Safety and efficacy of delgocitinib ointment in adult patients with atopic dermatitis based on disease severity:

Objective: This study investigated the safety and efficacy of delgocitinib ointment (0.5%), a novel Janus kinase (JAK) inhibitor, in 352 adult Japanese patients with atopic dermatitis (AD) based on disease severity. Methods: Results of a Japanese phase III multicenter, uncontrolled, open-labeled, long-term, 52-week study in adult patients with mild to severe AD were analyzed post hoc. Then, the safety and efficacy of the delgocitinib ointment were assessed using a 50% and 75% reduction in the cumulative modified eczema area and severity index (cumulative mEASI50/75) based on disease severity, as measured using the investigator’s global assessment (IGA) score at the start of treatment, and on concomitant use of topical corticosteroids (TCS). Results: Patients who experienced adverse drug reactions were 23/110 patients (20.9%), 45/215 patients (20.9%), and 1/27 patients (3.7%) with IGA 2 (mild), IGA 3 (moderate), and IGA 4 (severe), respectively, at the start of treatment. Moreover, the total number of patients with adverse drug reactions with and without the TCS treatment was 43/224 patients (19.2%) and 25/128 patients (19.5%), respectively. In the population using delgocitinib ointment alone (128 patients), the percentage of patients achieving cumulative mEASI50 and mEASI75 was 87.0% and 69.6%, 72.2% and 62.5%, and 85.7% and 14.3% in the IGA 2, IGA 3, and IGA 4 subpopulations, respectively. However, in the overall population, the percentage of patients achieving cumulative mEASI50 and mEASI75 was 78.8% and 54.8%, 62.8% and 43.7%, and 74.0% and 37.0% in the IGA 2, IGA 3, and IGA 4 subpopulations, respectively. Conclusion: Since no significant difference in adverse drug reactions was observed at any IGA level of AD and the efficacy was demonstrated through improved skin rash during AD, the delgocitinib ointment is considered safe regardless of disease severity. It is essential not only to control AD with delgocitinib ointment alone, but also to consider the use of TCS in combination as appropriate for the disease severity and symptoms.