English version of Japanese guidance for the use of oral Janus kinase (JAK) inhibitors in the treatments of atopic dermatitis

This is the English version of guidance for the use of oral Janus kinase (JAK) inhibitors in the treatment of atopic dermatitis. Several cytokines, such as interleukin (IL)-4, IL-13, IL-22, IL-31, thymic stromal lymphopoietin, and interferon-γ, are involved in the pathogenesis of atopic dermatitis. As oral JAK inhibitors hinder the JAK-signal transducers and activators of transcription signal transduction routes involved in the signal transduction of these cytokines, they may be effective for the treatment of atopic dermatitis. In Japan, as oral JAK inhibitors for atopic dermatitis, a JAK1/2 inhibitor, baricitinib, expanded its authorized indications for atopic dermatitis in 2020. Consequentially, a JAK1 inhibitor, upadacitinib, also expanded its indications to atopic dermatitis in 2021, followed by new approval of another JAK1 inhibitor, abrocitinib, for the use under the Japanese health insurance system. Physicians who intend to use them should sufficiently understand and comply with contents of guidelines prepared by the Japanese Ministry of Health, Labour and Welfare to promote optimal use of these drugs. In the treatment with oral JAK inhibitors, it is important to sufficiently consider disease factors, treatment factors and patient backgrounds, and share them with patients to choose treatment options. Points to be considered for drug selection include the efficacy and safety of drugs, age of patients, and dosage and administration of the drug. This guidance was developed for board certified dermatologists, who are specialized in the treatment of atopic dermatitis, and for promoting proper use of oral JAK inhibitors, taking into account a variety of factors in individual patients.