JAK Inhibitors Effective, Safe for Alopecia Areata in Real-World Settings

Janus Kinase (JAK) inhibitors are both efficacious and safe for treatment of patients with alopecia areata in real-world settings, new findings suggest, although additional prospective studies may be needed to optimize guidelines for use.1

This retrospective analysis—authored in part by Sophie C. Van Helmond, of Erasmus MC University Medical Center Department of Dermatology in the Netherlands—was conducted to evaluate the real-world results of using JAK inhibitors (JAKi) for severe alopecia. Van Helmond and the other investigators noted that recent real-world research had already begun to explore JAK inhibitors’ efficacy and safety among patients with severe alopecia areata.2

“However, comprehensive real-world data on JAKi treatment outcomes remain limited,” Van Helmond and colleagues wrote.1 “This single-centre retrospective study aims to assess the real-world effectiveness and safety of JAKi for hair regrowth in [alopecia areata] patients treated at the Erasmus Medical Center.”

The investigative team at Erasmus University Medical Center in Rotterdam carried out this retrospective, single-center analysis within the Center's Department of Dermatology. In their review, the team looked at individuals with alopecia areata diagnoses.

These trial subjects would include individuals with alopecia subtypes, including alopecia universalis (AU), alopecia totalis (AT), and ophiasis (AO), who were treated with a JAK inhibitor. Specifically, they would have been given ritlecitinib, abrocitinib, baricitinib, upadacitinib, or tofacitinib in the period between December 2017 - February 2024. Most of these participants were also shown to have coexisting atopic dermatitis.

Demographic and baseline clinical data were gathered by the investigatrs, including an assessment of response to treatment that took place at 3-month intervals (±1 month) within the initial year and every 6 months (±3 months) in the second year and beyond. Outcomes to treatment with JAKi were evaluated both qualitatively, using categories of hair regrowth (“substantial regrowth,” “non-substantial regrowth,” and “no regrowth”), and quantitatively via the Severity of Alopecia Tool (SALT) score assessment of scalp hair loss.

The investigative team decided, in cases where SALT scores were not recorded in follow-up interactions, that 2 clinicians would make an estimation of the score through a photographic review. SALT scores, if photographic documentation included fewer than 3 quadrants of patients' scalps, were marked by the team as missing.

The average age of study participants was noted by the team as 34 years, with the mean duration of alopecia areata being 8 years. At the 3, 6, 9, 12, and 18-month marks, the investigators observed substantial regrowth of scalp hair in 25%, 38.9%, 34.7%, 30.6%, and 26.4% of trial subjects, respectively. The team further found that over a median follow-up of 16 months, 61% of the participants had attained significant regrowth. They also noted a median time to response of 7 months.

Cumulative rates of hair regrowth at the 3, 6, 9, and 12-month marks were shown by the investigators to be 11.1%, 40.2%, 55.6%, and 59.7%, respectively. In 1 notable finding, they highlighted that among subjects who had shifted therapies as a result of initial lack of response, 75% eventually experienced significant hair regrowth.

In their safety analysis, the research team noted gastrointestinal symptoms among 25% of subjects and acne among 20.8%. Among 12.5%, the team highlighted rash or pruritus occurrences. Mild infections, including upper respiratory tract infections, were noted by the investigators in 30.6% of participants.

They further expressed that 11.1% of subjects reported occurrence of infections that necessitated treatment, including urinary, respiratory, and gastrointestinal infections. They also identified cases of herpes zoster and herpes simplex. There were 2 serious adverse events—sickle cell crisis and renal failure in an individual with pre-existing kidney dysfunction—that resulted in hospitalization.

“Despite limitations inherent in its retrospective design, such as missing data and variability in documentation, this study provides valuable insights into the practical application of JAKi,” they concluded.1 “Future prospective research is needed to optimize long-term management, identify prognostic factors, and evaluate the impact of these treatments on patient quality of life.

References

1. Van Helmond SC, Willaert M, Nguyen VH, Nijsten T, Waalboer-Spuij R, Hijnen D. Real-world Effectiveness and Safety of Janus Kinase Inhibitors in Alopecia Areata: A Retrospective Cohort Study of 72 Patients. Acta Derm Venereol. 2025 Apr 7;105:adv42990. doi: 10.2340/actadv.v105.42990. PMID: 40192430.

2. Vignoli CA, Gargiulo L, Ibba L, Balato A, Barbareschi M, Barruscotti S, et al. Baricitinib for the treatment of severe alopecia areata: results from a 52-week multicenter retro-spective real-world study. J Dermatolog Treat 2025; 36: 2444494. https://doi.org/10.1080/09546634.2024.2444494.