New therapies for psoriasis and psoriatic arthritis

Purpose of review Over the last several years, novel immunologic pathways pivotal in the development of the pathobiology of psoriasis and psoriatic arthritis (PsA) have been revealed. These discoveries catalyzed a search for new treatment targets resulting in many new therapies that are now available for patients with psoriatic disease. Recent findings Helper T cells that secrete interleukin-17 (TH17) along with CD8+ cells, innate lymphocyte cells, and gamma delta T cells are important in the pathogenesis of psoriasis and PsA. Recently, agents that target interleukin-17, the interleukin-17 receptor, and interleukin-23 (antip19) have been approved or are in clinical trials. Apremilast, a new oral agent, was approved for the treatment of psoriasis and PsA. Secukinumab, an interleukin-17A antibody, has been approved for treatment of psoriasis and PsA in the United States. It is effective with a good safety profile. Ixekizumab, another anti-interleukin-17A antibody, is currently in clinical trials and brodalumab, an interleukin-17 receptor antagonist, was removed from clinical trials because of safety concerns despite demonstrated efficacy in psoriasis and PsA. Targeting interleukin-23 with antibodies to p19 is another approach with encouraging results in psoriasis. Apremilast, an oral agent, approved to treat psoriasis and PsA demonstrates moderate efficacy with an excellent safety record. The role of tofacitinib in psoriatic disease remains to be determined pending a safety review in psoriasis and completion of PsA trials.