Efficacy and Safety of ATTO-1310 in the Treatment of Participants With Chronic Pruritus of Unknown Origin

NCT07833306 | Not Yet Recruiting Phase 2 DMC FDA Drug

• 2 other identifiers: ATTO-1310-2012026-527672-93
• Study Type: interventional
• Target: 300
• Locations: 0 countries
• Sites: N/A

Brief Summary

The goal of this clinical trial is to assess the efficacy and safety of ATTO-1310 in patients with chronic pruritus/itch of unknown origin. The main questions it aims to answer are: Does ATTO-1310 treatment alleviate symptoms of itch in participants with chronic pruritus/itch? What medical problems do participants have when taking ATTO-1310 for 24 weeks? Researchers will compare ATTO-1310 to a placebo (a look-alike substance that contains no drug). Participants will be dosed with ATTO-1310 or a placebo, visit the clinic for checkups and tests, and keep a diary of their symptoms.

Conditions

Chronic Pruritus of Unknown Origin

Keywords

pruritus; CPUO; itch; itchy

Outcome Measures

Primary Outcomes (1)

• ≥4-point improvement from baseline in Worst Itch Numerical Rating Scale (WI-NRS) at Week 12 (WI-NRS4 response)

  Participants achieved a response if their WI-NRS improved 4 or more points from baseline on a scale ranging from zero (no itch) to 10 (worst possible itch). The baseline is calculated as the average in the final week prior to Day 1. The WI-NRS4 response endpoint at Week 12 is calculated as the average of the daily WI-NRS during Week 12 visit relative to the baseline average WI-NRS.

  Baseline and Week 12

Secondary Outcomes (19)

• WI-NRS4 response at Week 4

  Baseline and Week 4

• ≥5-point improvement from baseline in WI-NRS (WI-NRS5 response) at Week 4

  Baseline and Week 4

• ≥5-point improvement from baseline in WI-NRS (WI-NRS5 response) at Week 12

  Baseline and Week 12

• WI-NRS <2 (WI-NRS<2 response) at Week 4

  Week 4

• WI-NRS <2 (WI-NRS<2 response) at Week 12

  Week 12

Study Arms (7)

ATTO-1310 Dose A

EXPERIMENTAL

ATTO-1310 high dose induction

Drug: ATTO-1310

ATTO-1310 Dose B

EXPERIMENTAL

ATTO-1310 low dose induction

Drug: ATTO-1310

Placebo

EXPERIMENTAL

Placebo induction

Drug: Placebo

ATTO-1310 Dose C

EXPERIMENTAL

ATTO-1310 high dose high frequency maintenance

Drug: ATTO-1310

ATTO-1310 Dose D

EXPERIMENTAL

ATTO-1310 high dose low frequency maintenance

Drug: ATTO-1310

ATTO-1310 Dose E

EXPERIMENTAL

ATTO-1310 low dose high frequency maintenance

Drug: ATTO-1310

ATTO-1310 dose F

EXPERIMENTAL

ATTO-1310 low dose low frequency maintenance

Drug: ATTO-1310

Interventions

ATTO-1310 DRUG

ATTO-1310

ATTO-1310 Dose A; ATTO-1310 Dose B; ATTO-1310 Dose C; ATTO-1310 Dose D; ATTO-1310 Dose E; ATTO-1310 dose F

Placebo DRUG

Placebo preparation to match ATTO-1310 dose

Placebo

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 18 to 90 years with a body weight of 50 to 125 kg and body mass index (BMI) between 18.5 and 40 kg/m\^2.
• History of chronic pruritus for at least 6 months that is considered of unknown origin (without a clear association to another condition or medication) as assessed by the Investigator.
• Chronic pruritus must affect at least 2 of the following body areas: legs, arms, or trunk.
• History of inadequate control of pruritus with at least 1 antihistamine within 6 months of Screening.
• Patient Global Impression of Severity (PGI-S) of pruritus of "severe" at Screening.
• Use of a stable dose of topical bland emollient twice daily for at least 2 weeks immediately before Day 1
• Weekly mean of daily WI-NRS ≥7 at Day 1
• Negative pregnancy test

You may not qualify if:

• Known condition, other than dry skin, that is considered by the Investigator to be the primary cause of chronic pruritus, including: Presence of a primary dermatologic condition associated with pruritic skin lesions, regional neuropathic pruritus with the exception of peripheral small fiber neuropathy, severe renal failure, hepatobiliary disease, recent infectious dermatoses, suspected somatoform pruritus, ongoing drug-induced pruritus, malignancy or hemopathy, uncontrolled endocrine disease,
• Liver function tests (bilirubin, AST, ALT, alkaline phosphatase) \>2.5 times above the upper limit of normal
• Estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m²
• History of malignancy within 5 years of Screening
• History of severe or uncontrolled asthma
• History of known primary immunodeficiency, is considered immunocompromised, or has been treated for a parasitic infection in the past 6 months.
• History of attempted suicide within the past 2 years.
• History of hypersensitivity (including anaphylaxis) to a biologic medication, vaccine, an immunoglobulin product (plasma-derived or recombinant, eg, monoclonal antibody), or to any of the IP excipients
• Active hepatitis B virus (HBV) or hepatitis C virus (HCV) or is positive for HIV.
• Active or untreated latent tuberculosis (TB) infection.
• Any infection requiring treatment with oral or parenteral antibiotics, antivirals, antiparasitics, or antifungals within 2 weeks before Day 1.
• History of drug or alcohol abuse within 1 year of Screening

Sponsors & Collaborators

• Attovia Therapeutics Inc: lead

MeSH Terms

Conditions

Pruritus

Condition Hierarchy (Ancestors)

Skin Diseases; Skin and Connective Tissue Diseases; Skin Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Hubert Chen, MD

  Attovia Therapeutics Inc

  STUDY DIRECTOR

Central Study Contacts

Malinda Longphre

CONTACT

15105203361; mlongphre@attovia.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Randomized, Double-Blind, Placebo-Controlled; Randomization to 12 week Induction treatment regimen followed by re-randomization to Maintenance treatment regimen

Study Record Dates

• First Submitted: September 16, 2026
• First Posted: September 22, 2026
• Study Start (Estimated): December 21, 2026
• Primary Completion (Estimated): August 30, 2028
• Study Completion (Estimated): October 30, 2028
• Last Updated: September 22, 2026

Record last verified: 2026-09