Efficacy and safety of the oral Janus kinase 3/tyrosine kinase expressed in hepatocellular carcinoma family kinase inhibitor ritlecitinib over 24 months: integrated analysis of the ALLEGRO phase IIb/III and long-term phase III clinical studies in alopecia areata.

BACKGROUND

The ALLEGRO phase IIa and IIb/III (NCT02974868 and NCT03732807) studies have demonstrated that ritlecitinib is effective and well tolerated in adults and adolescents with alopecia areata (AA) up to 48 weeks.

OBJECTIVES

To assess the efficacy of ritlecitinib through month 24 and safety through data cutoff in the ALLEGRO phase IIb/III study and the ongoing long-term open-label phase III ALLEGRO-LT study (NCT04006457).

METHODS

Patients aged ≥ 12 years with AA and ≥ 50% scalp hair loss from ALLEGRO IIb/III who rolled over to ALLEGRO-LT after up to 48 weeks were included. Proportions of patients with responses based on clinician-reported Severity of Alopecia Tool (SALT) scores of ≤ 20 and ≤ 10, eyebrow assessment (EBA) and eyelash assessment (ELA), patient global impression of change (PGI-C) and patient satisfaction with hair growth were reported through month 24 for patients who received ritlecitinib 50 mg daily with or without a 200-mg 4-week daily loading dose. Observed and imputed data [last observation carried forward (LOCF)] were reported up to 9 December 2022. Safety was assessed throughout.

RESULTS

At month 12, a SALT score ≤ 20 was achieved by 45.1% and 45.9% (observed) and 40.3% and 41.8% (LOCF) of the 191 and 194 patients who received ritlecitinib 50 mg and ritlecitinib 200 mg/50 mg, respectively. At month 24, these proportions increased to 60.8% and 63.1% (observed) and 46.1% and 50.8% (LOCF), respectively. Patients with abnormal EBA or ELA scores at baseline achieved responses at month 24 [EBA observed: 57.6% (50 mg), 61.0% (200/50 mg); EBA LOCF: 46.8% (50 mg), 50.9% (200/50 mg); ELA observed: 51.2% (50 mg), 62.7% (200/50 mg); ELA LOCF: 43.2% (50 mg), 51.7% (200/50 mg)]. PGI-C response was achieved by patients at month 24 [observed: 70.0% (50 mg), 76.4% (200/50 mg); LOCF: 56.6% (50 mg), 65.5% (200/50 mg)]. Safety profiles for both treatment groups were consistent with the known safety profile of ritlecitinib.

CONCLUSIONS

Ritlecitinib has clinically meaningful and sustained efficacy beyond 1 year with a favourable safety and tolerability profile, supporting its long-term use in patients aged ≥ 12 years with AA.