Edwin M Kania JR Form 3 Seres Therapeutics / EDWIN M KANIA JR ownership change

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

AFEYAN NOUBAR

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
06/25/2015

3. Issuer Name and Ticker or Trading Symbol
Seres Therapeutics, Inc. [ MCRB ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	3,055,556	I	See Footnote(1)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Convertible Preferred Stock	(5)	(5)	Common Stock	6,105,362	(5)	I	See Footnote(2)
Series A Convertible Preferred Stock	(5)	(5)	Common Stock	1,526,338	(5)	I	See Footnote(3)
Series A Convertible Preferred Stock	(5)	(5)	Common Stock	599,297	(5)	I	See Footnote(4)
Series A-2 Convertible Preferred Stock	(5)	(5)	Common Stock	898,877	(5)	I	See Footnote(2)
Series A-2 Convertible Preferred Stock	(5)	(5)	Common Stock	224,719	(5)	I	See Footnote(3)
Series B Convertible Preferred Stock	(5)	(5)	Common Stock	1,818,181	(5)	I	See Footnote(2)
Series B Convertible Preferred Stock	(5)	(5)	Common Stock	454,546	(5)	I	See Footnote(3)

1. Name and Address of Reporting Person^*

AFEYAN NOUBAR

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund 2007, L.P.

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund IV, L.P.

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund IV-Rx, L.P.

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship VentureLabs IV, LLC

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures 2007 General Partner LLC

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Flagship Ventures Fund IV General Partner LLC

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

KANIA EDWIN M JR

(Last) (First) (Middle)

1 MEMORIAL DRIVE, 7TH FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

Explanation of Responses:

1. Held by Flagship VentureLabs IV LLC ("Flagship VentureLabs"). Flagship Ventures Fund IV, L.P. ("Flagship Fund IV") is a member of Flagship VentureLabs and also serves as its manager. Flagship Ventures Fund IV General Partner LLC ("Flagship Fund IV GP") is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. Each of these individuals and entities may be deemed to share voting and investment power with respect to all shares held by Flagship VentureLabs. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

2. Held by Flagship Fund IV. Flagship Fund IV GP is the general partner of Flagship Fund IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship Fund IV. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

3. Held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship IV-Rx"). Flagship Fund IV GP is the general partner of Flagship IV-Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship Fund IV GP. Flagship Fund IV GP and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV-Rx. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

4. Held by Flagship Ventures Fund 2007, L.P. ("Flagship 2007"). Flagship Ventures 2007 General Partner LLC ("Flagship 2007 LLC") is the general partner of Flagship 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship 2007 LLC. Flagship 2007 LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship 2007. Each of the filing persons disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein.

5. Each class of preferred stock is convertible into Common Stock on a 1-for-1 basis upon the listing of the issuer's securities on The NASDAQ Global Select Exchange and has no expiration date.

Remarks:

	NOUBAR B. AFEYAN, PH.D, /s/ Noubar Afeyan	06/25/2015
	FLAGSHIP VENTURES FUND 2007, L.P., By: Flagship Ventures 2007 General Partner, LLC, By: /s/ Noubar Afeyan, Name: Noubar B. Afeyan, Title: Manager	06/25/2015
	FLAGSHIP VENTURES 2007 GENERAL PARTNER, LLC, By: /s/ Noubar Afeyan, Name: Noubar B. Afeyan, Title: Manager	06/25/2015
	FLAGSHIP VENTURES FUND IV, L.P., By: Flagship Ventures Fund IV General Partner, LLC, By: /s/ Noubar Afeyan, Name: Noubar B. Afeyan, Title: Manager	06/25/2015
	FLAGSHIP VENTURES FUND IV GENERAL PARTNER LLC, By: /s/ Noubar Afeyan, Name: Noubar B. Afeyan, Title: Manager	06/25/2015
	FLAGSHIP VENTURES FUND IV-RX, L.P., By: Flagship Ventures 2007 General Partner, LLC, By: /s/ Noubar Afeyan, Name: Noubar B. Afeyan, Title: Manager	06/25/2015
	FLAGSHIP VENTURELABS IV, LLC, By: Flagship Ventures Fund IV General Partner LLC, By: /s/ Noubar Afeyan	06/25/2015
	EDWIN M. KANIA, JR., /s/ Edwin Kania, Jr.	06/25/2015
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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