Bimekizumab as an Effective Treatment in Darier Disease: Clinical Outcomes of a Single-Center Retrospective Analysis of Patients Treated with Biologics.

INTRODUCTION: Darier disease (DD) is a rare autosomal dominant genodermatosis with limited systemic therapeutic options. Retinoids are the gold standard therapy, but long-term application is frequently limited by adverse events. Case reports suggest that biologicals approved for psoriasis vulgaris or atopic dermatitis may be beneficial in DD. METHODS: In this retrospective study, patients with DD who presented to the Department of Dermatology and Venerology, University Hospital Freiburg, between 2019 and 2024 were identified, and clinical efficacy, patient-reported outcomes, and histological features were analyzed in the patients treated with biologic agents in routine care. RESULTS: In total, 15 patients (female: 11, male: 4) with a mean age of 48.20 ± 9.16 years were treated with biologic agents. The three patients who received the type 2 inhibitors dupilumab or lebrikizumab worsened or remained unchanged and discontinued therapy by week 12. Patients treated with the interleukin-17A/F inhibitor bimekizumab showed reduction of the Investigator Global Assessment score and body surface area from a mean of 3.58 ± 0.56 at baseline to 1.80 ± 0.82 at week 24 (p < 0.001) and from 32.00 ± 19.17% to 13.60 ± 9.05% (week 24; p < 0.001), respectively. The Dermatology Life Quality Index score decreased from 18.45 ± 9.87 to 4.78 ± 6.12 (week 24; p < 0.001). Additionally, on histopathology, the total numbers of dyskeratoses showed a trend towards reduction (31.17 ± 10.19 at baseline to 13.67 ± 13.25 at week 12; p = 0.062) with a decrease in the number of grains (10.50 ± 6.77 to 3.33 ± 3.88; p = 0.031). CONCLUSIONS: In summary, these real-world data indicate that bimekizumab may be a beneficial and relatively safe treatment option in DD.