Safety and efficacy of nemolizumab for atopic dermatitis up to 2 years in open-label extension study

Background: Atopic dermatitis (AD) is a common, chronic, relapsing, pruritic, neuroimmune skin disease, requiring long-term symptom control. Objectives: The ARCADIA long-term extension (LTE) study evaluates nemolizumab safety and efficacy in ≥12-year-old patients with moderate-to-severe AD up to 200 weeks. Methods: Patients from previous nemolizumab AD trials (Phase 2/3) or newly recruited adolescents with moderate-to-severe AD were enrolled. A background regimen of topical corticosteroids with/without topical calcineurin inhibitors was permitted based on disease control. Long-term safety was the primary endpoint. Efficacy assessments were secondary endpoints, including the proportion of patients achieving Investigator's Global Assessment (IGA) 0/1 (clear/almost clear), Eczema Area and Severity Index (EASI)-75 (75% improvement from lead-in baseline in EASI), Visual Analogue Scale (VAS) Pruritus and VAS sleep loss ≥4-point improvement from lead-in baseline and quality of life. Observed data up to Week (W) 104 are presented for patients with previous nemolizumab experience (PNE) and no previous nemolizumab experience (NNE) at LTE baseline. Results: At interim analysis data cut-off (21 July 2024), 1062 of 1901 patients completed W104. Exposure to nemolizumab in this study was equal across cohorts. The majority (92.6%) of treatment-emergent adverse events (TEAEs) were mild/moderate in severity; only 22.1% were considered related to nemolizumab. The most common (≥5.0%) TEAEs were COVID-19 (19.6%), nasopharyngitis (19.5%), atopic dermatitis (18.1%), upper respiratory tract infection (12.7%), headache (6.5%) and asthma (5.5%). At LTE baseline, the proportion of PNE and NNE patients was IGA 0/1: 27.1% and 17.1%; EASI-75: 38.8% and 25.8%; VAS Pruritus ≥4-point improvement: 58.7% and 31.6%; and VAS sleep loss ≥4-point improvement: 52.9% and 31.6%, respectively. At W104, this proportion was IGA 0/1: 62.6% and 58.2%; EASI-75: 88.2% and 85.4%; VAS Pruritus ≥4-point improvement: 87.2% and 82.0%; and VAS sleep loss ≥4-point improvement: 70.8% and 68.9%, respectively. Conclusions: Continuous nemolizumab treatment was well-tolerated through W104 with clinically meaningful improvements in AD signs and symptoms and patient-reported outcomes. Trial Registration: NCT03989206: https://clinicaltrials.gov/search?term=NCT03989206; EUDRACT number: 2019–001889-15. Data available upon request: [email protected].