A Phase 1, Open-Label Study of the Pharmacokinetics of Ritlecitinib in Children Aged 6–12 Years With Alopecia Areata

This study investigated the pharmacokinetics and safety of ritlecitinib, a JAK3/TEC family kinase inhibitor, in children aged 6 to < 12 years with alopecia areata (AA). Conducted as a single-group, open-label study, participants received 20 mg of ritlecitinib daily for 7 days. The pharmacokinetic parameters were successfully characterized, with results showing a mean area under the curve (AUC) of 437.5 ng·h/mL and a maximum concentration (Cmax) of 208.7 ng/mL. Safety evaluation revealed four adverse events in three participants, including one case of urticaria leading to discontinuation, but no severe or serious adverse events were reported. Overall, ritlecitinib was generally well tolerated in this pediatric population.