United States securities and exchange commission logo

                             November 28, 2023

       Peter M. Hecht
       Chief Executive Officer
       Cyclerion Therapeutics, Inc.
       245 First Street, 18 Floor
       Cambridge , Massachusetts

                                                        Re: Cyclerion
Therapeutics, Inc.
                                                            Form 10-K for the
Fiscal Year Ended December 31, 2022
                                                            Filed March 22,
                                                            Form 10-Q for the
Quarterly Period Ended September 30, 2023
                                                            Filed November 13,
                                                            File No. 001-38787

       Dear Peter M. Hecht:

              We have limited our review of your filing to the financial
statements and related
       disclosures and have the following comments.

              Please respond to this letter within ten business days by
providing the requested
       information or advise us as soon as possible when you will respond. If
you do not believe a
       comment applies to your facts and circumstances, please tell us why in
your response.

                                                        After reviewing your
response to this letter, we may have additional comments.

       Form 10-Q for the Quarterly Period Ended September 30, 2023

       Notes to the Condensed Consolidated Financial Statements
       4. Discontinued Operations, page 14

   1.                                                   You disclose that on
May 11, 2023 you sold all of the assets comprising your zagociguat
                                                        and CY3018 programs
(Program Assets) to Tisento Therapeutics Inc. and have presented
                                                        the operations of the
Program Assets as discontinued operations for all periods presented.
                                                        Please explain to us
how you determined that the disposal of these programs results in a
                                                        strategic shift in your
operations given that you continue to hold other soluble guanylate
                                                        cyclase ("sGC")
stimulators in your product candidate portfolio.
 Peter M. Hecht
FirstName LastNamePeter
Cyclerion Therapeutics, Inc.M. Hecht
Comapany 28,
November   NameCyclerion
              2023          Therapeutics, Inc.
Page  2   28, 2023 Page 2
FirstName LastName
5. Other Investment, page 16

2.       You disclose that you acquired a 10% equity interest in Tisento
Therapeutics Holdings
         Inc.(Tisento Parent) with a fair value of $5.3 million and that your
investment does not
         provide you with significant influence over Tisento Parent. Please
address the following:
             Provide your analysis under ASC 810-10 in determining whether
Tisento Parent is a
              variable interest entity (VIE), including whether the entity has
sufficient equity at risk
              to finance its activities without additional subordinated
financial support.
             To the extent that Tisento Parent is determined to be a VIE,
provide your analysis
              under ASC 810-10 supporting your determination that you do not
have a controlling
              financial interest in the VIE. Address the following as part of
your response:
                o   Identify the activities of Tisento Parent that most
significantly impact its
                    economic performance and explain how you determined that
you do not have
                    the power to direct such activities and therefore do not
hold a controlling
                    financial interest.
                o   To the extent that the power is shared among the variable
interest holders,
                    clarify whether there is a tie-breaking mechanism in place
with respect to key
                    decision making.
                o   With respect to investments held by your CEO and any other
related parties,
                    provide an analysis under ASC 810-10-25-42 through 25-44B.
                o   Provide us with a copy of the Asset Purchase Agreement to
assist us with our
             Confirm that you will revise your future filings to provide the
              disclosures required by ASC 810-10-50, to the extent applicable.

       In closing, we remind you that the company and its management are
responsible for the
accuracy and adequacy of their disclosures, notwithstanding any review,
comments, action or
absence of action by the staff.

       Please contact Li Xiao at 202-551-4391 or Angela Connell at 202-551-3426
with any


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