Aclaris Therapeutics Initiates Phase 2 Trial of Bosakitug for Atopic Dermatitis

Aclaris Therapeutics has initiated a Phase 2 trial of bosakitug for moderate-to-severe atopic dermatitis, with top-line results expected in H2 2026.

Wayne, PA - June 2, 2025 - Aclaris Therapeutics, Inc. (NASDAQ: ACRS), a clinical-stage biopharmaceutical company, has initiated a randomized, double-blind, placebo-controlled Phase 2 trial of bosakitug (ATI-045) in patients with moderate-to-severe atopic dermatitis (AD). The trial is designed to evaluate the efficacy and safety of bosakitug, an investigational humanized monoclonal antibody targeting thymic stromal lymphopoietin (TSLP).

The Phase 2 trial will enroll approximately 90 patients and will assess bosakitug's ability to improve Eczema Area and Severity Index (EASI) scores, validated Investigator Global Assessment (IGA) responses, and other relevant endpoints compared to a placebo. The primary endpoint is the percent change from baseline in EASI at week 24. Secondary endpoints include EASI responses (EASI-50, EASI-75, EASI-90), BSA response, and Peak Pruritus Numerical Rating Scale (PP-NRS) score.

Bosakitug has demonstrated strong efficacy in a single-arm Phase 2a trial, with 94% of participants achieving EASI-75 scores and 88% showing clear or nearly clear skin at week 26. The company expects to provide top-line results from the Phase 2 trial in the second half of 2026.

Atopic dermatitis (AD) is a common skin condition affecting approximately 10 million children and 17 million adults in the United States, with over 200 million people worldwide. The disease can significantly impact patients' quality of life, with moderate-to-severe symptoms affecting 40% of AD patients.

Aclaris Therapeutics focuses on developing novel product candidates for immuno-inflammatory diseases. Bosakitug has the potential to treat various atopic, immunologic, and respiratory diseases due to its unique TSLP binding characteristics and high affinity.

[1] https://investor.aclaristx.com/news-releases/news-release-details/aclaris-therapeutics-initiates-phase-2-trial-bosakitug-ati-045
[2] https://www.marketscreener.com/quote/stock/ACLARIS-THERAPEUTICS-INC-26123625/news/Aclaris-Therapeutics-Inc-Initiates-Phase-2-Trial-of-Bosakitug-ATI-045-in-Atopic-Dermatitis-50131211/
[3] https://www.biospace.com/press-releases/aclaris-therapeutics-initiates-phase-2-trial-of-bosakitug-ati-045-in-atopic-dermatitis