WAYNE, PA — Aclaris Therapeutics, Inc. (Nasdaq: ACRS) reported full results from a Phase 1a clinical trial of its ATI-052 antibody and outlined plans to advance multiple programs, including selecting lichen planus as the lead indication for its ATI-2138 candidate.
The Phase 1a first-in-human study evaluated ATI-052, an investigational bispecific antibody targeting TSLP and IL-4Rα, in healthy adults through single and multiple ascending dose cohorts.
The company said ATI-052 demonstrated an estimated half-life of about 45 days and showed dose-proportional pharmacokinetics across tested levels, including increases in peak concentration and overall exposure.
Pharmacodynamic data showed sustained inhibition of biomarkers associated with inflammation, including CCL17/TARC, through at least 20 weeks for TSLP-stimulated activity and 12 weeks for IL-4-stimulated activity in higher-dose cohorts.
The company said the results support the potential for dosing intervals of up to three months.
ATI-052 was reported to be well tolerated across all cohorts, with no significant safety signals observed, including no reported cases of conjunctivitis. The study also found no impact from anti-drug antibodies on pharmacokinetics or pharmacodynamics.
The randomized, placebo-controlled Phase 1a trial included four single-dose cohorts and two multiple-dose cohorts, each with eight participants randomized 3:1 to receive ATI-052 or placebo. Participants were monitored for safety for up to 20 weeks.
Enrollment and dosing are ongoing in two Phase 1b proof-of-concept trials evaluating ATI-052 in patients with atopic dermatitis and asthma. The company expects top-line results from both studies in the second half of 2026.
Based on current data, Aclaris plans to initiate a Phase 2b program for ATI-052, initially targeting asthma, in the fourth quarter of 2026.
Separately, the company said it selected lichen planus as the lead indication for ATI-2138, an investigational oral inhibitor targeting ITK and JAK3 pathways involved in T-cell activation.
Aclaris plans to launch a multi-part Phase 2b study of ATI-2138 in lichen planus in the second half of 2026, beginning with erosive mucosal and cutaneous forms, followed by lichen planopilaris.
Lichen planus is a chronic inflammatory condition affecting an estimated 0.1% to 1.0% of the population, with symptoms including sores, pain, itching, and hair loss. The company said no therapies are currently approved by the U.S. Food and Drug Administration for the condition.
Dr. Johann Gudjonsson of the University of Michigan said the disease presents a significant burden for patients and that additional treatment options are needed to address both symptoms and underlying disease mechanisms.
Aclaris develops therapies for immuno-inflammatory diseases, including biologics and oral inhibitors targeting immune pathways.
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