– Deruxtecan, a topoisomerase I inhibitor, is an exatecan derivative (DX-8951 derivative) with a cleavable pepetide linker and a maleimide group. The maleimide group in Deruxtecan can react with antibody to form antibody-drug conguates (ADC) such as Trastuzumab deruxtecan (DS-8201a), which is a HER2-targeting antibodydrug conjugate.