Introduction
For many years, psoriatic arthritis (PsA) treatment was the poor little brother of rheumatoid arthritis (RA) therapeutics. The older brother would get new clothes and shoes almost every year, but the younger child would have to be content with hand-me-downs.
Likewise, for RA, novel antirheumatic agents were developed in large clinical trial programs at a breakneck pace. But only once their efficacy was formally established in RA, and usually after the drug had been brought to market, did clinical trial programs in PsA get under way—seemingly as an afterthought. And indeed, many of the conventional and biologic disease-modifying antirheumatic drugs (DMARDs) that were approved for RA demonstrated efficacy in PsA as well and received formal approval. But again, this was usually after several years' delay.
All of a sudden, things have changed. A novel small-molecular agent with a unique mode of action, apremilast, has been approved for PsA—and for psoriasis as well—but with no prior experience in RA to speak of. Several biologics targeting the interleukin (IL)-17/23 pathway have been approved for psoriasis; one of these, ustekinumab, has been approved for PsA, and large clinical trial programs are under way with two other ones, secukinumab and ixekizumab. These developments have cast therapeutics for PsA into the rheumatologic spotlight, and we are likely to see very interesting developments over the next several years.
Conventional Treatment for PsA
First-line treatment for patients with milder forms of PsA can be nonsteroidal anti-inflammatory drugs, but as is the case in RA, these do not prevent damage and are therefore inappropriate as the sole therapy for patients with more severe forms of the disease. Corticosteroid injections and even short courses of oral steroids can be used as temporary measures, or for the management of simple flares in one or a few joints.
For patients with an "RA-like" form of PsA, the use of conventional DMARDs, although not supported by solid data from randomized trials, is nonetheless reasonable, and practical experience strongly suggests that such agents as methotrexate, sulfasalazine, and cyclosporine A can all be used with some efficacy in some patients. Some of these are also standard systemic therapies for psoriasis, and for patients with moderate or severe disease in both the skin and the joints, coordination with a dermatologist is often very helpful.
Among the conventional DMARDs, leflunomide is the only agent supported by a large randomized controlled trial in PsA,[1] and this agent could certainly be considered.
For oligoarticular and spinal forms of PsA, conventional agents have been studied very little but are considered much less effective on the basis of clinical experience.
Anti-TNFs for PsA
All of the anti-tumor necrosis factor (TNF) agents that have been approved for RA have been approved for PsA as well. They have all shown very good efficacy compared with placebo, and their safety profile has been well established over the 15 years since the first ones were introduced into rheumatology. They are all effective for management of joint symptom and spinal symptoms, but their efficacy for the more PsA-specific manifestations, enthesitis and dactylitis, is not entirely clear. Dosing recommendations for peripheral and spinal PsA are the same as for RA and for ankylosing spondylitis, respectively.
Medscape Rheumatology © 2015 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Ronald F. van Vollenhoven. The Latest on Treating Psoriatic Arthritis - Medscape - Jul 15, 2015.
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