X0306 4 2016-12-20 0 0001419600 Flexion Therapeutics Inc FLXN 0001129890 DRISCOLL FREDERICK W C/O FLEXION THERAPEUTICS, INC. 10 MALL ROAD, SUITE 301 BURLINGTON MA 01803 0 1 0 0 Chief Financial Officer Stock option (right to buy) 18.56 2016-12-20 4 A 0 50000 0.00 A 2026-12-19 Common Stock 50000 50000 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 2016-12-22