Updated Integrated Safety Analysis of Ritlecitinib Up to Five Years in Patients With Alopecia Areata From the Allegro Clinical Trial Program

November 2025 in “ American Journal of Clinical Dermatology ”

Maryanne M. Senna, Sameh Hanna, Rie Ueki, Xingqi Zhang, Crystal Aguh, Bianca Maria Piraccini, Dalia Wajsbrot, Edward Nagy, Mojgan Sadrarhami, Simon Chen, Robert Wołk, Helen Tran, Alexandre Lejeune

ritlecitinib alopecia areata ALLEGRO clinical trial adverse events opportunistic infections herpes zoster malignancies major adverse cardiovascular events

TLDR Ritlecitinib is generally safe for long-term use in treating alopecia areata.

The updated integrated safety analysis of the ALLEGRO clinical trials evaluated the long-term safety of ritlecitinib in patients aged 12 years and older with alopecia areata over approximately 5 years. The study included 1,294 patients in the any-ritlecitinib group and 1,228 in the ritlecitinib 50 mg ± 200 mg group. Adverse events (AEs) were common, occurring in 87.1% of the 50 mg ± 200 mg group and 89.5% of the any-ritlecitinib group, with headache, positive SARS-CoV-2 test, and nasopharyngitis being the most frequent. Serious AEs were reported in 6.8% of patients in both groups. The incidence rates for opportunistic infections, herpes zoster, malignancies, and major adverse cardiovascular events were low. Overall, the safety profile of ritlecitinib was consistent with previous data, indicating it was generally well tolerated for long-term use in this patient population.