JAK1 inhibitor overview

In development for alopecia areata, chronic hand eczema, and vitiligo.


The active ingredient in ARQ-252 and ARQ-255 is a selective and highly potent* topical janus kinase 1 (JAK1) inhibitor.1

  • The JAK1 inhibitor in ARQ-252 and ARQ-255 demonstrates greater potency for JAK1 than JAK2
  • ARQ-252 is a cream formulation being investigated for the treatment of chronic hand eczema and vitiligo
  • ARQ-255 is formulated as a suspension, designed to deliver the drug deep into the dermis, and will be investigated as a treatment for alopecia areata

*In vitro data. Clinical efficacy claims cannot be made.

Role of JAK1 in immunomodulation

JAK-dependent cytokines contribute to immunodermatologic conditions.2,3

Selective JAK1 inhibition modulates cutaneous immunology pathways

Selective JAK1 inhibition modulates or reduces the activity of specific cytokines while maintaining other JAK-dependent immunomodulatory pathways.2

IFN = interferon, IL = interleukin, JAK = janus kinase, Tyk = tyrosine kinase.


1. Data on File. Arcutis Biotherapeutics, Inc. 2. Schwartz et al. Nat Rev Drug Discov. 2017;17:78. 3. Fragoulis et al. Rheumatology (Oxford). 2019;58:i43-i54.

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This website is intended for US healthcare professionals only. There may be information included that pertains to an investigational therapy or formulation that has not yet been approved for use in your country. The safety and efficacy of investigational therapies and/or formulations and/or uses have not been established. There is no guarantee that the agents will receive health authority approval or become commercially available in any country for the uses being investigated. This information is as of 7/2024 to the best of the Company’s knowledge and Arcutis assumes no obligation to update this information.

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