HER3-DXd has shown a manageable safety profile characterized by a treatment-related discontinuation rate due to adverse events (AEs) of approximately 10%, gastrointestinal and hematologic toxicities as the most common treatment-emergent adverse events (TEAEs) and evidence of relevant anti-tumor activity in clinical trials in EGFR-mutated NSCLC and breast cancer15,16. This evidence concerns the gene ERBB3 and neoplasm.