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, 
2023
                                                            Form 10-Q for the 
Quarterly Period Ended September 30, 2023
                                                            Filed November 13, 
2023
                                                            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.
November
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
                    review.
             Confirm that you will revise your future filings to provide the 
VIE-specific
              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
questions.



                                                                 Sincerely,

                                                                 Division of 
Corporation Finance
                                                                 Office of Life 
Sciences