Stephen R. Biggar, M.D., Ph.D., has served as an ACADIA director since January 2013 and as Chair of the Board since June 2016. He is a Partner at Baker Bros. Advisors LP, a registered investment adviser focused on long-term investments in life-sciences companies, which he joined in 2000. He currently serves on the boards of Kiniksa Pharmaceuticals and TScan Therapeutics. He received an M.D. and a Ph.D. in immunology from Stanford University and a B.S. in genetics from the University of Rochester.