SC 13G

 

 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

 

 

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.     )*

 

 

Sigilon Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.001 par value per share

(Title of Class of Securities)

82657L 10 7

(CUSIP Number)

December 31, 2020

(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)

☐ 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. 82657L 10 7    Page 2 of 14 Pages

 

  1    

  NAMES OF REPORTING PERSONS

  I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

 

  Flagship Ventures Fund V, L.P.

  2  

  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

  (a)  ☐        (b)  ☒

 

  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

 

  0

   6   

  SHARED VOTING POWER

 

  8,888,888

   7   

  SOLE DISPOSITIVE POWER

 

  0

   8   

  SHARED DISPOSITIVE POWER

 

  8,888,888

  9    

  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 

  8,888,888

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

 

  28.5%

12  

  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

 

  PN


CUSIP No. 82657L 10 7    Page 3 of 14 Pages

 

  1    

  NAMES OF REPORTING PERSONS

  I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

 

  Flagship Ventures Fund V General Partner LLC

  2  

  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

  (a)  ☐        (b)  ☒

 

  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

 

  0

   6   

  SHARED VOTING POWER

 

  8,888,888

   7   

  SOLE DISPOSITIVE POWER

 

  0

   8   

  SHARED DISPOSITIVE POWER

 

  8,888,888

  9    

  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 

  8,888,888

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

 

  28.5%

12  

  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

 

  OO


CUSIP No. 82657L 10 7    Page 4 of 14 Pages

 

  1    

  NAMES OF REPORTING PERSONS

  I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

 

  Flagship Pioneering Special Opportunities Fund II, L.P.

  2  

  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

  (a)  ☐        (b)  ☒

 

  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

 

  0

   6   

  SHARED VOTING POWER

 

  1,481,481

   7   

  SOLE DISPOSITIVE POWER

 

  0

   8   

  SHARED DISPOSITIVE POWER

 

  1,481,481

  9    

  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 

  1,481,481

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

 

  4.7%

12  

  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

 

  PN


CUSIP No. 82657L 10 7    Page 5 of 14 Pages

 

  1    

  NAMES OF REPORTING PERSONS

  I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

 

  Flagship Pioneering Special Opportunities Fund II General Partner LLC

  2  

  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

  (a)  ☐        (b)  ☒

 

  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

 

  0

   6   

  SHARED VOTING POWER

 

  1,481,481

   7   

  SOLE DISPOSITIVE POWER

 

  0

   8   

  SHARED DISPOSITIVE POWER

 

  1,481,481

  9    

  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 

  1,481,481

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

 

  4.7%

12  

  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

 

  OO


CUSIP No. 82657L 10 7    Page 6 of 14 Pages

 

  1    

  NAMES OF REPORTING PERSONS

  I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

 

  Flagship Pioneering, Inc.

  2  

  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

  (a)  ☐        (b)  ☒

 

  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

 

  0

   6   

  SHARED VOTING POWER

 

  1,481,481

   7   

  SOLE DISPOSITIVE POWER

 

  0

   8   

  SHARED DISPOSITIVE POWER

 

  1,481,481

  9    

  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 

  1,481,481

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

 

  4.7%

12  

  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

 

  CO


CUSIP No. 82657L 10 7    Page 7 of 14 Pages

 

  1    

  NAMES OF REPORTING PERSONS

  I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

 

  Noubar B. Afeyan, Ph.D.

  2  

  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)

  (a)  ☐        (b)  ☒

 

  3  

  SEC USE ONLY

 

  4  

  CITIZENSHIP OR PLACE OF ORGANIZATION

 

  United States of America

NUMBER OF

SHARES

 BENEFICIALLY 

OWNED BY

EACH

REPORTING

PERSON

WITH:

   5     

  SOLE VOTING POWER

 

  0

   6   

  SHARED VOTING POWER

 

  10,370,369

   7   

  SOLE DISPOSITIVE POWER

 

  0

   8   

  SHARED DISPOSITIVE POWER

 

  10,370,369

  9    

  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 

  10,370,369

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

 

  33.2%

12  

  TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)

 

  IN


CUSIP No. 82657L 10 7    Page 8 of 14 Pages

 

Item 1(a).

Name of Issuer:

Sigilon Therapeutics, Inc. (the “Issuer”)

 

Item 1(b).

Address of Issuer’s Principal Executive Offices:

100 Binney Street

Cambridge, MA 02142

 

Item 2(a).

Names of Persons Filing:

The names of the persons filing this report (collectively, the “Reporting Persons”) are:

Flagship Ventures Fund V, L.P. (“Flagship Fund V”)

Flagship Ventures Fund V General Partner LLC (“Flagship V GP”)

Flagship Pioneering Special Opportunities Fund II, L.P. (“Flagship Opportunities Fund II”)

Flagship Pioneering Special Opportunities Fund II General Partner LLC (“Opportunities Fund II GP”)

Flagship Pioneering, Inc. (“Flagship Pioneering”)

Noubar B. Afeyan, Ph.D. (“Dr. Afeyan”)

 

Item 2(b).

Address of Principal Business Office or, if None, Residence:

The address of the principal business office of each of the Reporting Persons is:

c/o Flagship Pioneering Inc.

