Plitidepsin (also known as dehydrodidemnin B) is a chemical compound extracted from the ascidian Aplidium albicans. It is currently undergoing clinical trial testing. It is a member of the class of compounds known as didemnins.plitidepsin exhibits antitumor, antiviral and immunosuppressive activities. It shows promise in shrinking tumors in pancreatic, stomach, bladder, and prostate cancers.