X0306 4 2018-03-01 0 0001439222 AGIOS PHARMACEUTICALS INC AGIO 0001578200 Schenkein David P C/O AGIOS PHARMACEUTICALS, INC. 88 SIDNEY STREET CAMBRIDGE MA 02139 1 1 0 0 Chief Executive Officer Common stock 2018-03-01 4 M 0 13000 0.3025 A 13000 D Common stock 2018-03-01 4 S 0 2915 80.38 D 10085 D Common stock 2018-03-01 4 S 0 10085 81.30 D 0 D Common stock 271772 I See footnote Common stock 79082 I See footnote Stock option (right to buy) 0.3025 2018-03-01 4 M 0 13000 0.00 D 2019-08-12 Common stock 13000 91567 D This exercise was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. The price reported is the weighted average of the shares sold. The shares were sold at varying prices in the range of $79.80 to $80.79. The reporting person undertakes, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. The price reported is the weighted average of the shares sold. The shares were sold at varying prices in the range of $80.80 to $81.77. The reporting person undertakes, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Shares held by David P. Schenkein 2004 Revocable Trust, of which the reporting person is trustee and beneficiary. Shares held by Amy P. Schenkein 2004 Revocable Trust, of which the reporting person's spouse is trustee and beneficiary. This option was granted on August 13, 2009. The option vested as to 50% of the underlying shares upon the achievement of a performance milestone, as determined by the issuer's Board of Directors on June 3, 2010, and as to the remaining 50% of the underlying shares in equal monthly installments through June 3, 2013. /s/ William Cook, as Attorney in Fact for David Schenkein 2018-03-05