Delgocitinib ointment, a topical Janus kinase inhibitor, in adult patients with moderate to severe atopic dermatitis: A phase 3, randomized, double-blind, vehicle-controlled study and an open-label, long-term extension study

Background: Previous studies showed the potential effectiveness of delgocitinib ointment, a novel topical Janus kinase inhibitor, in atopic dermatitis (AD). Objective: This study aimed to evaluate the efficacy and safety of delgocitinib 0.5% ointment. Methods: In part 1, a 4-week double-blind period, Japanese patients aged 16 years or older with moderate or severe AD were randomly assigned in a 2:1 ratio to delgocitinib 0.5% ointment or vehicle ointment. Eligible patients entered part 2, a 24-week extension period, to receive delgocitinib 0.5% ointment. Results: At the end of treatment in part 1, the least-squares mean percent changes from baseline in the modified Eczema Area and Severity Index score, the primary efficacy endpoint, were significantly greater in the delgocitinib group than in the vehicle group (-44.3% vs 1.7%, P < .001). The improvement in modified Eczema Area and Severity Index score was maintained in part 2. Most adverse events were mild and unrelated to delgocitinib across the study periods. Limitations: Only Japanese patients were included. The vehicle-controlled period lasted only 4 weeks. In part 2, topical corticosteroids were allowed for the treatment of worsening of AD. Conclusion: Delgocitinib ointment was effective and well tolerated in Japanese adult patients with moderate to severe AD for up to 28 weeks.