On Dec. 20, 2019, the U.S. Food and Drug Administration (FDA) granted accelerated approval to Daiichi Sankyo’s Enhertu for the treatment of adults with unresectable or metastatic HER2-positive breast cancer who had received two or more prior anti-HER2-based regimens in the metastatic setting.

Enhertu is a human epidermal growth factor receptor 2 (HER2)-directed antibody and topoisomerase inhibitor conjugate, meaning that the drug targets the changes in HER2 that help the cancer grow, divide and spread, and is linked to a topoisomerise inhibitor, which is a chemical compound that is toxic to cancer cells.

HER2-positive breast cancer is a type of breast cancer that tests positive for a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells. Approximately one of every five breast cancers have a gene mutation in the cancer cells that makes an excess of the HER2 protein. HER2-positive breast cancers are an aggressive type of breast cancer.