Long-Term Efficacy and Complete Scalp Hair Regrowth in Patients With Alopecia Areata Receiving Ritlecitinib 50 mg QD Up to 3 Years in the ALLEGRO Clinical Trial Program

Abstract

Introduction In clinical trials for alopecia areata (AA), achievement of Severity of Alopecia Tool (SALT) score ≤20 and ≤10 (≤20% and ≤10% scalp hair loss) are commonly reported, but achievement of SALT score 0 (complete scalp hair regrowth), among the most stringent endpoints, is less common. Efficacy results are reported through Month 36-38, including achievement of SALT score 0, in patients with AA receiving ritlecitinib, an oral, selective JAK3/TEC family kinase inhibitor, in the ALLEGRO-2b/3 and ongoing ALLEGRO-LT studies.

Methods Patients aged ≥12 years with AA and ≥50% scalp hair loss who received daily ritlecitinib 50 mg in ALLEGRO-2b/3 (NCT03732807) and continued to receive 50 mg in ALLEGRO-LT (NCT04006457) were included. Data from patients who received placebo and switched to 50 mg were re-baselined to align time points across groups. Observed and last observation carried forward (LOCF) data are reported to June 25, 2024 for SALT score ≤20, SALT score ≤10, and SALT score 0 at Month 36-38; maintenance of SALT score ≤20 response (patients with SALT score ≤20 at Months 12 and 36-38, regardless of SALT score between timepoints); SALT score of 0 at ≥1 time point through Month 36-38; and eyebrow and eyelash assessment (EBA/ELA) response at Month 36-38.

Results 191 patients were included; 14.1% were ongoing at the time of data cutoff. At Month 36-38, 65.1% (71/109 observed) and 47.1% (90/191 LOCF) of patients had SALT score ≤20. Among patients with SALT score ≤20 at Month 12, 88.3% (53/60 observed) and 89.6% (69/77 LOCF) of patients maintained this response at Month 36-38. At Month 36-38, SALT score ≤10 response rates were 52.3% (57/109 observed) and 36.7% (70/191 LOCF); SALT score 0 rates were 31.2% (34/109 observed) and 22.5% (43/191 LOCF).

Most of these patients (61.4%, 35/57) did not have a subsequent increase in SALT score at later visits. Among patients who achieved a SALT score of 0 at ≥1 visit, most (84.2%, 48/57) remained at SALT score ≤5 at subsequent visits.

Of patients with an abnormal EBA/ELA score at baseline, 63.2% (36/57 observed) and 48.7% (75/154 LOCF) had an EBA response at Month 36-38 and 60.4% (32/53 observed) and 49.6% (69/139 LOCF) had an ELA response.

Conclusion Ritlecitinib 50 mg demonstrated clinically meaningful clinician-reported efficacy up to 3 years. Almost one-third of patients achieved complete scalp hair regrowth (SALT score of 0) at ≥1 time point, with the majority sustaining that response at later visits or remaining at SALT score ≤5.