Mechanism of Action

ARQ-252 is a topical JAK1 inhibitor that has promise as a novel treatment for inflammatory dermatologic diseases, including hand eczema and vitiligo. Many inflammatory cytokines and other signaling molecules rely on the JAK pathway, and specifically JAK1, which plays a central role in immune system function.  Inhibition of JAK1 has been shown to treat a range of inflammatory diseases, including rheumatoid arthritis, psoriasis, Crohn’s disease, and atopic dermatitis.

ARQ-252 is differentiated from other topical JAK inhibitors by its high potency and unique high selectivity against JAK1 compared to JAK2. ARQ-252’s selectivity for JAK1 may confer important safety advantages compared to other topical JAK inhibitors.

In July 2020, Arcutis announced that it initiated enrollment in the Phase 2b portion of the Phase 1/2b study of ARQ-252 in adult patients with chronic hand eczema. Topline data from this trial are expected in the second half of 2021.