LEO 32731

LEO 32731 is an investigational topical small molecule Janus kinase (JAK) inhibitor being developed by LEO Pharma for the treatment of mild to moderate atopic dermatitis. As a 'soft' JAK inhibitor, it is designed to be metabolically unstable in the systemic circulation, thereby limiting systemic exposure and potential side effects while maintaining therapeutic activity at the site of application. The drug targets the JAK-STAT signaling pathway, which is crucial for the signaling of pro-inflammatory cytokines such as IL-4, IL-13, and IL-31 that drive the pathogenesis of atopic dermatitis. By inhibiting these pathways, LEO 32731 aims to reduce skin inflammation and pruritus. It has been evaluated in Phase 1 clinical trials using an intra-individual split-body design to compare its efficacy and safety against a vehicle cream.