WESTLAKE VILLAGE, Calif. — March 3, 2026 — Leads & Copy — Arcutis Biotherapeutics, Inc. (Nasdaq: ARQT) has announced the enrollment of the first participant in a Phase 1a/1b study, ARQ-234-131, to assess the safety and tolerability of ARQ-234, an investigational biologic for atopic dermatitis.
The double-blind, randomized, placebo-controlled study will evaluate ARQ-234, administered as a subcutaneous injection, in sequential cohorts of healthy volunteers and adults with moderate to severe atopic dermatitis. The study includes single-ascending-dose cohorts, followed by multiple-ascending-dose cohorts and a small proof-of-concept cohort in adults with atopic dermatitis.
ARQ-234 is a fusion protein designed to selectively activate the CD200 receptor (CD200R), an immune-regulatory checkpoint that helps regulate immune responses. By binding to CD200R, ARQ-234 aims to reduce overactive immune responses and restore immune balance.
Dr. Patrick Burnett, chief medical officer at Arcutis, stated that ARQ-234 and its CD200R immune-checkpoint agonist mechanism is a promising pathway to address unmet needs in treating moderate to severe atopic dermatitis.
The Phase 1a/1b study will enroll approximately 125 participants aged 18 to 65 years, including healthy volunteers and individuals with moderate to severe atopic dermatitis. The study consists of three parts: Part A (Phase 1a, single-ascending dose), Part B (Phase 1b, multiple-ascending dose), and Part C (Phase 1b, proof-of-concept expansion). ARQ-234 will be administered as a subcutaneous injectable solution.
The study’s primary objectives are to evaluate the safety and tolerability of ARQ-234 and clinical improvement in adults with moderate to severe atopic dermatitis. The secondary objective is to evaluate pharmacokinetics across single and multiple-dose levels.
Atopic dermatitis, the most common type of eczema, affects approximately 16.5 million adults in the United States. It is a chronic, relapsing, and genetically predisposed inflammatory skin disease characterized by a red, intensely itchy rash.
Checkpoint agonism is an emerging immunomodulatory approach to amplify pathways that inhibit overactive immune cells and suppress unwanted immune responses. Preclinical comparisons of ARQ-234 against a clinically validated CD200R antibody showed favorable data across key metrics including potency, efficacy, and pharmacokinetics, and potential differentiation with a longer half-life and a higher steady-state volume of distribution.
Arcutis Biotherapeutics, Inc. is a commercial-stage medical dermatology company focused on developing innovations for immune-mediated dermatological diseases. The company has a growing portfolio of advanced targeted topicals approved to treat three major inflammatory skin diseases.
Source: Arcutis Biotherapeutics, Inc.
