Pediatric Clinical Trial Program in Progress: A Phase 3 Study and Long-term Extension Study to Evaluate the Efficacy and Safety of Ritlecitinib in Children 6 to <12 years of Age With Severe Alopecia Areata

Introduction Ritlecitinib, an oral, selective dual inhibitor of JAK3 and the TEC family kinases, is approved to treat severe alopecia areata (AA) in adults and adolescents aged ≥12 years. There are no treatments approved by the US FDA or the European Medicines Agency for children aged <12 years. A phase 1 study (NCT05650333) characterizing the pharmacokinetics of ritlecitinib in children aged 6 to <12 years with AA demonstrated that ritlecitinib 20 mg was well tolerated. The efficacy and safety of ritlecitinib in children aged 6 to <12 years with severe AA are currently under investigation in an ongoing phase 3 study (NCT07029711) and long-term extension (LTE) study (NCT07029828). The phase 3 study is a randomized, double-blind, placebo-controlled trial evaluating the efficacy, safety, and tolerability of ritlecitinib vs placebo for 24 weeks in children with ≥50% scalp hair loss due to AA. Children who complete the phase 3 study or have completed the phase 1 study may enroll in the double-blind LTE study, which seeks to assess the long-term safety and efficacy of ritlecitinib up to 36 months. Materials & Methods Patients will be age 6 to <12 years with diagnosed AA, ≥50% scalp hair loss (Severity of Alopecia Tool [SALT] score ≥50), and current AA episode duration of ≥12 months. In the phase 3 study, EU/UK patients must have a history of clinical response failure to AA treatment. For the phase 3 study, ~225 patients will be enrolled and randomized 1:1:1 to ritlecitinib 50 mg once-daily (QD), ritlecitinib 30 mg QD, or placebo. The primary efficacy endpoint is response based on SALT score ≤20 at Week 24 for countries following the US analysis plan or SALT ≤10 at Week 24 for countries following the EU/UK analysis plan. The key secondary endpoint for countries following the EU/UK analysis plan is a Patient Global Impression of Change response of “moderately improved” or “greatly improved” at Week 24. For the LTE study, it is estimated that ~140 patients completing the phase 1 or phase 3 studies will be enrolled. Patients who receive ritlecitinib 50 mg QD or 30 mg QD in the phase 3 study will continue receiving the same dose; patients who receive placebo in the phase 3 study and all patients from the phase 1 study will be randomized 1:1 to ritlecitinib 50 mg QD or 30 mg QD. The primary endpoints are incidence of treatment emergent adverse events (AEs), serious AEs (SAEs), and AEs leading to permanent discontinuation. Secondary endpoints include efficacy endpoints and psychological/psychosocial status and neuropsychological/cognitive development status.