Scalp, eyebrow, and eyelash hair regrowth with continued ritlecitinib treatment among patients with alopecia areata without target efficacy response at Week 24: post hoc analysis of the ALLEGRO phase 2b/3 study

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Maryanna Senna
Seth Forman
Lindsey Bordone
Pablo De La Cueva Dobao
Robert Wolk
Samuel Zwillich
Fan Zhang
Haytham Mohamed Ahmed
Liza Takiya


alopecia areata, Ritlecitinib, JAK inhibitor


Background: This post hoc analysis of the ALLEGRO phase 2b/3 study (NCT03732807) assessed response to ritlecitinib, an oral JAK3/TEC family kinase inhibitor, between Weeks 28-48 among patients with alopecia areata (AA) who did not meet target efficacy response criteria at Week 24.

Methods: Patients aged ≥12 years with AA and ≥50% scalp hair loss received daily ritlecitinib 10 mg (included for dose ranging only), 30 or 50 mg (±4-week 200-mg daily loading dose), or placebo for 24 weeks. After Week 24, ritlecitinib groups continued their assigned doses and the placebo group switched to ritlecitinib 200/50 or 50 mg through Week 48. This analysis included patients receiving ritlecitinib 30 or 50 mg (±4-week 200-mg daily loading dose) who had not responded at Week 24, based on Severity of Alopecia Tool (SALT) score ≤20 (≤20% scalp without hair), SALT score ≤10, or eyebrow (EBA) or eyelash (ELA) assessment (normal or ≥2-grade improvement from baseline among patients with abnormal EBA or ELA score at baseline), and followed them through Week 48.

Results: Of the patients in the ritlecitinib groups who did not meet SALT ≤20 response at Week 24, 5-8% had response at Week 28, with rates increasing to 22-34% at Week 48. A similar trend was observed for SALT ≤10 (6-12% and 20-25%), EBA (8-14% and 20-33%), and ELA (4-15% and 17-30%) at Weeks 28 and 48, respectively, for patients not achieving the respective response at Week 24. Ritlecitinib was well tolerated through Week 48. Most common adverse events were upper respiratory tract infection, nasopharyngitis, and headache.

Conclusion: Patients with AA treated with ritlecitinib who don’t meet target efficacy response at Week 24 may achieve response at later time points with continued ritlecitinib treatment.


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2. King B, et al. Lancet 2023;401:1518-1529.

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