Safety, efficacy, and pharmacokinetics of delgocitinib ointment in infants with atopic dermatitis: A phase 3, open-label, and long-term study.

BACKGROUND: Delgocitinib ointment, a topical Janus kinase inhibitor, is used as treatment of patients with atopic dermatitis (AD) aged ≥2 years in Japan. Although initiating appropriate and early treatment upon the onset of AD in childhood is important, the safety and efficacy of delgocitinib ointment in infants with AD have not been established. METHODS: This phase 3 study was conducted from October 2020 to June 2022 (number JapicCTI-205412). Eligible Japanese infants with AD aged 6 to <24 months received 0.25% or 0.5% of delgocitinib ointment twice daily for 52 weeks in an open-label uncontrolled manner. Topical corticosteroids were allowed to apply for worsening AD during the treatment period at the investigators' discretion. RESULTS: A total of 22 infants were enrolled. Adverse events (AEs) were reported in 21 (95.5%) infants and were mostly mild. No treatment-related AEs were reported. The Modified Eczema Area and Severity Index (mEASI) score continuously decreased until week 4, and the score reduction was maintained until week 52. The mean percent changes in the mEASI score from baseline were -73.5% at week 4, -81.7% at week 28, and -81.9% at week 52. Delgocitinib was not detected in the plasma of most infants (68.2%-95.2%). CONCLUSIONS: Delgocitinib ointment is well tolerated and effective for up to 52 weeks when applied to Japanese infants with AD.