This HCP guide is a condition of the Marketing Authorisation for Enhertu. It serves to minimise the important potential risk of medication error in addition to the SmPC. HCPs should read it before prescribing and administering Enhertu (trastuzumab deruxtecan). Risk of confusion between Enhertu (trastuzumab deruxtecan) and other trastuzumab-containing products including Kadcyla (trastuzumab emtansine).