X0508 4 2025-12-30 0 0001439222 AGIOS PHARMACEUTICALS, INC. AGIO 0001900772 Burns James William 88 SIDNEY STREET CAMBRIDGE MA 02139 0 1 0 0 Chief Legal Officer 1 Common stock 2025-12-30 4 M 0 6000 0 A 34650 D Common stock 2025-12-30 4 S 0 2932 27.09 D 31718 D Performance share units 2025-12-30 4 M 0 6000 0 D Common stock 6000 0 D Shares sold to cover the tax withholding obligation in respect of vesting of the reporting person's performance share units. This transaction was effected pursuant to durable automatic sale instructions consistent with the affirmative defense to liability under Section 10(b) of the Securities Exchange Act of 1934 under Rule 10b5-1(c) promulgated under such Act. Such instructions were included in the reporting person's performance share unit agreement dated March 1, 2023. Each performance share unit represents a contingent right to receive one share of the issuer's common stock. The PSUs were granted on March 1, 2023. The PSUs vest as to 50% of the underlying shares upon the achievement of a specified research milestone and as to the remaining 50% of the underlying shares upon the achievement of a specified regulatory milestone. The performance criteria for the specified regulatory milestone was determined to have been met on December 29, 2025, resulting in the vesting of the PSUs as to 50% of the underlying shares. Vested shares will be delivered to the reporting person within three business days after such shares become vested. /s/ William Cook, as Attorney in Fact for James Burns 2026-01-02