682 Characterization of a novel selective non-steroidal glucocorticoid receptor agonist with low systemic exposure and reduced potential for skin atrophy

Abstract

Topical glucocorticoids (GCs) are widely used drugs in dermatology but are associated with both local and systemic adverse effects. With the aim to provide an effective but safer topical treatment, we here describe LEO 134310, a novel non-steroidal glucocorticoid receptor (GR) agonist with low systemic exposure and reduced potential for induction of skin atrophy. LEO 134310 is a full GR agonist with high affinity for GR and nanomolar potency in human PBMCs. Furthermore, selectivity for GR was demonstrated within a panel of nuclear hormone receptors, including the mineralocorticoid receptor, which has been associated with induction of skin atrophy. Topical treatment with LEO 134310 in human skin explants resulted in full agonism, measured by GR target engagement, with maximal effects comparable to BMV and CP, although at higher dosage strength. The lower potency of LEO 134310 in human skin explants could be explained by a combination of lower skin penetration, metabolism in the skin and in vitro potency. LEO 134310 was rapidly deactivated in the blood and other compartments by enzymatic hydrolysis, leading to low systemic exposure of active parent compound. Consequently, a 10-fold higher therapeutic index was achieved with LEO 134310 compared to BMV and CP in the TPA-induced skin inflammation mouse model. Induction of skin atrophy after topical treatment with LEO 134310 in minipigs was minimal in contrast to significant epidermal thinning induced by treatment with CP and BMV. In conclusion, LEO 134310 may potentially offer an improved topical treatment solution for patients with inflammatory skin diseases.