X0306 4 2019-11-22 0 0001755237 Cyclerion Therapeutics, Inc. CYCN 0001723846 Huyett William C/O CYCLERION THERAPEUTICS, INC. 301 BINNEY STREET CAMBRIDGE MA 02142 0 1 0 0 Chief Financial Officer Employee Stock Option (Right to Buy) 2.01 2019-11-22 4 A 0 75000 0.00 A 2029-11-22 Common Stock 75000 75000 D The stock option grant will vest and become exercisable upon the attainment of both performance-based and service-based hurdles, as follows: (i) 20% of the shares subject to the option, if the average closing price of the common stock reported by Nasdaq for any thirty (30) consecutive trading days equals or exceeds $10; plus an additional (ii) 40% of the shares, if the average closing price equals or exceeds $20; plus an additional (iii) 40% of the shares, if the average closing price equals or exceeds $30; in each case, subject to the continuous employment or service through the later of the date that the performance hurdles set forth above are attained (but no later than December 31, 2024) and December 31, 2021. To the extent unvested as of December 31, 2024, all unvested shares underlying such performance-based option will be cancelled. /s/ David Slatcher, Attorney-in-Fact 2019-11-26