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Clinical Trial
. 2025 Jul-Aug;42(4):742-746.
doi: 10.1111/pde.15895. Epub 2025 Feb 9.

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

Mercedes E Gonzalez  1 , John Browning  2 , Stacy Smith  3 , Anna Plotka  4 , Jing Daisy Zhu  4 , Shyam Parvatini  5 , Yeamin Huh  6 , Robert Wolk  6
Affiliations
Clinical Trial

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

Mercedes E Gonzalez et al. Pediatr Dermatol. 2025 Jul-Aug.

Abstract

Background: Alopecia areata (AA) is an autoimmune disease characterized by hair loss that can negatively impact quality of life. AA has a significant pediatric prevalence; however, no systemic treatments are approved for AA in patients aged < 12 years. Ritlecitinib, a JAK3/TEC family kinase inhibitor, is approved to treat adults and adolescents with severe AA aged ≥ 12 years. This study evaluated ritlecitinib pharmacokinetic (PK) parameters and safety in pediatric patients with AA aged 6 to < 12 years.

Methods: In this single-group, uncontrolled, open-label study, participants received ritlecitinib 20 mg once daily for 7 days. PK parameters of ritlecitinib on Day 7 were measured and summarized descriptively. Safety outcomes, including incidence of adverse events (AEs), were evaluated.

Results: Fifteen participants were enrolled and 14 (93.3%) completed the study. The median time to maximum concentration (Tmax) for plasma concentrations of ritlecitinib on Day 7 was ~0.5 h. The mean half-life of ritlecitinib was ~1.19 h. Geometric means (% coefficient of variation) for area under the curve from 0 to 24 h (AUC24) and maximum concentration (Cmax) were 437.5 ng·h/mL (30%) and 208.7 ng/mL (38%), respectively. Four AEs were experienced by 3 participants, with 1 AE of urticaria resulting in permanent discontinuation. No severe AEs, serious AEs, or clinically meaningful laboratory abnormalities were reported.

Conclusions: Ritlecitinib PK parameters in pediatric patients were successfully characterized in the present study. Ritlecitinib 20 mg once daily was generally well tolerated in pediatric patients with AA.

Trial registration: NCT05650333.

Keywords: alopecia areata; children; clinical trial; pediatrics; pharmacokinetics.

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Conflict of interest statement

M.E.G. declares being an investigator for AbbVie, Arcutis Biotherapeutics, Amgen, Anterogen, Dermavant, Eli Lilly, Incyte, Krystal Biotech, Neilsen Biosciences, Novartis, Pfizer, Regeneron, and Sanofi; being a consultant for Abeona Therapeutics, Arcutis Biotherapeutics, Alphyn Biologics, Dermavant, Eli Lilly, Incyte, Krystal Biotech, and Verrica Pharmaceuticals; and being on speakers bureaus for AbbVie, Arcutis, Eli Lilly, Krystal Biotech, Pfizer, Regeneron, Sanofi, and Verrica Pharmaceuticals. J.B. declares no conflicts. S.S. has received research grants from Teoxane SA. At the time of the study, A.P., J.Z., S.P., Y.H., and R.W. were employees of and may own shares/stock options in Pfizer.

Figures

FIGURE 1
FIGURE 1
Study design.
FIGURE 2
FIGURE 2
(A) Linear median plasma ritlecitinib concentration‐time curve (ng/mL) and (B) Semi‐log median plasma ritlecitinib concentration‐time curve (ng/mL). QD, once daily.
See this image and copyright information in PMC

References

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