EXHIBIT 31.2

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Frank Ruffo, certify that:

1. I have reviewed this annual report on Form 10-K/A of Aclaris Therapeutics, Inc. (the “registrant”); and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

Date: April 25, 2016

/s/ Frank Ruffo

Frank Ruffo

Chief Financial Officer

(principal financial officer and principal accounting officer)