Dupilumab in Adults With Moderate to Severe Atopic Dermatitis: A 5-Year Open-Label Extension Study.

Importance: Moderate to severe atopic dermatitis (AD) is a chronic inflammatory skin disease that often requires continuous long-term systemic management. Long-term safety and efficacy data for treatment options are critically important.

Objective: To assess the safety and efficacy of dupilumab treatment for up to 5 years in adults with moderate to severe AD.

Design, setting, and participants: The 5-year LIBERTY AD open-label extension study was conducted from September 2013 to June 2022 at 550 sites in 28 countries. The study enrolled adult patients with moderate to severe AD who had participated in previous dupilumab clinical trials. Data were analyzed from August 2022 to February 2023.

Exposures: At enrollment, patients initiated a regimen of subcutaneous dupilumab, 200 mg, weekly (400-mg loading dose). The regimen was amended in June 2014 to dupilumab, 300 mg, weekly (600-mg loading dose) based on a dose-ranging study and again in November 2019 to dupilumab, 300 mg, every 2 weeks to align with the regulatory regimen approvals.

Main outcomes and measures: The primary end points were the incidence and rate of treatment-emergent adverse events (TEAEs). Key secondary end points included incidence and rate of serious TEAEs and adverse events of special interest, proportion of patients achieving an Investigator's Global Assessment (IGA) score of 0 or 1 (clear or almost clear), and proportion of patients with 75% or more improvement in the Eczema Area and Severity Index (EASI) from the parent study baseline.

Results: A total of 2677 patients were enrolled and treated in the open-label extension study; 1611 (60.2%) were male, and the mean (SD) age was 39.2 (13.4) years. A total of 334 patients (12.5%) completed treatment up to week 260. The most common reasons for withdrawal were due to regulatory approval of dupilumab in compliance with the study protocol (810 of 1380 [58.7%]), patient withdrawal (248 of 1380 [18.0%]), and adverse events (116 of 1380 [8.4%]). Exposure-adjusted rates of TEAEs were generally stable or declined throughout the study. Common TEAEs (incidence of 5% or greater) included nasopharyngitis, worsening AD, upper respiratory tract infection, conjunctivitis, conjunctivitis allergic, headache, oral herpes, and injection-site reaction. At week 260, 220 of 326 patients (67.5%) achieved an IGA score of 0 or 1 and 288 of 324 (88.9%) achieved 75% or greater improvement in the EASI. The mean (SD) EASI score was 16.39 (14.60) at baseline and 2.75 (5.62) at end of study.

Conclusions and relevance: In this study, there was sustained safety and efficacy of continuous long-term dupilumab treatment for adults with moderate to severe AD.