Tapinarof, a novel, first-in-class small-molecule topical therapeutic aryl hydrocarbon receptor (AhR) modulating agent (TAMA), is in clinical development for the treatment of psoriasis and atopic dermatitis. The efficacy of tapinarof in psoriasis is attributed to its specific binding and activation of AhR, a ligand-dependent transcription factor, leading to the downregulation of pro-inflammatory cytokines, including interleukin-17, and regulation of skin barrier protein expression to promote skin barrier normalization. AhR signaling regulates gene expression in immune cells and skin cells, and has critical roles in the regulation of skin homeostasis. Tapinarof-mediated AhR signaling underlies the mechanistic basis for the significant efficacy and acceptable tolerability observed in early phase clinical trials of tapinarof cream in the treatment of psoriasis
