Non-clinical and clinical pharmacology of the potent and selective RARγ agonist trifarotene. Non-clinical and clinical pharmacology of the potent and selective RARγ agonist trifarotene

Background: First- and third-generation retinoids are the main treatment in acne. Even though efficacious, they lack full selectivity for RARγ expressed in the epidermis and infundibulum. Objectives: To characterize the in vitro metabolism and the pharmacology of the novel retinoid trifarotene. Methods: In vitro assays determined efficacy, potency and selectivity on RARs, as well as the activity on the expression of retinoid target genes in human keratinocytes and ex vivo cultured skin. In vivo studies investigated topical comedolytic, anti-inflammatory and depigmenting properties. The trifarotene-induced gene expression profile was investigated in non-lesional skin of acne patients and compared to ex vivo and in vivo models. Finally, the metabolic stability in human keratinocytes and hepatic microsomes was established. Results: Trifarotene is a selective RARγ agonist with >20-fold selectivity over RAR and RARβ. Trifarotene is active and stable in keratinocytes but rapidly metabolized by human hepatic microsomes, predicting improved safety. In vivo, trifarotene 0.01% applied topically is highly comedolytic and has antiinflammatory and antipigmenting properties. Gene expression studies indicated potent activation of known retinoid-modulated processes (epidermal differentiation, proliferation, stress response, RA metabolism) and novel pathways (proteolysis, transport/skin hydration, cell adhesion) in ex vivo and in vivo models, as well as in human skin after four weeks of topical application of trifarotene 0.005% cream. Conclusion: Based on its RARγ selectivity, rapid degradation in human hepatic microsomes and pharmacological properties including potent modulation of epidermal processes, topical treatment with trifarotene is expected to provide strong efficacy combined with a favourable safety profile in acne and ichthyotic disorders. Overall design: Total of 16 chips. 9 patients : 2 biospies per patient: 1 in non-inflammatory skin of acne patient after vehicle treatment (J27) (Back), 1 in non-inflammatory skin of acne patient after after CD 5789 treatment (J27) (Back)