Sec Form 4 Filing - COLELLA SAMUEL D @ Flexion Therapeutics Inc - 2017-06-05

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

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1. Name and Address of Reporting Person COLELLA SAMUEL D 2. Issuer Name and Ticker or Trading Symbol Flexion Therapeutics Inc [ FLXN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O FLEXION THERAPEUTICS, INC., 10 MALL ROAD, SUITE 301 3. Date of Earliest Transaction (MM/DD/YY) 06/05/2017 (Street) BURLINGTON, MA01803 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 06/05/2017 P 5,000 A $ 17.0095 ( 1 ) 5,000 I By the Colella Family Exempt Marital Deduction Trust ( 2 ) Common Stock 43,333 I By the Colella Family Trust ( 3 ) Common Stock 25,504 D Common Stock 3,511,670 I See Footnote ( 4 ) Common Stock 20,739 I See Footnote ( 5 ) Common Stock 388,683 I See Footnote ( 6 )

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 COLELLA SAMUEL D C/O FLEXION THERAPEUTICS, INC. 10 MALL ROAD, SUITE 301 BURLINGTON, MA01803 X X Signatures /s/ Samuel D. Colella 06/06/2017 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The weighted average purchase price for the transaction reported was $17.0095, and the range of prices were between $16.98 and $17.06. Upon request by the SEC staff, the Issuer, or any security holder of the Issuer, full information regarding the number of shares purchased at each separate price will be provided. ( 2 )The shares are held by the Colella Family Exempt Marital Deduction Trust Dated 9/21/1992 ("Colella Exempt Trust"). The Reporting Person is a trustee and beneficiary of the Colella Exempt Trust. ( 3 )The shares are held by the Colella Family Trust UTA Dtd. 9/21/92 ("Colella Trust"). The Reporting Person is a trustee and beneficiary of the Colella Trust. ( 4 )The shares are held by Versant Venture Capital III, L.P. ("VVC III"). The Reporting Person is a managing member of Versant Ventures III, LLC ("VV III"), the sole general partner of VVC III and shares voting and dispositive power over the shares held by VVC III; however, he disclaims beneficial ownership of the shares held by such entity except to the extent of his pecuniary interests therein. ( 5 )The shares are held by Versant Side Fund III, L.P. ("Side Fund III"). The Reporting Person is a managing member of VV III, the sole general partner of Side Fund III and shares voting and dispositive power over the shares held by Side Fund III; however, he disclaims beneficial ownership of the shares held by such entity except to the extent of his pecuniary interests therein. ( 6 )The shares are held by Versant Development Fund III, LLC ("Development III"). The Reporting Person is a managing member of VV III, a majority member of Development III and shares voting and dispositive power over the shares held by Development III; however, he disclaims beneficial ownership of the shares held by such entity except to the extent of his pecuniary interests therein.

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).

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