Aclaris Therapeutics Reports Positive Phase 1a Results for Bispecific Antibody ATI-052, Accelerating Development Timeline
核心洞察
Aclaris Therapeutics (搜索) announced positive interim results from its Phase 1a trial of ATI-052 (搜索), an anti-TSLP (搜索)/IL-4Rα (搜索) bispecific antibody, demonstrating strong safety profile and dose-proportional pharmacokinetics up to 720 mg.
The drug showed robust target engagement and near complete target occupancy at very low doses, with at least a 26-day effective half-life supporting potential quarterly dosing intervals.
Based on these results, the company plans to initiate Phase 1b proof-of-concept trials in atopic dermatitis (搜索) and asthma (搜索) in Q1 2026, with Phase 2b planning underway for the second half of 2026.
Aclaris Therapeutics (搜索) has reported encouraging interim results from its first-in-human Phase 1a trial of ATI-052 (搜索), a novel bispecific antibody targeting both TSLP (搜索) and IL-4Rα (搜索) pathways for inflammatory diseases. The positive safety and pharmacokinetic data have prompted the company to accelerate its clinical development timeline, with proof-of-concept trials in atopic dermatitis (搜索) and asthma (搜索) expected to begin in the first quarter of 2026.
Strong Safety Profile Across Dose Range
The randomized, blinded, placebo-controlled Phase 1a study evaluated single ascending doses (SAD) and multiple ascending doses (MAD) of subcutaneously administered ATI-052 (搜索) in healthy adults. In the SAD portion, 32 volunteers were randomized 3:1 across four cohorts to receive single doses of 30, 120, 360, or 720 mg of ATI-052 or placebo. The MAD portion included 16 volunteers randomized 3:1 to receive five doses of either 240 or 480 mg administered every seven days.
ATI-052 (搜索) demonstrated a favorable safety profile across all dose levels up to 720 mg. Treatment-emergent adverse events were predominantly Grade 1, with no Grade 3 events related to the study drug or serious adverse events reported. The most common adverse event was injection site redness, which was self-resolving and generally mild. Notably, no conjunctivitis was observed in any cohort, addressing a potential concern given the drug's mechanism of action.
Promising Pharmacokinetic and Pharmacodynamic Profile
The trial revealed dose-proportional pharmacokinetics across the tested range, with approximately proportional increases in maximum peak concentration (Cmax) and area under the curve (AUC). ATI-052 (搜索) exhibited at least a 26-day effective half-life, supporting its potential best-in-class pharmacokinetic profile.
Pharmacodynamic results from the first three SAD cohorts validated ATI-052 (搜索)'s potency, showing robust target engagement and near complete target occupancy at very low doses. At the lowest tested dose of 30 mg, the drug demonstrated robust concentration-dependent inhibition of IL-4 (搜索) and TSLP (搜索) stimulated CCL17/TARC. At 120 mg, complete and sustained inhibition was observed through week one, with near complete inhibition of TSLP stimulated CCL17/TARC lasting at least three weeks. The 360 mg dose showed complete inhibition through week three, with near complete inhibition persisting for at least six weeks.
Accelerated Development Timeline
"ATI-052 (搜索) demonstrated a strong safety and tolerability profile, dose proportional pharmacokinetic profile, and concentration-dependent pharmacodynamics even at the lowest dose – all of which support its best-in-class potential in a variety of inflammatory and immunological diseases," said Dr. Neal Walker, Chief Executive Officer of Aclaris.
The combination of prolonged pharmacokinetic duration and sustained pharmacodynamic effects supports the potential for dosing intervals of up to every three months. This extended dosing schedule could represent a significant advantage in patient compliance and treatment convenience.
Based on these positive results, Aclaris expects to initiate a Phase 1b proof-of-concept trial in atopic dermatitis (搜索) imminently and a Phase 1b trial in asthma (搜索) during the first quarter of 2026. The company anticipates topline data from both trials in the second half of 2026. Planning is already underway for a Phase 2b trial in atopic dermatitis expected to begin in the second half of 2026.
Novel Dual-Target Mechanism
ATI-052 (搜索) is an investigational humanized bispecific antibody that exhibits high binding affinity to both thymic stromal lymphopoietin (TSLP (搜索)) and interleukin-4 receptor alpha (IL-4Rα (搜索)). The drug targets TSLP at the top of the inflammatory cascade while simultaneously blocking IL-4Rα, thereby inhibiting both downstream IL-4 (搜索) and IL-13 (搜索) cytokines involved in Th2-mediated inflammation and allergic diseases.
The antibody utilizes the same TSLP (搜索) antigen-binding fragment region as bosakitug (ATI-045), retaining advantages in dissociation kinetics, long residence time, and high potency compared to other antibodies. However, ATI-052 (搜索) is engineered to bind more tightly to the neonatal Fc receptor (FcRn), potentially extending its half-life beyond existing therapies.
Aclaris holds exclusive worldwide rights to ATI-052 (搜索), excluding Greater China, positioning the company to advance this potential best-in-class therapy across multiple inflammatory and immunologic conditions.