Three-year data from the ARCADIA open-label extension study show that Nemluvio (nemolizumab) delivered sustained and continuous improvements across skin lesions, itch, sleep disturbance and quality of life in adults and adolescents with moderate-to-severe atopic dermatitis, according to Galderma (SIX: GALD).

The Swiss pure-play dermatology company will present the findings in an oral presentation at the 2026 European Academy of Dermatology and Venereology (EADV) Congress in Vienna, Austria, on Thursday, October 1. The presentation, titled “Long-term safety and efficacy (up to 152 weeks) of nemolizumab in ARCADIA open-label extension study in adults and adolescents with moderate-to-severe atopic dermatitis,” will be delivered by Dr Matthias Augustin, an ARCADIA clinical trial investigator.

The dataset extends to 152 weeks — nearly three years of continuous exposure — making it one of the longer-term readouts for an IL-31 receptor-targeting antibody in the atopic dermatitis population. Galderma reports that the extension study demonstrated a well-tolerated safety profile alongside the durable efficacy signals.

What the ARCADIA data cover

The long-term extension enrolled both adults and adolescents with moderate-to-severe disease, and the endpoints tracked in the presentation span four domains that clinicians weigh heavily in atopic dermatitis management: objective skin lesion improvement, pruritus, sleep disturbance — a direct downstream consequence of chronic itch — and patient-reported quality of life. Sustained improvement across all four domains over 152 weeks addresses a persistent clinical question for biologic therapy in atopic dermatitis: whether early gains hold up over years of treatment or erode over time.

The open-label design of ARCADIA is a relevant caveat when interpreting the findings. Unlike the blinded, placebo-controlled pivotal studies that supported Nemluvio's initial approvals, extension studies lack a comparator arm, which limits causal inference on efficacy durability even as they provide valuable long-term safety exposure data.

Context from Galderma's broader Nemluvio program

The atopic dermatitis extension data are not the only long-term evidence Galderma has generated for nemolizumab. In February 2026, the company reported that Nemluvio provides long-term disease control in prurigo nodularis, the drug's second approved indication. Together, the two datasets position Nemluvio as a treatment with durability evidence across both of its labeled chronic, pruritus-driven conditions.

For dermatologists, the durability question is central. Atopic dermatitis is a lifelong, relapsing disease, and payers and clinicians alike want evidence that biologics maintain efficacy without dose escalation or waning response. A 152-week dataset showing continuous improvement in itch and sleep — the symptoms patients rank as most burdensome — speaks directly to that concern.

Presentation details

The oral presentation is scheduled for the opening day of the EADV Congress, October 1, 2026, in Vienna. Dr Augustin, who served as a clinical trial investigator in the ARCADIA program, will present the long-term safety and efficacy results.

Derm Field will monitor the presentation for full endpoint-level results, including magnitude of change on validated atopic dermatitis instruments and detailed safety event rates, once the data are released at the congress. How the 152-week profile compares with long-term datasets from other atopic dermatitis biologics, and whether the adolescent subgroup shows responses consistent with the adult cohort, will be key questions for the Vienna audience.