Lifitegrast, a Lymphocyte Function‐Associated Antigen‐1 Antagonist Demonstrates Beneficial Effect in Psoriasis

ABSTRACT Lifitegrast is a lymphocyte function‐associated antigen‐1 (LFA‐1) antagonist, which is approved for treatment of dry eye disease. In this work we explored the effect of lifitegrast in imiquimod induced psoriasis model in mice. Lifitegrast (5% solution) was tested in imiquimod‐induced psoriasis model in C57 mice. Lifitegrast was topically administered twice a day to the psoriatic skin for 6 days and epidermal skin thickness, psoriasis area and severity index (PASI) score and inflammation markers were assessed. Lifitegrast inhibited the imiquimod‐induced increase in the epidermal thickness, histopathological changes and PASI score. This decrease in psoriasis inflammation was accompanied by decrease in TNF‐α, IL‐6, IL‐22 and IL‐17/IL‐23 axis gene expression in the skin, and the effect is comparable to the oral cyclosporine A(5 mg/kg, twice a day) treatment. Lifitegrast demonstrated significant anti‐inflammatory activity, mainly through reduction in cytokine gene expression related to psoriasis and decreased the severity of psoriasis in vivo. The significant effect shown by this LFA‐1 and ICAM‐1 antagonist indicates a novel topical treatment for psoriasis.