Efficacy and safety of the oral JAK3/TEC family kinase inhibitor ritlecitinib over 24 months: integrated analysis of the ALLEGRO phase 2b/3 and long-term phase 3 clinical studies in alopecia areata

Br J Dermatol. 2024 Oct 21:ljae365. doi: 10.1093/bjd/ljae365. Online ahead of print.

Abstract

Background: The ALLEGRO phase 2a and 2b/3 studies demonstrated that ritlecitinib is efficacious and well tolerated in adult and adolescent patients with alopecia areata (AA) up to 48 weeks.

Objective: The efficacy of ritlecitinib through Month 24 and safety through data cutoff were assessed in the ALLEGRO phase 2b/3 study and the ongoing long-term, open-label, phase 3 ALLEGRO-LT study.

Methods: Patients aged ≥12 years with AA and ≥50% scalp hair loss from ALLEGRO-2b/3 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) score of ≤20 and ≤10, eyebrow assessment (EBA) and eyelash assessment (ELA), patient global impression of change (PGI-C) and patient satisfaction with hair growth are 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 until December 9, 2022. Safety was assessed throughout.

Results: At Month 12, 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 200/50 mg, respectively. At Month 24, 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.

Conclusion: 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.

Trial registries: ClinicalTrials.gov: NCT03732807, NCT04006457.

Plain language summary

A study to understand the effect of ritlecitinib 50 milligrams once daily in people with alopecia areata treated for up to 2 years Alopecia areata (AA) is a condition where the immune system mistakenly attacks hair follicles, causing hair loss. It affects around 2% of people worldwide, including children and adults. AA may involve small patches or complete loss of hair on the scalp and/or body. People with AA may need to use medicines for a long time to manage hair loss. But there are not many options available. Ritlecitinib is a pill taken by mouth daily to treat severe AA. It blocks the steps that cause hair loss. In the ALLEGRO-LT study, we looked at how well ritlecitinib worked over 2 years in people aged 12 years and older with AA who had lost at least half of their scalp hair. We measured hair loss on the scalp, eyebrows and eyelashes, as well as how satisfied people were with their hair regrowth. We also looked at how safe ritlecitinib was when taken for 2 years. A total of 191 people from 17 countries took ritlecitinib 50 milligrams (the approved dose). After 1 year, 74 out of 164 people (45%) had scalp hair regrowth (20% or less scalp hair loss), increasing to 61% after 2 years. For every 8 out of 10 people, their scalp hair regrowth was maintained from 1 to 2 years. Eyebrow and eyelash hair regrowth also increased over 2 years. Around 8 out of 10 people were satisfied with their hair growth after 2 years, and the safety of ritlecitinib was as expected from the studies done before. The results show that ritlecitinib is effective and appropriate for long-term use in people aged 12 years and older with AA.

Associated data

  • ClinicalTrials.gov/NCT03732807
  • ClinicalTrials.gov/NCT04006457