First clinical experience with trastuzumab deruxtecan in Switzerland

Breast cancer is the most common type of cancer worldwide (1). In Switzerland, more than 6000 women are diagnosed every year (2). In 15–20 % of all breast cancers, the human epidermal growth factor receptor 2 (HER2) gene is amplified, overexpressed, or both (3). In these patients, the risk of metastases and recurrence is higher and outcomes have historically been poor, until HER2-targeted therapies including monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs) have revolutionized patients’ treatment and improved survival rates (3).