Switching JAK Inhibitors Can Benefit Patients with Severe Alopecia

Study finds nearly half of patients with severe alopecia areata achieved meaningful hair regrowth after switching to a second JAK inhibitor.

Published on Feb. 5, 2026

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A new study has found that many patients with severe alopecia areata (AA) can achieve significant hair regrowth by switching to a second JAK inhibitor (JAKi) medication, especially if they had responded to a prior JAKi treatment. The retrospective study of 108 patients showed that 48.8% achieved a clinically meaningful response, defined as a Severity of Alopecia Tool (SALT) score of 20 or less, after switching to a second JAKi. Patients who had responded to their initial JAKi were over three times more likely to respond to the second inhibitor.

Why it matters

Alopecia areata is an autoimmune condition that can cause patchy or total hair loss, significantly impacting patients' quality of life. JAK inhibitors have emerged as an effective treatment, but some patients do not respond or lose effectiveness over time. This study suggests that switching to a different JAK inhibitor can be a viable option for many patients, especially those who had initially responded to treatment.

The details

The study, led by researchers from Lahey Hospital & Medical Center and the University of Massachusetts Chan Medical School, looked at 108 patients with severe AA who had been treated with a JAK inhibitor for at least 6 months before switching to a second JAKi between October 2024 and January 2025. Overall, 66.6% of patients showed some improvement with their first JAKi, but only 35.8% achieved a SALT score of 20 or less. After switching to a second JAKi, 48.8% of patients reached that clinically meaningful response threshold, and 32.6% achieved a SALT score of 10 or less. Patients who had responded to their initial JAKi were over 3 times more likely to respond to the second inhibitor. Adverse events were generally mild, including acne, high cholesterol, and minor infections.

  • The study looked at patients treated between October 2024 and January 2025.
  • The mean duration of alopecia areata among the patients was 12.1 years.

The players

Aubrey Martin, BS

Department of Dermatology, Lahey Hospital & Medical Center, Burlington.

Li-Chi Chen, MD, MPH

Department of Dermatology, University of Massachusetts Chan Medical School, Worcester, Massachusetts.

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What they’re saying

“Our findings support the clinical utility of JAKi switching in select patients with refractory AA, particularly those with a history of response to a prior oral JAKi treatment.”

— Aubrey Martin, BS (Journal of the American Academy of Dermatology)

“Large-scale prospective studies are needed to clarify optimal sequencing strategies, understand mechanisms of variable response, and identify predictors that can inform personalized care.”

— Li-Chi Chen, MD, MPH (Journal of the American Academy of Dermatology)

What’s next

The researchers noted that large-scale prospective studies are needed to further understand the optimal use of JAK inhibitors and identify predictors of response to help guide personalized treatment approaches for patients with severe alopecia areata.

The takeaway

This study provides important evidence that switching to a different JAK inhibitor medication can be an effective strategy for many patients with severe alopecia areata who do not respond or lose effectiveness with an initial JAKi treatment. These findings support the clinical utility of JAKi switching, particularly for patients who have shown prior response to a JAK inhibitor.