UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G

Under the Securities Exchange Act of 1934
(Amendment No. __ )*
CYCLERION THERAPEUTICS, INC.
(Name of Issuer)
 
Common Shares, no par value per share
(Title of Class of Securities)
 
23255M 105
(CUSIP Number)
 
Cyclerion Therapeutics, Inc., 301 Binney Street, Cambridge, MA 02142
(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

April 2, 2019
(Date of Event which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

[   ]  Rule 13d-1(b)
[X]  Rule 13d-1(c)
[   ]  Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).



CUSIP No. 23255M 105

1
NAMES OF REPORTING PERSONS
 
MFN Partners, LP
 
 
 
2
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
 
 
(a) [   ]
(b) [X]
3
SEC USE ONLY
 
 
4
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5
SOLE VOTING POWER
 
 
1,506,852
6
SHARED VOTING POWER
 
 
0
7
SOLE DISPOSITIVE POWER
 
 
1,506,852
8
SHARED DISPOSITIVE POWER
 
 
0
9
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,506,852
10
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
 
[   ]
11
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
5.5%
12
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
 
PN


2

CUSIP No. 23255M 105


1
NAMES OF REPORTING PERSONS
 
MFN Partners GP, LLC
 
 
 
2
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
 
 
(a) [   ]
(b) [X]
3
SEC USE ONLY
 
 
4
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5
SOLE VOTING POWER
 
 
1,506,852
6
SHARED VOTING POWER
 
 
0
7
SOLE DISPOSITIVE POWER
 
 
1,506,852
8
SHARED DISPOSITIVE POWER
 
 
0
9
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,506,852
10
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
 
[   ]
11
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
5.5%
12
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
 
OO


3

CUSIP No. 23255M 105


1
NAMES OF REPORTING PERSONS
 
MFN Partners Management, LP
 
 
 
2
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
 
 
(a) [   ]
(b) [X]
3
SEC USE ONLY
 
 
4
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5
SOLE VOTING POWER
 
 
1,506,852
6
SHARED VOTING POWER
 
 
0
7
SOLE DISPOSITIVE POWER
 
 
1,506,852
8
SHARED DISPOSITIVE POWER
 
 
0
9
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,506,852
10
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
 
[   ]
11
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
5.5%
12
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
 
IA


4

CUSIP No. 23255M 105


1
NAMES OF REPORTING PERSONS
 
MFN Partners Management, LLC
 
 
 
2
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
 
 
(a) [   ]
(b) [X]
3
SEC USE ONLY
 
 
4
CITIZENSHIP OR PLACE OF ORGANIZATION
 
Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5
SOLE VOTING POWER
 
 
1,506,852
6
SHARED VOTING POWER
 
 
0
7
SOLE DISPOSITIVE POWER
 
 
1,506,852
8
SHARED DISPOSITIVE POWER
 
 
0
9
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,506,852
10
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
 
[   ]
11
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
5.5%
12
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
 
OO


5

CUSIP No. 23255M 105


1
NAMES OF REPORTING PERSONS
 
Farhad Nanji
 
 
 
2
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
 
 
(a) [   ]
(b) [X]
3
SEC USE ONLY
 
 
4
CITIZENSHIP OR PLACE OF ORGANIZATION
 
United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5
SOLE VOTING POWER
 
 
1,506,852
6
SHARED VOTING POWER
 
 
0
7
SOLE DISPOSITIVE POWER
 
 
1,506,852
8
SHARED DISPOSITIVE POWER
 
 
0
9
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,506,852
10
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
 
[   ]
11
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
5.5%
12
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
 
IN


6

CUSIP No. 23255M 105


1
NAMES OF REPORTING PERSONS
 
Michael DeMichele
 
 
 
2
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
 
 
(a) [   ]
(b) [X]
3
SEC USE ONLY
 
 
4
CITIZENSHIP OR PLACE OF ORGANIZATION
 
United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5
SOLE VOTING POWER
 
 
1,506,852
6
SHARED VOTING POWER
 
 
0
7
SOLE DISPOSITIVE POWER
 
 
1,506,852
8
SHARED DISPOSITIVE POWER
 
 
0
9
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
1,506,852
10
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)
 
[   ]
11
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
 
5.5%
12
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
 
IN




7

CUSIP No. 23255M 105


Item 1.
 
