A 5-year analysis of the phase III ALLEGRO-LT study, presented at EADV 2026, shows that patients with the least baseline scalp hair loss respond best and fastest to the Janus kinase (JAK) inhibitor ritlecitinib.
At 6 months, 76.3 percent of patients with baseline scalp hair loss of 25 to <50 percent achieved a SALT* score of ≤20. Concurrently, 61.2 percent of those with 50 to <95 percent hair loss also achieved this score, and 22.5 percent of those with nearly complete hair loss (95 to 100 percent) achieved the same score.
At 12 months, 86.4 percent, 72.9 percent, and 34 percent of patients in each group, respectively, achieved this clinically meaningful hair regrowth target. Thereafter, the results plateaued. At the 5-year follow-up, 85.6 percent, 79.1 percent, and 37.5 percent had met the target. [EADV 2026, abstract LB-208]
New insights for clinicians
Dr Brett King of Dermatology Physicians of Connecticut, Fairfield, Connecticut, US, noted that clinicians typically prescribe JAK inhibitors to patients with alopecia areata when hair loss is at least 50–100 per cent. In the last observation carried forward (LOCF) data from a post hoc analysis of patients with at least 25 percent hair loss at baseline, “good responses to ritlecitinib were observed across the spectrum of severity.”
Dr Brett KingThe ALLEGRO-LT trial enrolled patients from both the ALLEGRO phase IIb and III studies, as well as new participants with at least 25 percent scalp hair loss who had not previously received ritlecitinib and had experienced a hair-loss episode within the past 10 years. King presented results for new ritlecitinib starters.
Patients were stratified by baseline SALT score: 118 had a SALT score of 25 to <50, 129 had a SALT score of 50 to <95, and 200 had a SALT score of 95 to 100.
The researchers also tracked the percentage of patients achieving a higher-bar SALT score of ≤10. At 5 years, 73.7 percent, 70.5 percent, and 33 percent of patients with the least, middle, and worst baseline hair loss achieved this endpoint. Responses were higher and faster at 6 months, then plateaued after 12 months.
Safety in de novo cohort
“Regarding the safety of ritlecitinib in this cohort at 5 years, we observed no new findings compared with the larger patient group,” reported King. Adverse events occurred in 89.7 percent (n=401) of patients, with serious adverse events in 6.9 percent and severe adverse events in 7.6 percent. He added that there was one death from breast cancer, unrelated to the drug. Other side effects included headache, nasopharyngitis, upper respiratory infection, fever, acne, fatigue, and cough.
When asked by Dr Electra Nicolaidou from the National and Kapodistrian University of Athens, Greece, whether herpes zoster is a problem in patients with alopecia areata, King said: “There’s only one risk that is quantifiable with this medicine, and that is herpes zoster — actually, it doesn’t matter which [JAK inhibitor] we’re talking about.”
He clarified that the risk could be very low and vary greatly between a 60-year-old and a 20-year-old. However, King advised that all adults starting immunomodulatory therapy should receive a herpes zoster (shingles) vaccination as a precaution.