Efficacy of Ritlecitinib in Patients with Alopecia Areata by Extent of Hair Loss: Results from the Phase 2b/3 and Phase 3 ALLEGRO Clinical Trials

Abstract

Introduction: Ritlecitinib, a dual JAK3/TEC family kinase inhibitor, demonstrated efficacy and safety in patients ≥12 years old with AA and ≥50% scalp hair loss in the phase 2b/3 ALLEGRO study. This post hoc, pooled analysis of the ALLEGRO-2b/3 and phase 3 ALLEGRO-LT studies evaluated the efficacy of ritlecitinib in patients with alopecia areata (AA) by extent of baseline scalp hair loss through Month 24. Methods: Patients aged ≥12 years with AA and ≥50% scalp hair loss who received ritlecitinib 50 mg daily in ALLEGRO-2b/3 and rolled over to ALLEGRO-LT (continued to receive 50 mg) were included. Outcomes included the proportions of patients achieving response based on Severity of Alopecia Tool [SALT] score ≤20 (≤20% scalp hair loss), ≥2-grade improvement in eyebrow assessment [EBA] score (among patients with abnormal score at baseline), and ≥2-grade improvement in eyelash assessment [ELA] score (among patients with abnormal score at baseline). Patients were stratified by extent of scalp hair loss at baseline, defined as severe AA (SALT score 50-94) or very severe AA (SALT score 95-100), as per the Alopecia Areata Investigator Global Assessment (AA-IGA). Data as observed and imputed (last observation carried forward [LOCF]) are reported at the cutoff date (December 9, 2022). Results: Of 191 patients included, 66 (34.6%) had severe AA and 125 (65.4%) had very severe AA at baseline. At Month 12, 64.4% and 34.3% (observed) and 60.6% and 29.6% (LOCF) of patients with severe AA and very severe AA, respectively, achieved SALT ≤20. At Month 24, these proportions increased to 70.2% and 54.8% (observed) and 63.6% and 36.8% (LOCF), respectively. EBA response was achieved in 54.6% and 46.9% (observed) and 52.8% and 42.4% (LOCF) of patients with severe AA and very severe AA, respectively, at Month 12; at Month 24, the proportions were 60.9% and 56.5% (observed) and 50.0% and 45.8% (LOCF). ELA response was achieved in 60.7% and 40.5% (observed) and 61.3% and 38.0% (LOCF) of patients with severe AA and very severe AA, respectively, at Month 12; at Month 24, the proportions were 70.0% and 45.3% (observed) and 61.3% and 38.0% (LOCF). Conclusion: Ritlecitinib 50 mg daily achieves scalp, eyebrow, and eyelash hair regrowth in patients with severe and very severe AA. Funding: This study was funded by Pfizer Inc