ATTO-1310 Yields 82% PP-NRS4 Itch Response at Week 12

By Daniel Okafor

At week 12, a single dose of ATTO-1310 produced an 82% (14/17) PP-NRS4 response in chronic pruritus, compared with 22% (2/9) for placebo, according to Attovia Therapeutics’ phase 1b topline results.

Attovia announced the findings on November 5, 2026. The phase 1b study examined patients with chronic pruritus and high-itch atopic dermatitis (AD), with outcomes reported through week 12. ClinicalTrials.gov lists the study as NCT06787586. All P values were nominal. Week 4 was the last visit before rescue therapy was permitted.

ATTO-1310 is a subcutaneous, anti-IL-31 ATTOBODY-based therapy. It targets the IL-31 ligand rather than the IL-31 receptor.

What did the phase 1b study show in chronic pruritus?

The chronic-pruritus cohort included 17 ATTO-1310-treated patients and nine placebo recipients. The 82% versus 22% PP-NRS4 response difference carried a nominal P value below .01.

Eight treated patients (47%) reached an itch-free or nearly itch-free state by week 12. None of the nine placebo patients reached that threshold.

The result was a single-dose signal at the end of a 12-week evaluation. Broader efficacy and longer-term benefit still require testing in larger trials.

How much did high-itch atopic dermatitis improve?

Attovia reported rapid improvement in skin disease severity that continued through week 12. The week-12 EASI percentage changes from baseline were:

• −49% with 4.5 mg/kg ATTO-1310.
• −62% with 9 mg/kg ATTO-1310.
• −28% with pooled placebo.

The pooled ATTO-1310 group included 18 patients, while the placebo group included eight. Response outcomes favored treatment across every reported threshold:

• EASI-75: 44% (8/18) with ATTO-1310 versus 13% (1/8) with placebo.
• EASI-90: 22% (4/18) versus 0% (0/8).
• EASI-100: 17% (3/18) versus 0% (0/8).
• Validated Investigator Global Assessment score of 0 or 1: 39% (7/18) versus 13% (1/8).

Response rates increased from week 4 to week 12 on all four measures. Overall, the treated group improved more than placebo at every reported skin-outcome threshold.

Was ATTO-1310 well tolerated, and could dosing stretch to a quarter?

Attovia said ATTO-1310 was generally well tolerated in healthy volunteers and patients. The safety findings were as follows:

• One healthy volunteer discontinued treatment because of a treatment-emergent adverse event (TEAE), grade 1 fever.
• No TEAEs led to discontinuation in patients with chronic pruritus or AD.
• One serious TEAE involved worsening of a preexisting hiatal hernia. The company deemed it unrelated to treatment.

Anti-drug antibodies were detected in 7.8% of healthy volunteers and patients. Attovia reported no observed effect on pharmacokinetics, target engagement, tolerability, or clinical activity.

A single dose suppressed circulating IL-31 by approximately 95% through week 12. Drug concentrations also remained above the IC90. The company said these findings support potential quarterly maintenance dosing.

At Northwell Health, Brian Kim, MD, MTR, FAAD, vice president and chief biotechnology officer, 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.”

The company reported generally good tolerability in these small cohorts. Quarterly maintenance dosing remains a potential schedule, not an established one.

What are the next steps in 2027?

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.”

Attovia plans to begin two phase 2 trials in the first half of 2027:

• ATTUNE-CPUO: Approximately 300 patients across 78 sites in North America and the European Union.
• ATTUNE-AD: Approximately 255 patients with high-itch AD across about 60 sites in North America, the European Union, and the Asia-Pacific region.

The program will now move from small phase 1b cohorts to substantially larger trials. The next test is whether those studies reproduce the week-12 itch and EASI gains and establish whether quarterly maintenance dosing is viable.