Time of Day of Biological Treatment Administration and Outcomes in Atopic Dermatitis: Results from a Preliminary Retrospective Study.

Growing evidence on chronotherapy supports administering treatments according to endogenous biological rhythms. To evaluate whether the administration time of dupilumab affects its effectiveness in patients with atopic dermatitis (AD), by virtue of the circadian oscillations of immune system activity. This retrospective study included all adult patients with AD treated with dupilumab from January 2020 to January 2024 at our unit. Data recorded at baseline (T0) and at the 16-week-treatment visit (T16) included itch severity, sleep disturbance, Eczema Area and Severity Index, Patient-Oriented Eczema Measure, Dermatology Life Quality Index, and immunoglobulin E levels. Therapeutic response was compared between two groups, based on injection time, that is, between 12:00 a.m. and 12:00 p.m. versus between 12:00 p.m. and 12:00 a.m. Fifty-three patients were included, of whom 21 took dupilumab between 12:00 a.m. and 12:00 p.m. and 32 between 12:00 p.m. and 12:00 a.m. All clinical parameters improved from T0 to T16, without significant differences between groups. However, there was a greater improvement in these parameters in subjects taking dupilumab between 12:00 a.m. and 12:00 p.m., compared with the others. These preliminary results suggest a difference in therapeutic response to dupilumab based on the administration time, leading to potential optimization of its efficacy. Further studies on larger samples are needed.