Efficacy Outcomes in Clinical Trials of Atopic Dermatitis Treatments: A Systematic Literature Review

Abstract

Introduction: Complete skin clearance is a key atopic dermatitis (AD) treatment goal. Treatment efficacy in AD trials is evaluated using a range of clinical measures with the Investigator’s Global Assessment (IGA) as a key endpoint. Multiple and varied forms of the IGA scale are utilized across trials, including the Investigator’s Static Global Assessment and the Validated Investigator Global Assessment for AD^TM. IGA scores usually range from 0 (clear) to 1 (almost clear), 2 (mild), 3 (moderate), and 4 (severe), but contain differences in detail assessed. Efficacy endpoints using IGA scales include achieving IGA=0 or 1 with ≥2-point improvement from baseline, or IGA=0. The Eczema Area and Severity Index (EASI) and achievement of ≥75% or ≥90% improvement from baseline (EASI75 and EASI90) are additional gold-standard measurements.

Objective: To compare differences in efficacy outcomes in recent clinical trials of FDA-approved AD treatments for adults and children.

Methods: A systematic literature search was conducted using MEDLINE, Embase, Cochrane Library, and hand search to identify AD trials published in English language between January 1, 2016 and August 16, 2023. Trials could include patients with any severity of AD who were treated with topical therapies (crisaborole, ruxolitinib), injectable systemics (dupilumab, tralokinumab), or oral systemics (upadacitinib, abrocitinib) according to approved indications. Efficacy outcomes of IGA=0 or 1 with ≥2-point improvement, IGA=0, EASI75, and EASI90 were categorized and summarized by AD severity, treatment type, and age groups in the trials.

Results: Of 50 publications identified, 40 (80%) reported randomized controlled trials, 2 (4%) single-arm trials, and 8 (16%) open-label extension trials. By patient age groups, 11 publications were on children (<12 years), 8 on adolescents (12–17 years),15 on patients ≥12 years, and 17 on adults (≥18 years). Moderate to severe AD was the most frequently studied severity (38/50 publications), of which all trials were either as systemic monotherapy or systemic therapy combined with a topical. Topical monotherapy for mild to moderate AD only was reported in 8/50 publications. For topicals, achievement of IGA=0 (clear) was not reported for any age group, and no trials reported EASI90 for children <12 years. For injectable systemics, no outcome was reported for IGA=0 (clear) in children <12 years. For oral systemics, no outcomes were reported for children <12 years.

Conclusions: This literature search of AD trial publications on FDA-approved treatments from 2016 onwards revealed several gaps in available outcomes data. There were no trials that assessed a topical therapy for moderate to severe AD, and complete disease clearance (IGA=0) was not demonstrated for any topicals. The findings reinforce the unmet need for a topical AD treatment that can provide high efficacy including complete clearance without restriction based on age or disease severity.

Funding Support: Dermavant Sciences, Inc.