Ritlecitinib Effective for Alopecia Areata Patients with ≥25% Hair Loss


These data highlight the efficacy of ritlecitinib for patients with alopecia areata and extensive hair loss at baseline.

Christos Tziotzios

Credit: OneWelbeck

Christos Tziotzios

Credit: OneWelbeck

Ritlecitinib is efficacious among individuals with alopecia areata and reporting ≥25% hair loss, according to recent findings, including such patients who report extensive hair loss at the point of baseline.1

This research was presented at the Revolutionizing Atopic Dermatitis (RAD) 2024 Annual Meeting. The study itself was led by Christos Tziotzios, of St John's institute of dermatology at King's College London in the UK.

Ritlecitinib, an oral JAK3/TEC family kinase inhibitor, had been approved in 2023 as a once-daily oral treatment for individuals with severe alopecia areata aged ≥12 years old.2 The drug has been shown to be impactful and safe among those aged 12 and older with the condition who also experience hair loss of 50% at least, based on data resulting from the ALLEGRO phase 2b/3 trial.


The continuing phase 3 open-label study known as ALLEGRO-LT was designed to assess the safety and efficacy data of ritlecitinib in a long-term analaysis of patients in the age range of 12 years and older, specifically with at least 25% loss of hair. It is a post-hoc assessment of ALLEGRO-LT in which Tziotzios et al. focused on the efficacy of the drug up to the 15-month mark, stratified by the initial extent of hair loss on subjects’ scalps.1

There were 2 cohorts of participants featured in the ALLEGRO-LT trial: subjects who rolled over from the ALLEGRO phase 2a or phase 2b/3 studies, as well as de novo patients in the 12-years and older age bracket with at least 25% loss of hair on the scalp and no prior study participation. The post-hoc evaluation specifically looked at the de novo cohort.

The investigators treated the participants initially with a 4-week loading dose of ritlecitinib 200 mg at a once-per-day dosing regimen. This was then followed by a maintenance dose of 50 mg on a once-per-day basis.

The research team looked at subjects’ median Severity of Alopecia Tool (SALT) scores over time as outcomes for the study, as well as the proportions of participants reporting SALT scores of 20 or less and 10 or less by the 15-month mark. Categorization of the participants used SALT scores for its basis: 25 to <50, 50 to <75, 75 to <90, 90 to <95, and 95 to 100.

The team’s assessment utilized observed data among these patients, noting that among the 1052 who had been enrolled in ALLEGRO-LT, 447 were placed in the de novo arm. Among these de novo patients, the distribution of baseline SALT scores was as follows: 26.6% of these subjects had scores ranging from 25 to <50, 16.8% had scores ranging from 50 to <75, 9.2% had scores ranging from 75 to <90, 2.9% had scores ranging from 90 to <95, and 44.5% had scores ranging from 95 to 100.


Those who had SALT scores of 95 or higher were noted by the investigators as generally having a longer average alopecia episode duration (3.47 years), in addition to their overall duration of their condition (10.86 years), versus subjects showing baseline SALT scores which were below 50 (2.53 and 8.79 years, respectively).

The research team found that decreases in median SALT scores were seen across all cohorts from baseline to the 15-month mark. At this point, the team noted that median SALT scores had been 1.0, 1.2, 1.4, 2.4, and 30.9 among those in the baseline cohorts of 25 to <50, 50 to <75, 75 to <90, 90 to <95, and 95 to 100, respectively.

The investigators showed that 93.0%, 87.7%, 88.2%, 83.3%, and 43.9% of those featured in these respective arms, by 15 weeks, reported SALT scores of 20 or less. Conversely, they noted that 81.0%, 76.9%, 73.5%, 75.0%, and 33.5% had been able to achieve SALT scores of 10 or less.

A greater proportion of individuals who had baseline SALT scores which were under 50, the research team reported, had active shedding of hair at baseline at the point of baseline compared to subjects reporting scores of 95 or higher (49.6% versus 11.6%, respectively).

Following treatment for a total of 15 months with ritlecitinib, the team found that those with less than 95% loss of hair at the point of baseline had generally been successful at near complete regrowth of their scalp hair.

They noted that these subjects’ median SALT scores had been below 2.4. In contrast, they reported that those with baseline hair loss of 95% or greater were shown to have more refractory disease. However, over a third were noted as still achieving meaningful clinical responses by the 15-month mark.

“Overall, ritlecitinib was efficacious in patients with (alopecia areata) with ≥25% hair loss including those with extensive hair loss at baseline,” Tziotzios and colleagues wrote.


  1. Efficacy of ritlecitinib in patients with alopecia areata by extent of hair loss at baseline: post hoc analysis of the phase 3 long-term ALLEGRO-LT study. Revolutionizing Atopic Dermatitis (RAD) 2024 Annual Meeting June 8 – 10, 2024. Chicago, IL.
  2. Smith T. Ahmad Amin, MD: Effects of the FDA Approval of Ritlecitinib for Adolescents with Alopecia Areata. HCPLive. July 18, 2023. https://www.hcplive.com/view/ahmad-amin-effects-fda-approval-of-ritlecitinib-for-adolescents-with-alopecia-areata. Date accessed: June 24, 2024.
Recent Videos
Discussing Post-Hoc Data on Ruxolitinib for Nonsegmental Vitiligo, with David Rosmarin, MD
Signs and Symptoms of Connective Tissue Disease
Connective Tissue Disease Brings Dermatology & Rheumatology Together
What Makes JAK Inhibitors Safe in Dermatology
Potential JAK Inhibitor Combination Regimens in Dermatology
Therapies in Development for Hidradenitis Suppurativa
"Prednisone without Side Effects": The JAK Inhibitor Ceiling in Dermatology
Discussing Changes to Atopic Dermatitis Guidelines, with Robert Sidbury, MD, MPH
How Will Upadacitinib, Povorcitinib Benefit Hidradenitis Suppurativa?
The JAK Inhibitor Safety Conversation
© 2024 MJH Life Sciences

All rights reserved.