Aclaris Therapeutics Added to the NASDAQ Biotechnology Index (NBI)

Aclaris Therapeutics, Inc. (NASDAQ: ACRS), a clinical-stage biopharmaceutical company focused on developing novel product candidates for immuno-inflammatory diseases, today announced it has been added to the Nasdaq Biotechnology Index (NASDAQ: NBI), effective at the close of trading today, December 19, 2025.

The NBI is designed to track the performance of a set of securities listed on The Nasdaq Stock Market ® that are classified as either biotechnology or pharmaceutical according to the Industry Classification Benchmark. Companies in the NBI must meet eligibility requirements, including minimum market capitalization, average daily trading volume and seasoning as a public company, among other criteria. The NBI is evaluated annually in December and is calculated under a modified capitalization-weighted methodology.

For more information about the Nasdaq Biotechnology Index, please visit this link .

About Aclaris Therapeutics, Inc.

Aclaris Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing a pipeline of novel product candidates to address the needs of patients with immuno-inflammatory diseases who lack satisfactory treatment options. The company has a multi-stage portfolio of product candidates powered by a robust R&D engine. For additional information, please visit www.aclaristx.com and follow Aclaris on X (formerly Twitter) at @AclarisTx and on LinkedIn .

Aclaris Therapeutics Contact:

Will Roberts Senior Vice President Corporate Communications and Investor Relations (484) 329-2125 [email protected]