Aclaris Therapeutics Starts Phase 2 Trial of Bosakitug for Atopic Dermatitis

Aclaris Therapeutics, Inc., a biopharmaceutical company specializing in innovative treatments for immuno-inflammatory conditions, has launched a Phase 2 clinical trial for its promising monoclonal antibody, bosakitug (ATI-045). This investigational therapy targets patients with moderate-to-severe atopic dermatitis (AD) and aims to evaluate its effectiveness and safety.

Bosakitug is positioned as a potential leading treatment due to its unique properties, such as high potency, prolonged residence time, and strong affinity to thymic stromal lymphopoietin (TSLP). TSLP is a cytokine that plays a crucial role in the immune response associated with allergic and inflammatory diseases. By blocking TSLP's interaction with receptors, bosakitug prevents the release of proinflammatory cytokines, potentially offering a new approach to treating a range of atopic and respiratory conditions.

The initiation of this trial follows promising results from a single arm Phase 2a study, where bosakitug showed significant improvements in patients with moderate-to-severe AD. Notably, 94% of participants achieved EASI-75 scores, indicating a 75% reduction in eczema severity, while 88% of participants experienced clear or nearly clear skin as measured by Investigator Global Assessment (IGA) scores of 0/1. These results underscore bosakitug’s potential as a best-in-class anti-TSLP therapy.

The current Phase 2 trial, which is randomized, double-blind, and placebo-controlled, will involve around 90 participants globally. The primary goal is to assess changes in the Eczema Area and Severity Index (EASI) at 24 weeks. Secondary measures include various EASI responses, IGA responses, body surface area changes, and itch severity scores, alongside safety and tolerability assessments. This trial aims to solidify bosakitug's efficacy and safety profile, with preliminary results expected in the latter half of 2026.

Atopic dermatitis, a prevalent form of eczema, affects millions globally. In the United States alone, it impacts approximately 27 million people, including both children and adults. The disease manifests as dry, itchy, and inflamed skin, significantly affecting life quality, especially for those with moderate-to-severe symptoms. Current statistics highlight that about 40% of AD sufferers experience moderate or severe symptoms, leading to social and sleep disruptions.

Aclaris Therapeutics is committed to addressing unmet needs in immuno-inflammatory diseases through its innovative pipeline. This Pennsylvania-based company leverages a strong research and development framework to advance its portfolio of product candidates. With exclusive global rights to bosakitug outside of Greater China, Aclaris continues to push the boundaries of treatment options for conditions like atopic dermatitis.

The development of bosakitug highlights the therapeutic potential of targeting TSLP, a central player in the immune response at the skin and respiratory barrier surfaces. By modulating this pathway, bosakitug could provide a robust treatment option for a range of allergic and inflammatory diseases, influencing not just immediate inflammatory responses but also downstream immune activities.

As the Phase 2 trial progresses, the medical community and patients alike await further insights into bosakitug’s potential to transform the treatment landscape for atopic dermatitis and other related conditions. With ongoing research and trials, Aclaris Therapeutics aims to deliver novel therapeutic solutions to patients who face limited treatment options, improving their quality of life and addressing the complex challenges of immuno-inflammatory diseases.