Nemolizumab demonstrated a consistent long-term safety profile through week 152 in the ARCADIA LTE trial.The open-label long-term extension (LTE) of the ARCADIA trial demonstrates the safety and efficacy of nemolizumab for up to 152 weeks in adults and adolescents with moderate-to-severe atopic dermatitis (AD).
“Nemolizumab treatment was effective through week 152 and well tolerated with a low study discontinuation rate due to adverse events (AEs),” noted Dr Matthias Augustin from the Institute for Health Services Research in Dermatology and Nursing, University Medical Center Hamburg in Germany, at EADV 2026.
“Sustained and continuous improvements were observed in skin lesions, itch relief, sleep disturbance, and quality of life (QoL),” Augustin added.
The LTE study enrolled 1,901 participants (1,164 nemolizumab-previously experienced [NPE] and 737 nemolizumab-naïve [NN]) from the phase III ARCADIA 1 and 2 trials and other nemolizumab studies. Of these, 52 percent had completed week 152 at data cutoff. The participants received subcutaneous nemolizumab 30 mg Q4W alongside background topical corticosteroids (low/medium potency) with or without topical calcineurin inhibitors. [EADV 2026, abstract 3465]
The mean age was 34.4 years in the NPE group and 33.3 years in the NN group. Fifty-one percent of the participants were men, and approximately 12 percent were Asian.
Safety profile
Overall, the rates of any serious treatment-emergent adverse event (TEAE), serious TEAE related to the study drug, and severe TEAE were low (9.4, 1, and 8.7 percent, respectively). Five percent permanently discontinued the study due to TEAEs.
The most frequently reported AEs were nasopharyngitis, COVID-19, and AD (21.1, 20.2, and 19.5 percent, respectively). Exposure-adjusted incidence rates for any TEAEs were 107.5/100 person years (PY) and 194.3/100 PY in the respective NPE and NN subgroups.
Efficacy, QoL
In the observed cases (OC) analysis, approximately two-thirds (64.7 percent) of participants in the NPE group achieved IGA* 0/1 at week 152. EASI-50/75/90** rates were 97, 88.2, and 71.7 percent, respectively.
The proportions of NPE participants who achieved a ≥4-point improvement from lead-in baseline in SCORAD*** VAS# Pruritus and Sleep Loss were 88.4 percent and 70.5 percent, respectively. Of note, 73.1 percent achieved a SCORAD VAS Pruritus score <2, which corresponds to an itch-free/nearly itch-free state.
The multiple imputation–missing-at-random (MI-MAR) analysis of the NPE cohort reinforced the results of the OC analysis (IGA 0/1: 57 percent; EASI-50/75/90: 74.2, 61.4, and 46.1 percent, respectively).
Ninety-two percent of adult participants in the NPE group achieved a ≥4-point improvement from lead-in baseline in Dermatology Life Quality Index (DLQI), and 57.3 percent achieved a DLQI score of 0/1. A similar pattern was observed among adolescents (91.2 percent and 58.6 percent, respectively).
The results in the NN subgroup mirrored that reported for the NPE subgroup across all endpoints in both OC and MI–MAR analyses.
Takeaways
The study showed that nemolizumab demonstrated a consistent long-term safety profile through week 152, with no new safety signals identified.
“The OC analysis demonstrated sustained efficacy with high levels of skin clearance, durable itch relief and sleep improvements, with most patients achieving an itch-free or nearly itch-free state, and clinically meaningful QoL improvements,” Augustin said.
The convergence of treatment responses between NPE and NN patients support the consistent long-term benefit of nemolizumab, he continued.
“The MI-MAR analysis confirmed the robustness of the findings from the OC analysis, showing consistency in treatment effect up to week 152,” Augustin added.