X0306 4 2019-10-30 0 0001557746 Aclaris Therapeutics, Inc. ACRS 0001751167 Gordon David N. C/O ACLARIS THERAPEUTICS, INC. 640 LEE ROAD, SUITE 200 WAYNE PA 19087 0 1 0 0 Chief Medical Officer Restricted stock units 2019-10-30 4 A 0 175000 0.00 A Common Stock 175000 175000 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 two equal annual installments beginning on June 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 2019-10-31