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 * Ruffo Frank   2. Issuer Name and Ticker or Trading Symbol Aclaris Therapeutics, Inc. [ACRS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Financial Officer (Last) (First) (Middle) C/O ACLARIS THERAPEUTICS, INC., 101 LINDENWOOD DRIVE, SUITE 400 3. Date of Earliest Transaction (Month/Day/Year) 12/15/2017 (Street) MALVERN, PA 19355 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 12/15/2017   M   1,300 A (1) 144,872 D   Common Stock 12/15/2017   F(2)   395 D $ 24.23 144,477 D   Common Stock 12/18/2017   M   1,250 A (1) 145,727 D   Common Stock 12/18/2017   F(2)   380 D $ 24.12 145,347 D

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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 Units

(1)

12/15/2017

M

1,300

(3)

(3)

Common Stock

1,300

$ 0

9,100

D

Restricted Stock Units

(1)

12/18/2017

M

1,250

(4)

(4)

Common Stock

1,250

$ 0

2,500

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Ruffo Frank C/O ACLARIS THERAPEUTICS, INC. 101 LINDENWOOD DRIVE, SUITE 400 MALVERN, PA 19355			Chief Financial Officer

Signatures

/s/ Brian F. Leaf, Attorney-in-fact		12/21/2017
**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)	Restricted stock units convert into common stock on a one-for-one basis.
(2)	The transaction reported represents the withholding of shares by the issuer to satisfy the reporting person's tax withholding obligations in connection with the vesting and settlement of the restricted stock units being reported in this Form 4.
(3)	On December 15, 2016, the reporting person was granted 10,400 restricted stock units, with 50% of the shares underlying the restricted stock units vesting in four equal annual installments beginning on December 15, 2017 and the other 50% of the shares underlying these restricted stock units vesting upon the achievement of a specified commercial milestone, subject to the reporting person's continuous service with the issuer as of the applicable vesting date.
(4)	On December 18, 2015, the reporting person was granted 5,000 restricted stock units, vesting in four equal annual installments beginning on December 18, 2016, subject to the reporting person's continuous service with the issuer as of the applicable vesting date.

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