New targets in psoriatic arthritis.

PsA is an immune-mediated chronic inflammatory disease that affects both skin and joints; it is a heterogeneous disease characterized by synovitis, enthesitis, dactylitis and spondylitis. The impact on patients and the burden of disease are substantial. For assessment of the disease, patient-reported outcomes are increasingly important. Conventional therapy consists of NSAIDs, local and systemic CSs, and synthetic and biological DMARDs. While MTX, LEF, SSZ and CYC are the synthetic drugs mainly used, TNF-α blocking agents have represented the majority of biologics used in the last decade (infliximab, etanercept, adalimumab, certolizumab and golimumab). Treat-to-target strategies have been used successfully in PsA. This review concentrates on new developments, mainly covering biologic agents with an IL-17 inhibitor (secukinumab) and an anti-IL-23 agent (ustekinumab), but also synthetic drugs, including a novel phosphodiesterase-4 inhibitor (apremilast) and a Janus kinase inhibitor (tofacitinib) that blocks mainly Jak3 and Jak1 and, to a lesser extent, Jak2. The efficacy of some of these new agents may be even better for the skin than for the joints.