Skip to content


Theonie Anastassiadis

Senior Principal

Theonie Anastassiadis, Ph.D., joined Flagship Pioneering in 2018 after completing the firm’s Flagship Pioneering Fellowship. Theonie works as part of a venture-creation team to develop the science, intellectual property, and business strategy to found and grow Flagship’s next breakthrough startups. She is a co-Founder and member of the founding team of the tRNA platform company Alltrna where she also serves as Chief Innovation Officer.

Before joining Flagship, Theonie received her Ph.D. in Cell and Molecular Biology with a focus in Cancer Biology from the Perelman School of Medicine at the University of Pennsylvania. Her research on replication fork dynamics in the context of cancer development and therapeutics was supported through multiple fellowships, including a 4-year NIH F31 NRSA Predoctoral Fellowship. Theonie also completed a Wharton Business Foundations Specialization and holds a B.S. in biology with honors from Haverford College.

Theonie’s work has resulted in multiple patents and publications, including articles in Nature Biotechnology, Molecular Cell, and Journal of Biological Chemistry. She was honored in 2022 in Endpoints News' 20 under 40 list of the next generation of biotech leaders and in Boston Business Journal's 40 under 40 list for successful professionals giving back to their community. She is a Business Advisory Board member of the Harvard Institute for RNA Medicine and a member of the Bioscience & Investor Inclusion Group (BIIG) Diverse Talent Network Group.