Biologics have revolutionized the therapy of the psoriatic disease spectrum. These new classes of drugs also allow deeper insight into the pathogenesis of the disease and highlight the existence of distinct "molecular" disease subgroups as evidenced by the spectrum of clinical response seen. Molecules associated with both the interleukin (IL)-17 and interferon (IFN)γ pathways have important functions in psoriatic inflammation, and both are targeted by drugs acting on the p40 subunit shared by IL-12 and IL-23. These IL-12 family members are upstream of pathways characterized by the production of IFNγ and IL-17 related molecules, including IL-17, IL-22, and CCL20. We here summarize the mode of action and clinical studies of the p40 inhibitor ustekinumab with focus on both psoriasis and psoriatic arthritis.
Keywords: IL-12/IL-23 inhibition; Psoriasis; Psoriatic arthritis; Treatment; Ustekinumab.