JAK1 inhibitor suspension (ARQ-255)


ARQ-255 is an alternate formulation of our JAK1 cream (ARQ-252) being investigated as a treatment for alopecia areata.

Janus kinase 1 (JAK1) inhibitor suspension (ARQ-255) is modified to deliver the drug deep into the dermis and is being investigated for the treatment of alopecia areata.

Alopecia areata

Topical JAK1 inhibitor suspension (ARQ-255) in alopecia areata.

Clinical landscape

  • Alopecia areata is a nonscarring type of hair loss that may present in patches or a complete absence of body and scalp hair1 
  • There are limited approved therapies to treat alopecia areata2,3
  • Because of unpredictable and spontaneous remission, optimal duration of therapy and therapeutic dosing regimens have not been well characterized2,3

Proposed MOA

  • Inhibition of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is a promising target for the treatment of alopecia areata4
  • ARQ-255 is a selective, highly potent,* topical, small-molecule JAK1 inhibitor formulated to deliver the drug deep into the dermis that is being investigated for the treatment of alopecia areata5

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

MOA = mechanism of action

Clinical programs

Phase 1

A phase 1 clinical trial of the topical JAK1 inhibitor suspension (ARQ-255) for the treatment of alopecia areata is ongoing.


1. Strazzulla et al. J Am Acad Dermatol. 2018;78:1-12. 2. Wagner. J Invest Derm Symp Proc. 2015;17:67-69. 3. Fricke and Miteva. Clin Cosmet Investig Dermatol. 2015;8:397-403. 4. Triyangkulsri and Suchonwanit. Drug Des Devel Ther. 2018;12:2323-2335. 5. Data on File. Arcutis Biotherapeutics, Inc.

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 12/2023 to the best of the Company’s knowledge and Arcutis assumes no obligation to update this information.

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