X0306 4 2016-12-20 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 Stock option (right to buy) 18.56 2016-12-20 4 A 0 175000 0.00 A 2026-12-19 Common Stock 175000 175000 D Twenty-five percent (25%) of the shares subject to the option shall vest one year after December 20, 2016; thereafter one-forty-eighth (1/48th) of the shares subject to the option shall vest each month following the one year anniversary of December 20, 2016, so that all of the shares subject to the option shall be vested four (4) years after December 20, 2016. /s/ Frederick Driscoll, Attorney-in-Fact 2016-12-22