Apremilast for the treatment of psoriatic arthritis.

Psoriatic arthritis occurs in about one-third of patients with psoriasis, and is a severely disabling, progressive inflammatory spondyloarthropathy typically treated with non-steroidal anti-inflammatory drugs, disease-modifying anti-rheumatic drugs, TNF-α inhibitors and ustekinumab. These medications moderately improve the arthritis, dactylitis, and enthesitis that characterize psoriatic arthritis, however, they are associated with serious long-term adverse effects, issues with safety and tolerability, and high cost. Moreover, many patients do not respond or have resistant or recurrent manifestations to these agents. Apremilast is an orally available phosphodiesterase type 4 inhibitor that may block the pathogenic inflammatory Th17 and Th1 pathways upstream of current biologics, which target extracellular molecules of the immunological response.