025 Immunological changes in atopic dermatitis patients treated with different dosing intervals of dupilumab

Dupilumab, a fully human IgG4 monoclonal antibody targeting the interleukin-4 receptor alpha (IL4Rα), substantially improves disease severity in patients with atopic dermatitis (AD). While recent daily practice studies have shown that dose reduction of dupilumab is possible controlled AD, associated biological effects are currently unknown. Therefore, we studied levels serum and on IL4Rα occupancy, T-cell functions cytokine production within skin-homing (total CLA+ CLA+/CCR4+) subpopulations AD who were treated 300mg subcutaneously every 2 weeks (Q2W), 4 (Q4W) 6 (Q6W). As time between injections increased, amount bound (anti-IgG4) decreased. During treatment Q2W Q4W, was completely occupied regardless number days injection blood draw. Simultaneously, Eczema Area Severity Index (EASI) score remained stably low IgE declined. Q6W, however, became available again percentage proliferating (Ki67+) Th2 producing CD4+ T-cells increased compared to Q4W. This also reflected clinical parameters slightly rising EASI score. In summary, Q4W inhibited similar immunological effects. The tipping point for seems occur at transition from Q6W.