Advances in HER2-targeted therapy: Novel agents and opportunities beyond breast and gastric cancer

The introduction of HER2-targeted therapy for breast and gastric patients with ERBB2 (HER2) amplification/overexpression has led to dramatic improvements in oncologic outcomes. In the past 20 years, five HER2-targeted therapies have been FDA approved, with four approved in the past 8 years. HER2-targeted therapy similarly was found to improve outcomes in HER2-positive gastric cancer. Over the past decade, with the introduction of next-generation sequencing into clinical practice, our understanding of HER2 biology has dramatically improved. We have recognized that HER2 amplification is not limited to breast and gastric cancer but is also found in a variety of tumor types such as colon cancer, bladd cancer, and biliary cancer. Furthermore, HER2-targeted the apy has signal of activity in several tumor types. In addition t HER2 amplification and overexpression, there is also increase recognition of activating HER2 mutations and their potenti therapeutic relevance. Furthermore, there is a rapidly growin number of new therapeutics targeting HER2 including smal molecule inhibitors, antibody–drug conjugates, and bispecifi antibodies. Taken together, an increasing number of patien are likely to benefit from approved and emerging HER targeted therapies.