X0508 4 2024-03-01 0 0001557746 Aclaris Therapeutics, Inc. ACRS 0001304113 Powell Andrew Kenneth William C/O ACLARIS THERAPEUTICS, INC. 701 LEE ROAD, SUITE 103 WAYNE PA 19087 1 0 0 0 0 Common Stock 2024-03-01 4 P 0 8500 1.23 A 22863 D Common Stock 2024-03-04 4 P 0 6000 1.25 A 28863 D The price reported is a weighted average purchase price. The shares were purchased in multiple transactions at prices ranging from $1.230 to $1.2393, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported is a weighted average purchase price. The shares were purchased in multiple transactions at prices ranging from $1.230 to $1.269, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. /s/ Mark Ballantyne, Attorney-in-Fact 2024-03-05