On November 19, 2023, Ole Isacson, M.D., Ph.D., tendered his resignation as a director of Cyclerion Therapeutics, Inc. effective immediately. Dr. Isacson served as Chair of the Compensation Committee and a member of the Audit Committee prior to his resignation. Dr. Isacson did not advise the Company of any disagreement with the Company on any matter relating to its operations, policies or practices.

The Company expects to announce the appointment of a new outside director shortly to replace Dr. Isacson on the Company?s Board of Directors.