Apremilast for RAS

Apremilast is an oral small-molecule inhibitor of phosphodiesterase (PDE) 4 that works intracellularly to modulate a network of pro-inflammatory and anti-inflammatory mediators. PDE 4 is a cyclic adenosine monophosphate (cAMP)-specific PDE and the dominant PDE in inflammatory cells. PDE4 inhibition elevates intracellular cAMP levels, which in turn down-regulates the inflammatory response by modulating the expression of TNF-alfa, IL-23, IL-17 and other inflammatory cytokines. Cyclic AMP also modulates levels of anti-inflammatory cytokines such as IL-10. Apremilast has immunomodulatory activity and, therefore, has the potential to be effective in the treatment of RAS.