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* Flagship Ventures Fund 2007, L.P. (Last) (First) (Middle) ONE MEMORIAL DRIVE 7TH FLOOR (Street) CAMBRIDGE MA 02142 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 07/23/2013	3. Issuer Name and Ticker or Trading Symbol AGIOS PHARMACEUTICALS INC [ AGIO ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) 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)

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	(1)	(1)	Common Stock	3,636,362	(1)	D(2)
Series C-2 Convertible Preferred Stock	(3)	(3)	Common Stock	224,374	(3)	D(2)

1. Name and Address of Reporting Person* Flagship Ventures Fund 2007, L.P. (Last) (First) (Middle) ONE 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) ONE MEMORIAL DRIVE 7TH FLOOR (Street) CAMBRIDGE MA 02142 (City) (State) (Zip)

1. Name and Address of Reporting Person* AFEYAN NOUBAR (Last) (First) (Middle) ONE 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) ONE MEMORIAL DRIVE 7TH FLOOR (Street) CAMBRIDGE MA 02142 (City) (State) (Zip)

Explanation of Responses:

1. The Series A Convertible Preferred Stock is convertible into Common Stock on a 1-for-2.75 basis into the number of shares of Common Stock as shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date.

2. These shares are 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 the shares except to the extent of any pecuniary interest therein.

3. The Series C-2 Convertible Preferred Stock is convertible into Common Stock on a 1-for-2.75 basis into the number of shares of Common Stock as shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date.

Remarks:

	By: /s/ Noubar B. Afeyan Ph. D., for Flagship Ventures Fund 2007, L.P. as Manager of Flagship Ventures 2007 General Partner LLC, its General Partner	07/23/2013
	By: /s/ Noubar B. Afeyan Ph. D., as Manager of Flagship Ventures 2007 General Partner LLC	07/23/2013
	By: /s/ Noubar B. Afeyan Ph. D.	07/23/2013
	By: /s/ Edwin M. Kania, Jr.	07/23/2013
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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