English version of Japanese guidance for the use of oral Janus kinase inhibitors (JAK1 and TYK2 inhibitors) in the treatments of psoriasis

Abstract

This is the English version of Japanese guidance for the use of oral Janus kinase (JAK) inhibitors (JAK1 and tyrosine kinase 2 [TYK2] inhibitors) in the treatments of psoriasis. Several cytokines, such as interleukin (IL)‐6, IL‐7, IL‐12, IL‐21, IL‐22, IL‐23, interferon (IFN)‐α, and IFN‐γ, are involved in the pathogenesis of psoriasis (including psoriatic arthritis). 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 psoriasis. JAK has four types: JAK1, JAK2, JAK3, and TYK2. Regarding the use of oral JAK inhibitors for the treatment of psoriasis in Japan, indications of the JAK1 inhibitor upadacitinib were extended also to psoriatic arthritis in 2021, and the use of the TYK2 inhibitor deucravacitinib for plaque‐type psoriasis, pustular psoriasis, and erythrodermic psoriasis became covered by health insurance in 2022. This guidance was developed for board‐certified dermatologists who specialize in the treatment of psoriasis and to promote the proper use of oral JAK inhibitors. In the package inserts and guides for appropriate use, upadacitinib and deucravacitinib are classified as a “JAK inhibitor” and a “TYK2 inhibitor”, respectively, and it is possible that there may be differences in safety between the two drugs. The safety of these drugs will be evaluated for the future by the postmarketing surveillance for molecularly targeted drugs for psoriasis of the Japanese Dermatological Association.

Safety and effectiveness of apremilast in Japanese patients with psoriatic disease: Results of a post‐marketing surveillance study

“…In contrast, some biologics and Janus kinase inhibitors used in managing psoriatic disease in Japan may be associated with a higher risk of infections, which requires appropriate screening and monitoring of patients according to recommendations from Japanese guidance. 24,25 Overall, the rates of serious ARs remained low in this study and occurred only in 0.7% (7/1063) of patients, whereas the phase 2b study in Japanese patients reported an AR incidence of 2.4% (2/85 patients), 26 and PROMINENT, a phase 3b study in Japanese patients with mild to moderate PsO, 17 reported a similar incidence (2.6%; 4/152 patients) of serious treatment emergent adverse events (TEAEs).…”

The Role of Sphingolipids and Sphingosine-1-phosphate—Sphingosine-1-phosphate-receptor Signaling in Psoriasis

“…JAK1, JAK2, and TYK2 are known to be involved in cell proliferation [93]. Currently, JAK1 inhibitors and TYK2 inhibitors are approved for psoriasis treatment [94]. As all systemic therapies, including biologic agents and JAK inhibitors, significantly affect the immune system, patients are exposed to various risks, such as bacterial, fungal, and viral infections, during treatment.…”

Treatment patterns of systemic drug use in Japanese patients with plaque psoriasis: A retrospective chart review

“…These systemic drugs alleviated PsO severity and improved the patients' quality of life. [13][14][15] The treatment scheme for Japanese patients with PsO based on the PsO treatment pyramid plan 16 has reached a consensus, and the Japanese Dermatological Association (JDA) has released guidance regarding the use of biologics and Janus kinase inhibitors for PsO 17,18 ; however, there are no comprehensive guidelines regarding systemic drug use for PsO. 13,14 The selection of systemic drugs for each patient among various types of oral drugs or biologics therefore depends on the physician's judgment and patient preference.…”