Yat-Sun Or is the Senior Vice President and Chief Scientific Officer at Enanta Pharmaceuticals, where he has directed drug discovery since 1999. He is a prolific inventor with over 260 filed U. S. patent applications and holds a Ph. D. in Organic Chemistry from the University of Chicago.
He is the co-inventor of Enantas commercially successful protease inhibitors, glecaprevir (MAVYRET®) and paritaprevir (VIEKIRA PAK®), for the treatment of chronic hepatitis C virus.