Janus kinase inhibitors look promising in the treatment of severe alopecia areata, particularly in adolescents, said Lucy Yichu Liu, MD, and Brett Andrew King, MD, of Yale University, New Haven, Conn.

Standard medical therapies for alopecia areata – usually topical or injected corticosteroids and allergic contact sensitization – are not very effective for severe disease, particularly alopecia totalis and alopecia universalis. The Janus kinase (JAK) pathway recently has been suggested as a target for treatment.

Dr. Liu and Dr. King reviewed several studies, including a retrospective cohort study of 13 patients aged 12-17 years, in which 7 patients had 100% hair loss and 6 had 20%-70% scalp hair loss. The adolescents were treated with the JAK1/3 inhibitor tofacitinib citrate 5 mg twice daily for 2-16 months (median, 5 months). That led to 93% median improvement in Severity of Alopecia Tool (SALT) score (range, 1%-100%) from baseline. Nine patients experienced hair regrowth. There were mild adverse effects, such as upper respiratory infections and headaches.

In an open-label study of 66 adults with severe alopecia areata, alopecia totalis, or alopecia universalis who received 5 mg of tofacitinib twice daily for 3 months, 64% had some hair regrowth, and 32% had a SALT score improvement of greater than 50%. Patients who had alopecia totalis or alopecia universalis of longer than 10 years were less likely to respond to treatment. Again, adverse effects were most often upper respiratory infections and headaches.

In a retrospective cohort study of 90 adults taking tofacitinib at a dosage of 5-10 mg twice daily for 4 months or longer with or without prednisone (300 mg once monthly for three doses), patients were divided into those who were more or less likely to respond based on duration of disease. Of 65 patients with alopecia totalis, or alopecia universalis that had lasted 10 years or less, or alopecia areata, 77% had some hair regrowth; 58% had more than 50% improvement from baseline, and 20% achieved full regrowth of hair, Dr. Liu and Dr. King reported in the Journal of Investigative Dermatology Symposium Proceedings .

“Given the finding in adults that complete scalp hair loss for more than 10 years is less likely to respond to treatment, there may be merit to pursuing treatment, even if only intermittently, in adolescents or even younger patients with stable, severe alopecia areata, to prevent irreversible hair loss in the future,” they wrote.

A patient with alopecia universalis achieved partial scalp hair regrowth and complete eyebrow regrowth with compounded ruxolitinib, a topical JAK inhibitor, according to a 2016 case report. Dr. Liu and Dr. King reported that clinical trials with topical JAK inhibitors, including topical tofacitinib and topical ruxolitinib, currently are ongoing.

SOURCE: Liu LY et al. J Investig Dermatol Symp Proc. 2018 Jan. doi: 10.1016/j.jisp.2017.10.003 .