Effective treatment of refractory alopecia areata in pediatric patients with oral abrocitinib

Abstract

Alopecia areata (AA) is a T–cell–mediated autoimmune disease of the hair follicle destruction, characterized by non-scarring hair loss, which seriously affects patients' psychosomatic health and quality of life, especially for children and their parents.1 People have tried various treatments, but the curative effect is minimal. Abrocitinib is a highly selective JAK1 inhibitor recently launched. Here, we report a case of refractory alopecia areata in a child who was treated with abrocitinib and improved. The patient, an 11-year-old male, presented with patchy diffuse alopecia on the head for more than 6 years, with recurrent attacks and a chronic course. Previously healthy, there were no similar symptoms in his family. Previous treatments included topical and oral corticosteroids, topical minoxidil, systemic compound glycyrrhizic acid, and traditional Chinese medicine, but the effect was not good. Physical examination showed that hair loss spots with different sizes and clear boundaries were positive in the hair light pull test and normal scalp (Figure 1A). Laboratory tests showed blood routine, liver and kidney function, antinuclear antibody spectrum, serum thyroid-stimulating hormone, free triiodothyronine, free thyroxine, Mycobacterium tuberculosis (T-SPOT), and hepatitis B were all negative. As conventional medical therapy failed to alleviate the disease, we considered the use of ibrutinib. Then, the patient was given oral abrocitinib 100 mg once a day. After 4 months of treatment, hair regrowth occurred in the affected area of the scalp (Figure 1B). The alopecia areata has improved, and the treatment with abrocitinib is continued. Patients have been regularly followed up, and laboratory examinations and no adverse reactions have been found so far. Alopecia areata is a common chronic autoimmune disease with higher incidence and severity in children than in adults.2 The pathogenesis of AA is complex, IFN-γ and γ-chain (γc) cytokines (such as IL-2, IL-7, and IL-15) are two key drivers of alopecia areata, and these cytokines pass through JAK (Janus kinase). The JAK/STAT pathway mediate the autoimmune attack of CD8+ T cells on hair follicles, leading to the production of AA.3 The treatment of AA remains a challenging problem; currently, there is no specifically approved treatment for AA. Common treatments include topical, subcutaneous, or systemic corticosteroids, topical minoxidil, topical contact immunotherapy, and systemic immunosuppressive agents. However, the curative effect is limited, the risk of adverse reactions is high, and the recurrence rate is high, especially for patients with refractory AA. In recent years, JAK inhibitors have developed rapidly, and the use of Janus kinase inhibitors (JAKIs) may be a promising therapeutic strategy for the treatment of refractory alopecia areata. Geng et al. reported five preschool patients with refractory AA who were treated with oral tofacitinib (pan-JAK inhibitor) and significantly improved after 6 months.4 In a recent study, 11 patients with refractory AA were treated with baricitinib (JAK1/2 inhibitor), and 27% of patients achieved SALT 50 with twice-daily oral baricitinib (2 mg dose).5 These successful attempts suggest that JAK inhibitors can be used in refractory AA, and have achieved good results. In our case, the patient's condition improved 4 months after the initiation of treatment with abrocitinib. To our knowledge, this is the first case of pediatric refractory AA treated with abrocitinib, a highly selective JAK1 inhibitor approved by the US Food and Drug Administration (FDA) for refractory AA in adults with moderate to severe atopic dermatitis. JAK1 is involved in the signaling of γc receptor cytokines (IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21) and IFN-γ.3 These cytokines are the main key factors in the pathogenesis of AA, so we use abrocitinib to treat AA, probably because it covers the cytokines in AA pathophysiology. This case suggests that axitinib may be an alternative treatment for children with refractory AA who fail to respond to conventional therapy. Further prospective studies are needed to evaluate its efficacy and safety. This study was supported by the National Natural Science Foundation of China (Project number: 82060574). The authors declared no conflicts of interest. Ethical approval was not applicable. Patients provided informed consent for the disclosure of details and images of their cases. Not applicable.

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