X0306 4 2021-01-20 0 0001253689 GLYCOMIMETICS INC GLYC 0001589712 King Rachel K. C/O GLYCOMIMETICS, INC. 9708 MEDICAL CENTER DRIVE ROCKVILLE MD 20850 1 1 0 0 President, CEO Common Stock 2021-01-20 4 A 0 96250 0.00 A 452314 D Common Stock 129401 I By trusts Common Stock 45741 I By spouse Employee Stock Option (right to buy) 3.81 2021-01-20 4 A 0 192500 0.00 A 2031-01-19 Common Stock 192500 192500 D The security represents restricted stock units granted to the reporting person. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer. 25% of these restricted stock units vest on each of January 20, 2022, 2023, 2024 and 2025, subject to the reporting person's continuous service as of each such vesting date. These shares are held by family trusts, for which Ms. King serves as trustee, as follows: 1,741 shares are held by The Connor A. King 1988 Trust, 1,741 shares are held by The Langley C. King 1990 Trust, 8,796 shares are held by the 1995 Connor A. King Trust, 8,796 shares are held by the 1995 Langley C. King Trust, 23,301 shares are held by The Connor King 2013 GRAT, 23,301 shares are held by The Langley C. King 2013 GRAT and 61,725 shares are held by The Rachel K. King 2016 GRAT. 25% of the shares underlying this option vest on January 20, 2022 and the balance of the shares vest in a series of 36 successive equal monthly installments thereafter, subject to the reporting person's continuous service as of each such vesting date. /s/ Brian Leaf, attorney-in-fact 2021-01-22