Real-World Experience of 3-Year Treatment With Dupilumab: Significant Decrease in Circulating Neutrophils and Eosinophils in Japanese Patients With Atopic Dermatitis

Dupilumab, an anti-interleukin (IL)-4 receptor α-antibody, was approved in 2018 for the treatment of moderate-to-severe atopic dermatitis (AD) in Japan. Although real-world data have accumulated on the effectiveness and safety of dupilumab in patients with AD in the short term, real-world data on its long-term use are limited. In this study, we retrospectively investigated its effectiveness, safety and laboratory data in patients with AD who received dupilumab for 3 years. All adult patients with moderate-to-severe AD who were administered dupilumab between June 2018 and December 2020 and were treated with dupilumab for more than 3 years were included in this study. Sixty Japanese patients with AD (male, 48; female, 12) were included in this study. Their mean age was 36.6 ± 11.0 (standard deviation) years. The mean Eczema Area and Severity Index (EASI) was 29.9 ± 9.2. The clinical severity scales, including Investigator's Global Assessment (IGA), EASI and affected body surface area (BSA), and patient-reported outcomes, such as Dermatology Quality Life Index (DLQI), Patient-Oriented Eczema Measure (POEM) and visual analogue scale (VAS) of pruritus, significantly improved at 3 months, and at 1, 2 and 3 years after initiating dupilumab. The total EASI score significantly decreased by a mean of 66.8% at 3 months, 81.0% at 1 year, 85.3% at 2 years and 90.0% at 3 years after initiating dupilumab. The serum levels of thymus and activation-regulated chemokine (TARC), immunoglobulin E (IgE) and lactate dehydrogenase (LDH) significantly decreased at 1, 2 and 3 years. A slight decrease in circulating neutrophils was observed in patients with AD treated with dupilumab over periods from 3 months to 3 years. The number of circulating eosinophils significantly decreased at 2 and 3 years after initiating dupilumab. The most common adverse event was ocular disorders observed in 23 patients (38.3%). Our study shows the sustained effectiveness and tolerable safety of 3-year usage of dupilumab in Japanese patients with atopic dermatitis. Furthermore, dupilumab decreased neutrophil values at 3 months and later, and reduced the number of circulating eosinophils after long-term use (≧ 2 years).