Profile of Margetuximab: Evidence to Date in the Targeted Treatment of Metastatic HER2-positive Breast Cancer

Human epidermal growth factor receptor 2 (HER2) positive breast cancer accounts for about 20% of all breast cancers and this subtype has been historically associated with worse prognosis. Margetuximab is a chimeric and Fc-engineered monoclonal antibody directed to HER2 that can enhance the activation of the innate and adaptive immune responses while maintaining trastuzumab's antiproliferative effects. Margetuximab in combination with chemotherapy was approved by the US FDA in December 2020 for patients with metastatic HER2+ breast cancer who have received two or more HER2-targeted regimens. This approval was based on the results of the SOPHIA trial that showed a modest improvement in progression-free survival with margetuximab and chemotherapy compared to trastuzumab and chemotherapy. Ongoing studies are assessing the role of margetuximab in other settings and diseases such as early stage breast cancer and gastrointestinal malignancies. Here we review the rationale for the development of margetuximab, previous and ongoing clinical trials and current role in clinical practice.