Long-Term Efficacy of Ritlecitinib up to Month 24 From the ALLEGRO Phase 2b/3 and Long-Term Phase 3 Clinical Studies in Alopecia Areata

Introduction: Ritlecitinib demonstrated efficacy and safety to Week 48 in patients aged ≥12 years with alopecia areata (AA) in ALLEGRO-2b/3 (NCT03732807). ALLEGRO-LT (NCT04006457) is an ongoing, phase 3, open-label study investigating the long-term safety and efficacy of ritlecitinib in AA. We report updated interim efficacy results of ritlecitinib up to Month 24 from ALLEGRO-2b/3 and ALLEGRO-LT. Methods: Patients aged ≥12 years with AA and ≥50% scalp hair loss who rolled-over to ALLEGRO-LT from ALLEGRO-2b/3 were included. Data are reported for patients who received: 1) daily ritlecitinib 50-mg with a 4-week 200-mg daily loading dose (“200/50-mg”); 2) daily ritlecitinib 50-mg with no loading dose (“50-mg”). Outcomes include the proportions of patients with response (based on Severity of Alopecia Tool [SALT] score ≤20, SALT ≤10, and Patients’ Global Impression of Change [PGI-C] score of “moderately improved” or “greatly improved”) through Month 24, and the proportions of patients sustaining SALT ≤20 response from Month 12 through Month 24. Observed and imputed (modified last observation carried forward [mLOCF]) data, to account for missing values, are reported (data cutoff: December 9, 2022). Results: The 200/50-mg and 50-mg groups included 194 and 191 patients; 127 (65.5%) and 111 (58.1%) were ongoing at the data cutoff. SALT ≤20 response rates in the 200/50-mg and 50-mg groups increased from Month 12 (45.9% and 45.1% [observed]; 41.8% and 40.3% [mLOCF]) to Month 24 (63.1% and 60.8% [observed]; 50.8% and 46.1% [mLOCF]). SALT ≤10 response rates increased between Months 12 and 24 for the 200/50-mg group (39.4% to 51.1% [observed]; 35.6% to 40.9% [mLOCF]) and 50-mg group (34.2% to 50.8% [observed]; 30.9% to 37.7% [mLOCF]). Of SALT ≤20 responders at Month 12, 92.8% (200/50-mg) and 79.7% (50-mg) (observed) sustained this response through Month 24. PGI-C response rates were maintained from Month 12 (200/50-mg: 69.4% [observed], 65.3% [mLOCF]; 50-mg: 61.6% [observed], 57.7% [mLOCF]) to Month 24 (200/50-mg: 76.4% [observed], 65.4% [mLOCF]; 50-mg: 70.0% [observed], 56.6% [mLOCF]). Conclusion: Ritlecitinib 50-mg (with or without a 200-mg loading dose) demonstrated clinically meaningful and sustained clinician- and patient-reported efficacy through Month 24, which supports its long-term use in patients aged ≥12 years with severe AA.