ATTO-1310 Reduces Itch at Week 12 in Chronic Pruritus and Atopic Dermatitis

Attovia Therapeutics recently announced positive topline 12-week results from its phase 1b study of ATTO-1310, an anti-interleukin 31 (IL-31) ATTOBODY-based therapy, in patients with chronic pruritus (CP) and high-itch atopic dermatitis (AD). A single subcutaneous dose reduced itch through week 12 in both populations, according to the company.¹

No FDA-approved treatments exist for chronic pruritus of unknown origin (CPUO), per investigator commentary in the release. ATTO-1310 targets the IL-31 ligand rather than its receptor. Phase 2 trials in CPUO and high-itch AD are expected to begin in the first half of 2027.¹

The randomized, double-blind, placebo-controlled, 4-part study (NCT06787586) ran across 17 sites in the US and Canada.^1,2 Phase 1b randomized patients with CP (n = 26) and high-itch AD (n = 26) to a single subcutaneous dose of ATTO-1310 at 4.5 or 9 mg/kg or placebo. Safety, pharmacokinetics, and immunogenicity were primary and secondary end points, while itch and skin outcomes were exploratory.¹

Among patients with CP, 47% of pooled ATTO-1310 recipients achieved a reduction of 4 points or more on the Peak Pruritus Numerical Rating Scale (PP-NRS4) at week 2 vs 0% with placebo (P < .05). At week 12, PP-NRS4 response reached 82% (14/17) vs 22% (2/9) with placebo (P < .01). Itch-free or nearly itch-free status (PP-NRS < 2) was achieved by 47% (8/17) vs 0% (0/9) at week 12 (P < .05).¹

In high-itch AD, 39% of ATTO-1310-treated patients achieved PP-NRS4 at week 2 vs 25% with placebo, rising to 44% (8/18) at week 4 and sustained through week 12. Pooled placebo response also rose, from 25% (2/8) at week 4 to 75% (6/8) at week 12.¹ At week 12, 28% (5/18) of ATTO-1310-treated patients reached PP-NRS < 2 vs 13% (1/8) with placebo.¹

All P values were nominal. Week 4 was the last visit before rescue therapy was permitted.¹

ATTO-1310 Skin Lesion Outcomes, Safety, and Dosing Interval Data

Skin disease severity improved rapidly and deepened through week 12 in high-itch AD.¹ Eczema Area and Severity Index (EASI) percentage change from baseline at week 12 was −49% with 4.5 mg/kg and −62% with 9 mg/kg vs −28% with pooled placebo. EASI-75 was achieved by 44% (8/18) of pooled ATTO-1310-treated patients vs 13% (1/8) with placebo.¹

At week 12, EASI-90 was reached by 22% (4/18) vs 0% (0/8), and EASI-100 by 17% (3/18) vs 0% (0/8). A validated Investigator Global Assessment score of 0 or 1 was achieved by 39% (7/18) vs 13% (1/8). Response rates increased across all 4 measures from week 4 to week 12.¹

ATTO-1310 was generally well tolerated in healthy volunteers (HV) and patients, according to the company. One HV discontinued treatment owing to a treatment-emergent adverse event (TEAE), grade 1 fever, and no TEAEs led to discontinuation in patients with CP or AD. One serious TEAE, worsening of a preexisting hiatal hernia, was deemed unrelated to treatment.¹

Anti-drug antibodies were detected in 7.8% of HV and patients, with no observed effect on pharmacokinetics, target engagement, tolerability, or clinical activity. A single dose suppressed circulating IL-31 by approximately 95% through week 12, and drug concentrations remained above the IC90. The company said these data support potential quarterly maintenance dosing.¹

Brian Kim, MD, MTR, FAAD, vice president and chief biotechnology officer at Northwell Health, said, “ATTO-1310’s strategy of targeting the IL-31 ligand rather than its receptor offers a potentially differentiated approach to achieving robust itch relief while reducing the risk of the dermatitis flares observed with receptor blockade.”¹

Jonathan Silverberg, MD, PhD, MPH, professor of dermatology at The George Washington University School of Medicine and Health Sciences, said, “Given the central role of IL-31 in driving itch, a highly effective, long-acting biologic targeting this pathway could represent an important advance in AD treatment.”¹

The ATTUNE-CPUO trial plans to enroll approximately 300 patients across 78 sites in North America and the EU. ATTUNE-AD plans to enroll approximately 255 patients with high-itch AD across approximately 60 sites in North America, the EU, and the Asia-Pacific region. Both are expected to begin in the first half of 2027.¹

References

1. Attovia Therapeutics announces positive topline 12-week results from phase 1b study of ATTO-1310 in patients with chronic pruritus and high-itch atopic dermatitis. Attovia Therapeutics. News release. November 5, 2026. Accessed November 6, 2026. https://investors.attovia.com/news-releases/news-release-details/attovia-therapeutics-announces-positive-topline-12-week-results
2. ClinicalTrials.gov identifier: NCT06787586. Accessed November 6, 2026. https://clinicaltrials.gov/study/NCT06787586