted agents that are US Food and Drug Administration (FDA)-approved for clinical use for human epidermal growth factor receptor 2 (HER2)-positive breast cancer: trastuzumab, pertuzumab, lapatinib, and ado-trastuzumab emtansine (T-DM1). However, these agents have potentially serious toxicities (Table 1
). Knowledge of common complications or adverse events (AEs) will enable oncologists to make more informed treatment decisions for each individual patient. The objectives of this review are to provide a current description of the safety profiles of anti- HER2-targeted agents used in breast cancer, and to outline practical recommendations for management of toxicities.
Table 1. Common or Severe Toxicities of Anti-HER2 Biologic Agents