55 Cambridge Parkway, Suite 800E

Cambridge, Massachusetts 02142

 

Item 2(c).

Citizenship:

 

Flagship Fund V    Delaware
Flagship V GP    Delaware
Flagship Opportunities Fund II    Delaware
Opportunities Fund II GP    Delaware
Flagship Pioneering    Delaware
Dr. Afeyan    United States of America

 

Item 2(d).

Title of Class of Securities:

Common Stock, $0.001 par value per share (“Common Stock”).

 

Item 2(e).

CUSIP Number:

82657L 10 7

 

Item 3.

If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

Not applicable.


CUSIP No. 82657L 10 7    Page 9 of 14 Pages

 

Item 4.

Ownership.

The information required by this item with respect to each Reporting Person is set forth in Rows 5 through 9 and 11 of the cover page to this Schedule 13G. The ownership percentages reported are based on 31,240,271 shares of outstanding Common Stock, as reported in the Issuer’s Form 424(b)(4) prospectus filed with the Securities and Exchange Commission on December 7, 2020 (after full exercise of the underwriters’ option to purchase additional shares).

Flagship V GP is the general partner of Flagship Fund V, and, as such, may be deemed to beneficially own the shares beneficially owned by Flagship Fund V.

Dr. Afeyan is the manager of Flagship V GP and, as such, may be deemed to beneficially own shares beneficially owned by Flagship V GP.

Opportunities Fund II GP is the general partner of Flagship Opportunities Fund II and, as such, may be deemed to beneficially own the shares beneficially owned by Flagship Opportunities Fund II.

Flagship Pioneering is the manager of Opportunities Fund II GP and, as such, may be deemed to beneficially own the shares beneficially owned by Opportunities Fund II GP.

Dr. Afeyan is the Chief Executive Officer, sole stockholder and director of Flagship Pioneering and, as such, may be deemed to beneficially own shares beneficially owned by Flagship Pioneering.

 

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 Persons have ceased to be the beneficial owner of more than five 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 SubsidiaryWhich Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

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.

Not applicable.

Material Filed as Exhibits.

Exhibit 1 – Agreement regarding filing of joint Schedule 13G.


CUSIP No. 82657L 10 7    Page 10 of 14 Pages

 

SIGNATURE

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Date: February 16, 2021

 

FLAGSHIP VENTURES FUND V, L.P.
By:   Flagship Ventures Fund V General Partner LLC
  General Partner
  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    Manager
FLAGSHIP VENTURES FUND V GENERAL PARTNER LLC
  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    Manager
FLAGSHIP PIONEERING SPECIAL OPPORTUNITIES FUND II, L.P.
By:  

Flagship Pioneering Special Opportunities Fund II General Partner LLC

General Partner

  By: Flagship Pioneering, Inc.,
  Manager
  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    CEO, Sole Stockholder & Director
FLAGSHIP PIONEERING SPECIAL OPPORTUNITIES FUND II GENERAL PARTNER LLC
By:   Flagship Pioneering, Inc.
  Manager
  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    CEO, Sole Stockholder & Director


CUSIP No. 82657L 10 7    Page 11 of 14 Pages

 

FLAGSHIP PIONEERING, INC.

By:

 

/s/ Noubar B. Afeyan, Ph.D.

 

Noubar B. Afeyan, Ph.D.

 

CEO, Sole Stockholder & Director

/s/ Noubar B. Afeyan, Ph.D.

Noubar B. Afeyan, Ph.D.


CUSIP No. 82657L 10 7    Page 12 of 14 Pages

 

EXHIBIT 1

AGREEMENT

The persons below hereby agree that the Schedule 13G to which this agreement is attached as an exhibit, as well as all future amendments to such Schedule 13G, shall be filed on behalf of each of them. This agreement is intended to satisfy the requirements of Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934.

Date: February 16, 2021

 

FLAGSHIP VENTURES FUND V, L.P.
By:   Flagship Ventures Fund V General Partner LLC
  General Partner
  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    Manager
FLAGSHIP VENTURES FUND V GENERAL PARTNER LLC
  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    Manager
FLAGSHIP PIONEERING SPECIAL OPPORTUNITIES FUND II, L.P.
By:  

Flagship Pioneering Special Opportunities Fund II General Partner LLC

General Partner

 

By: Flagship Pioneering, Inc.,

Manager

  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    CEO, Sole Stockholder & Director
FLAGSHIP PIONEERING SPECIAL OPPORTUNITIES FUND II GENERAL PARTNER LLC
By:   Flagship Pioneering, Inc.
  Manager
  By:  

/s/ Noubar B. Afeyan, Ph.D.

    Noubar B. Afeyan, Ph.D.
    CEO, Sole Stockholder & Director


CUSIP No. 82657L 10 7    Page 13 of 14 Pages

 

FLAGSHIP PIONEERING, INC.
By:  

/s/ Noubar B. Afeyan, Ph.D.

  Noubar B. Afeyan, Ph.D.
  CEO, Sole Stockholder & Director

/s/ Noubar B. Afeyan, Ph.D.

Noubar B. Afeyan, Ph.D.