X0306 4 2019-03-01 0 0001557746 Aclaris Therapeutics, Inc. ACRS 0001654450 Ruffo Frank C/O ACLARIS THERAPEUTICS, INC. 640 LEE ROAD, SUITE 200 WAYNE PA 19087 0 1 0 0 Chief Financial Officer Restricted stock units 2019-03-01 4 A 0 103000 0.00 A Common Stock 103000 103000 D Each restricted stock unit represents a contingent right to receive one share of common stock of the issuer. The shares underlying these restricted stock units vest in four equal annual installments beginning on March 1, 2020, subject to the Reporting Person's continuous service with the issuer as of the applicable vesting date. /s/ Mark Ballantyne, Attorney-in-fact 2019-03-04