X0306 4 2019-07-10 0 0001755237 Cyclerion Therapeutics, Inc. CYCN 0001478485 Hecht Peter M C/O CYCLERION THERAPEUTICS, INC. 301 BINNEY STREET CAMBRIDGE MA 02142 1 1 0 0 Chief Executive Officer Common Stock 2019-07-10 4 M 0 2000 6.04 A 225192 D Common Stock 485 I The 2000 Trust for Alexis Mae Hecht Common Stock 485 I The 2000 Trust for Malcolm Paul Hecht Common Stock 485 I The 2000 Trust for Zoe Niovi Hecht Employee Stock Option (Right to Buy) 6.04 2019-07-10 4 M 0 2000 0.00 D 2019-07-28 Common Stock 2000 0 D This transaction represents the acquisition of common stock as a result of the exercise and hold of derivative securities reported in Table II. These shares are held in the referenced trust for the benefit of the reporting person's child. The reporting person's spouse is the trustee of this trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or any other purpose. This option to purchase 20,167 shares vests in installments upon achievement of certain regulatory and commercial milestones. The option has vested as to 2,000 shares as of the date hereof. /s/ Larry Miller, Attorney-in-Fact 2019-07-12