(a)
Name of Issuer:
 
Cyclerion Therapeutics, Inc.
(b)
Address of Issuer’s Principal Executive Offices:
 
301 Binney Street
Cambridge, MA 02142
Item 2.
 
(a)
This Statement on Schedule 13G is being filed on behalf of:
 
(i)
MFN Partners, LP, a Delaware limited partnership (the “Partnership”)
 
(ii)
MFN Partners GP, LLC, a Delaware limited liability company (“MFN GP”), the General Partner of the Partnership
 
(iii)
MFN Partners Management, LP, a Delaware limited partnership (“MFN Management”), the investment adviser to the Partnership
 
(iv)
MFN Partners Management, LLC, a Delaware limited liability company (“MFN LLC”), the General Partner of MFN Management
 
(v)
Farhad Nanji, in his capacities as managing member of MFN GP and MFN LLC
 
(vi)
Michael DeMichele, in his capacities as managing member of MFN GP and MFN LLC
(b)
Address of Principal Business Office or, if None, Residence:
 
c/o MFN Partners Management, LP
222 Berkeley St., 13th Floor
Boston, MA 02116
(c)
Citizenship:
 
The Partnership
Delaware
 
MFN GP
Delaware
 
MFN Management
Delaware
 
MFN LLC
Delaware
 
Farhad Nanji
United States
 
Michael DeMichele
United States
(d)
Title and Class of Securities:
 
Common stock, no par value per share
(e)
CUSIP No.:
 
23255M 105
Item 3.
For statement filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c)
 
Not applicable
Item 4.
Ownership
For the Partnership, MFN GP, MFN Management, MFN LLC, Farhad Nanji and Michael DeMichele
 
(a)
Amount beneficially owned: 1,506,852
 
(b)
Percent of Class: 5.5%
 
(c)
Number of shares as to which the person has:
   
(i)
Sole power to vote or to direct the vote: 1,506,852
   
(ii)
Shared power to vote to direct the vote: 0
   
(iii)
Sole power to dispose or to direct the disposition of: 1,506,852
   
(iv)
Shared power to dispose or to direct the disposition of: 0
Item 5.
Ownership of Five Percent or Less of a Class.
 
If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following [   ]
Item 6.
Ownership of more than Five Percent on Behalf of Another Person.
 
Not applicable
Item 7.
Identification and classification of the subsidiary which acquired the security being reported on by the parent holding company.
 
Not Applicable
Item 8.
Identification and classification of members of the group.
 
Not applicable
Item 9.
Notice of Dissolution of Group.
 
Not applicable
Item 10.
Certification.
 
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.


8

CUSIP No. 23255M 105
SIGNATURES
After reasonable inquiry and to the best of his or its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.  We also hereby agree to file this statement jointly pursuant to the agreement set forth as Exhibit 1.

 Dated: April 2, 2019
MFN PARTNERS, LP
 
     
 
By MFN Partners GP, LLC, its General Partner
 
 
 
 
 
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
MFN PARTNERS GP, LLC
 
 
 
 
 
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
MFN PARTNERS MANAGEMENT, LP
 
       
 
By MFN Partners Management, LLC, its General Partner
 
 
 
 
 
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
MFN PARTNERS MANAGEMENT, LLC
 
       
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
FARHAD NANJI
 
       
   /s/ Farhad Nanji
 
       
 
MICHAEL DEMICHELE
 
       
   /s/ Michael DeMichele
 
       


9


CUSIP No. 23255M 105

EXHIBIT INDEX

Exhibit 1.
Joint Filing Agreement as required by Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended.


10

CUSIP No. 23255M 105
Exhibit 1

JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k)(1)

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13G need be filed with respect to the ownership by each of the undersigned of shares of Common Stock of Carbon Black, Inc.

Dated: April 2, 2019
 
MFN PARTNERS, LP
 
     
 
By MFN Partners GP, LLC, its General Partner
 
 
 
 
 
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
MFN PARTNERS GP, LLC
 
 
 
 
 
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
MFN PARTNERS MANAGEMENT, LP
 
       
 
By MFN Partners Management, LLC, its General Partner
 
 
 
 
 
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
MFN PARTNERS MANAGEMENT, LLC
 
       
 
By:
/s/ Jonathan Reisman
 
 
Name:
Jonathan Reisman
 
 
Title:
Authorized Person
 
       
 
FARHAD NANJI
 
       
   /s/ Farhad Nanji
 
       
 
MICHAEL DEMICHELE
 
       
   /s/ Michael DeMichele