Expansion Therapeutics launches to target RNA

Abstract

Add Expansion Therapeutics to the growing list of biotech companies developing small molecules that target RNA—the messenger molecule between DNA and proteins. The start-up launched last week with $55.3 million in series A funding. Most small-molecule drugs bind to proteins and chemists have shunned targeting RNA for years, due to its floppy structure and the difficulty of designing drugs that selectively target one RNA sequence. But Matthew Disney, a chemist at Scripps Research Institute in Florida, has been pushing to develop RNA-binding drugs for more than a decade. RNA folds and loops back on itself, creating a three-dimensional structure that small molecules can bind to. “That’s something that’s still not appreciated,” Disney says. To realize the concept, he is launching Expansion Therapeutics along with Kevin M. Forrest, who will serve as the firm’s CEO. The start-up’s first focus will be treatments for expansion repeat disorders, a group of about 30