X0306 4 2020-07-16 0 0001419600 Flexion Therapeutics Inc FLXN 0001597407 Clayman Michael D. C/O FLEXION THERAPEUTICS, INC. 10 MALL ROAD, SUITE 301 BURLINGTON MA 01803 1 1 0 0 President and CEO Common Stock 2020-07-16 4 A 0 93750 0.00 A 160010 D Common Stock 346605 I By the Michael D.Clayman 2006 Revocable Trust Common Stock 24600 I By the Michael D. Clayman Irrevocable Trust Common Stock 388683 I By Versant Development Fund III, LLC Represents restricted stock unit award granted under the Issuer's 2013 Equity Incentive Plan. 1/3 of the shares subject to the restricted stock unit award vest on each of July 16, 2021, July 16, 2022 and July 16, 2023. Shares held by Versant Development Fund III, LLC. The Reporting Person is a manager and minority member of Versant Development Fund III, LLC. The Reporting Person disclaims any beneficial ownership of the shares held by Versant Development Fund III, LLC except to the extent of his pecuniary interest in these shares. /s/ Mark S. Levine, Attorney-in-Fact 2020-07-20