X0306 4 2022-03-01 0 0001557746 Aclaris Therapeutics, Inc. ACRS 0001604457 Walker Neal C/O ACLARIS THERAPEUTICS, INC. 640 LEE ROAD, SUITE 200 WAYNE PA 19087 1 1 0 0 President and CEO Common Stock 2022-03-01 4 M 0 96150 A 1335537 D Common Stock 2022-03-01 4 M 0 18275 A 1353812 D Common Stock 2022-03-02 4 M 0 18254 A 1372066 D Employee Stock Option (Right to Buy) 14.94 2022-03-01 4 A 0 336100 0.00 A 2032-02-29 Common Stock 336100 336100 D Restricted stock units 2022-03-01 4 A 0 96000 0.00 A Common Stock 96000 96000 D Restricted stock units 2022-03-01 4 M 0 96150 0.00 D Common Stock 96150 96150 D Restricted stock units 2022-03-01 4 M 0 18275 0.00 D Common Stock 18275 54825 D Restricted stock units 2022-03-02 4 M 0 18254 0.00 D Common Stock 18254 36508 D Each restricted stock unit represents a contingent right to receive one share of common stock of the issuer. Exercisable with respect to 25% of the shares subject to the option vesting in four equal annual installments beginning on March 1, 2023, subject to Reporting Person's continuous service as an officer with the issuer as of the applicable vesting date. The shares underlying these restricted stock units vest in four equal annual installments beginning on March 1, 2023, subject to the Reporting Person's continuous service as an officer with the issuer as of the applicable vesting date. 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. The shares underlying these restricted stock units vest in four equal annual installments beginning on March 1, 2022, subject to the Reporting Person's continuous service with the issuer as of the applicable vesting date. The shares underlying these restricted stock units vest in four equal annual installments beginning on March 2, 2021, subject to the Reporting Person's continuous service with the issuer as of the applicable vesting date. /s/ Mark Ballantyne, Attorney-in-fact 2022-03-03