Stratum Corneum Hydration As a Potential Marker of Response to Dupilumab in Atopic Dermatitis®: A Prospective Observational Study.

Background: Dupilumab is an effective treatment for atopic Dermatitis® (AD) and it also restores skin barrier function. Nevertheless, early changes in epidermal barrier parameters related to sustained treatment response or treatment failure are not known. So, the objective of this study is to evaluate whether changes in skin barrier function after 16 weeks dupilumab treatment could predict sustained treatment response or treatment failure. Materials and Methods: A prospective observational study was conducted that included patients with AD starting dupilumab. Clinical scores, patient-reported outcome measures (PROMs), and skin barrier function parameters were assessed at baseline and after 16 weeks treatment. Patients were followed until they failed to dupilumab or until the end of the study period. Participants were divided into 2 groups: patients with treatment failure and those with sustained treatment response. Results: In total, 32 patients with AD were included in the study, with a mean age of 28.03 years (standard deviation 10.65), being 20 (60.6%) females. In total, 22 (66.7%) patients sustained dupilumab response during the study period and only 10 (33.3%) failed to treatment. After 16 weeks treatment, clinical scores were improved in both groups. Patients with sustained treatment response increased stratum corneum hydration (SCH) on noninvolved skin (34.25 arbitrary units [AU] vs 44.90AU, P = 0.001) and on eczematous lesions (20.71 AU vs 40.94 AU, P < 0.001) and also decreased transepidermal water loss (TEWL) on eczematous lesions (28.22 g/[m²·h] vs 14.83 g/[m²·h], P = 0.002). Patients with treatment failure did not change TEWL or SCH. SCH after 16 weeks treatment on noninvolved skin (odds ratio [OR] = 0.83, P = 0.018) and SCH after 16 weeks treatment on eczematous lesions (OR = 0.86, P = 0.028) were related to dupilumab failure. Conclusion: SCH could be used as a predictive biomarker of dupilumab response in patients with AD.