Sec Form 4 Filing - NELSEN ROBERT @ AGIOS PHARMACEUTICALS INC - 2017-02-21

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person NELSEN ROBERT 2. Issuer Name and Ticker or Trading Symbol AGIOS PHARMACEUTICALS INC [ AGIO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O ARCH VENTURE PARTNERS, 8755 WEST HIGGINS ROAD, SUITE 1025 3. Date of Earliest Transaction (MM/DD/YY) 02/21/2017 (Street) CHICAGO, IL60631 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/21/2017 S 1,780 D $ 54.1733 ( 1 ) 417,265 I By ARCH Venture Fund VII, L.P. ( 7 ) Common Stock 02/21/2017 S 34,650 D $ 50.5576 ( 2 ) 382,615 I By ARCH Venture Fund VII, L.P. ( 7 ) Common Stock 02/22/2017 S 46,938 D $ 49.9043 ( 3 ) 335,677 I By ARCH Venture Fund VII, L.P. ( 7 ) Common Stock 02/22/2017 S 1,000 D $ 50.3455 ( 4 ) 334,677 I By ARCH Venture Fund VII, L.P. ( 7 ) Common Stock 02/23/2017 S 42,596 D $ 47.727 ( 5 ) 292,081 I By ARCH Venture Fund VII, L.P. ( 7 ) Common Stock 02/23/2017 S 8,400 D $ 48.7478 ( 6 ) 283,681 I By ARCH Venture Fund VII, L.P. ( 7 ) Common Stock 06/30/2016 J( 8 ) 25,412 A 73,078 D Common Stock 08/08/2016 J( 8 ) 36,152 A 109,230 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other NELSEN ROBERT C/O ARCH VENTURE PARTNERS 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO, IL60631 X Signatures /s/ Robert T. Nelsen 02/23/2017 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $54.00 to $54.36. The reporting person undertakes to provide to AGIO, any security holder of AGIO, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1), (2), (3), (4), (5) and (6) to this Form 4. ( 2 )The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $50.50 to $50.74. ( 3 )The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $49.25 to $50.25. ( 4 )The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $50.255 to $50.68. ( 5 )The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $47.50 to $48.24. ( 6 )The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $48.51 to $49.06. ( 7 )These shares are owned directly by ARCH Venture Fund VII, L.P. ("ARCH Fund VII"). The sole general partner of ARCH Fund VII is ARCH Venture Partners VII, L.P. ("ARCH Partners VII"). The sole general partner of ARCH Partners VII is ARCH Venture Partners VII, LLC ("ARCH VII LLC"). The Managing Directors of ARCH VII LLC, Robert T. Nelsen, Keith Crandell and Clinton Bybee, are deemed to have voting and dispositive power over the shares and may be deemed to beneficially own certain shares held by ARCH Fund VII. Each Reporting Person disclaims beneficial ownership of these securities, except to the extent of his pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Persons are the beneficial owners of such securities for Section 16 or any other purpose. ( 8 )Distribution of Common Stock held by a limited partnership to its partners for no consideration. Change from indirect to direct ownership of shares previously reported as beneficially owned by the reporting person.

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 4(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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.