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 OF SECURITIES 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 * Clayman Michael 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 _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) President and CEO (Last) (First) (Middle) C/O FLEXION THERAPEUTICS, INC., 10 MALL ROAD, SUITE 301 3. Date of Earliest Transaction (Month/Day/Year) 10/06/2017 (Street) BURLINGTON, MA 01803 4. If Amendment, Date Original Filed(Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 10/06/2017   M   14,800 A (1) 36,189 D   Common Stock 10/06/2017   F   5,794 D $ 29.9349 30,395 D   Common Stock               294,383 I By the Michael D. Clayman 2006 Revocable Trust Common Stock               24,600 I By the Michael D. Clayman Irrevocable Trust Common Stock               388,683 I By Versant Development Fund III, LLC (2)

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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

Restricted Stock Unit Award

(1)

10/06/2017

M

14,800

(3)

10/06/2019

Common Stock

14,800

$ 0

29,600

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Clayman Michael D. C/O FLEXION THERAPEUTICS, INC. 10 MALL ROAD, SUITE 301 BURLINGTON, MA 01803	X		President and CEO

Signatures

/s/ Mark S. Levine, Attorney-in-Fact		10/10/2017
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock.
(2)	Shares held by Versant Development Fund III, LLC. The Reporting Person is a manager and minority member of Versant Development Fund III, LLC. The Reporting Person disclaims any beneficial ownership of the shares held by Versant Development Fund III, LLC except to the extent of his pecuniary interest in these shares.
(3)	On January 4, 2016, the reporting person was granted up to 66,600 restricted stock units. The amount and vesting of the shares under the restricted stock unit award was based on the achievement of certain milestones that were established at the time of the Compensation Committee's approval of the restricted stock unit award on December 17, 2015. On October 6, 2017, the Compensation Committee certified the achievement of a milestone under the restricted stock unit award resulting in the commencement of vesting of 44,400 shares as follows: 14,800 shares vested as of October 6, 2017, 14,800 shares vested as of October 6, 2018 and 14,800 shares vested as of October 6, 2019.

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