Psoriatic arthritis (PsA) is one of the diseases in the family of spondyloarthritis and is thus related to ankylosing spondylitis. Similar treatments/medications are used for both AS and PsA.

All three of the TNF-a inhibitor medications approved by the FDA for ankylosing spondylitis are also approved for treating psoriatic arthritis: Enbrel®, Remicade® and Humira®.

According to a 2005 article in the journal, Annals of Rheumatic Diseases, this class of medications has "shown excellent clinical results with the tumour necrosis factor (TNF) blockers, etanercept, infliximab, and adalimumab in a variety of domains including the joints, quality of life, function, and slowing of disease progress as evidenced radiologically. In addition, these agents have shown benefit in domains more unique to PsA, such as the skin lesions of psoriasis, enthesitis, and dactylitis, pointing out the similar pathogenesis of the disease in the skin, the tendons, and the synovial membrane."

Now, a new study has examined the possible benefits of switching between these medications if the initial one is found to be ineffective in treating PsA. Because each of the TNF-a inhibitors works somewhat differently - as well as being manufactured differently - it is thought that if one is not beneficial, another might be. This is similar to studies done with TNF-a inhibitors and their use in treating AS.

The study, "Switching tumour necrosis factor antagonists in patients with ankylosing spondylitis and psoriatic arthritis: an observational study over a 5-year period", concludes that, "on a selected population of patients with SpA indicate that the failure of an initial TNF antagonist does not preclude the response to another one." Thus, if one is ineffective, another might be effective in treating PsA.

The study does caution that more trials are needed. The study abstract can be read by clicking here.

For more information on psoriatic arthritis, please visit our PsA section on the website by clicking here.

References:

Annals of the Rheumatic Diseases 2007;66:1393-1397
Annals of the Rheumatic Diseases 2005;64:ii78-ii82

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