Antibody-drug conjugates of 7-ethyl-10-hydroxycamptothecin: Sacituzumab govitecan and labetuzumab govitecan.

Monoclonal antibody (mAb), cytotoxins, and linker technology are three essential elements for developing a successful antibody-drug conjugate (ADC). In the research and development of ADCs industry, selected cytotoxins, such as auristatins and maytansines, are commonly tubulin inhibitors which are widely put into clinical use. Thereafter, with the booming development of ADCs, a large number of pharmaceutical companies have expanded a wide range of selectable cytotoxin product lines as well. Recently, the cytotoxic substance of 7-ethyl-10-hydroxycamptothecin (SN-38) conjugated to the monoclonal antibody by linker technology is developed as the second-generation ADCs. Here, the SN-38 families together with sacituzumab govitecan and labetuzumab govitecan are reviewed, whose features of metabolic pathway and toxicity in vivo are well-known. In sum, these methodology and technology would be convenient and flexible to be applied for developing the novel class of cytotoxins in ADCs industry.