Effectively Managing Psoriatic Arthritis

Effectively managing psoriatic arthritis requires tailoring treatments to individual patients while taking into consideration other comorbidities and related conditions, such as spondyloarthritis (SpA), inflammatory bowel disease and uveitis.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) has provided evidence-based treatment recommendations to manage psoriasis and psoriatic arthritis, but there is little evidence showing how treatment is affected by common comorbidities.

In a review published in the October issue of Clinical Experimental Rheumatology, Laura C. Coates, MBChB, MRCP, PhD, of the Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, London, addressed the most common treatment protocols used to treat psoriatic arthritis.

The Benefits of Early Treatment and Positive Long-Term Outcomes

Studies have shown that the longer psoriatic arthritis goes untreated, the poorer the long-term outcomes. Researchers have also found the opposite is true:  the sooner the disease is treated after diagnosis, the better the long-term outcomes.

“Tillett et al. identified that a >12 months delay in diagnosis was a significant predictor of functional impairment at 10 years. Haroon et al. found in 283 patients with PsA that patients with more than 6 months of symptoms prior to a diagnosis are more likely to have erosive peripheral joint disease, arthritis mutilans, joint deformity, functional impairment and sacroiliitis, and were significantly less likely to achieve a drug free remission,” Dr. Coates wrote.

She highlighted a large randomized controlled trial of a tumor necrosis factor inhibitor (TNFi) that was used to treat early psoriatic arthritis, which worked as well as the methotrexate response group in the study.

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Treat to target can be especially helpful in newly diagnosed psoriatic arthritis patients. Clinical and imaging studies show that it has been effective in rheumatoid arthritis, specifically, the Tight Control of RA (TICORA) study, which showed a benefit after 18 months despite only using conventional anti-rheumatic drugs (DMARDs) and corticosteroids. (Patients in the tight control arm who continued to have a DAS>2.4 at monthly visits had their DMARD therapy escalated and were given additional systemic or intra-articular steroids up to 120 mg per visit. At the study’s end, 82% of tight control patients met the EULAR good response compared to 44% of controls (p<0.0001). Now, there is evidence showing that treat-to-target works in psoriatic arthritis, Dr. Coates writes.

“There is evidence that treating to target using the MDA (minimal disease activity) criteria can improve outcomes across multiple measures in patients with recent onset PsA,” she wrote.

In the United Kingdom, treat-to-target is recommended as the standard of care for newly diagnosed patients with rheumatoid arthritis patients.

EULAR conducted a large literature review in 2011 to identify treat-to-target research in spondyloarthritis and psoriatic arthritis, but there was no agreement on appropriate targets. The EULAR taskforce recommended remission as the main target for all of spondyloarthritis with low disease activity as an alternative target, Dr. Coates wrote.

Specific definitions for defining “low disease activity” have been developed for the new composite measures psoriatic arthritis (PASDAS, the GRACE index and the CPDAI), but these have not been validated, she wrote.

In a review of treat-to-target treatment protocols for psoriatic arthritis, Dr. Coates highlighted several significant studies: 

The Tight Control of Psoriatic Arthritis (TICOPA) study:  This study is based on a treatment algorithm of methotrexate, combination DMARDs and biologic agents in a step-up design. It includes 206 patients with recent onset psoriatic arthritis who were randomized 1:1 to tight control or standard care. The tight control group was reviewed every four weeks and treatment was escalated if they did not meet the criteria for minimal disease activity. Patients in the standard care group were reviewed every 12 weeks with no limitations on their care. The odds of achieving ACR20, ACR50, ACR70 and PASI75 were significantly higher for the tight control group who also experienced greater improvements in physical function and quality of life, but this group also experienced more adverse events.

Another study, Dr. Coates includes in her review, cites a high rate of relapse. “In one study, 20 of 26 patients had disease recurrence after a mean of just 74 days. In a small pilot study in the UK, 17 patients were randomized 2:1 to treatment withdrawal with six of the 11 flaring within three months and additional patients flaring beyond the follow up time of the trial,” she wrote. But in both studies, the disease was brought under control once the treatments resumed.

Other studies have had more success with dose reductions. In one study, 20 of 10 PsA patients who were taking a biologic experienced no adverse effects after the dosage was reduced. Another study of 102 psoriatic arthritis patients receiving tapered doses of biologic agents, no significant differences were seen in patients taking full or reduced dosages.

Step Up or Step Down?

Research in psoriatic arthritis strategies is limited, particularly in the area of step-up or step-down therapies. While a step-up therapeutic approach is defined as the use of one therapy first, then combined therapies when warranted,  the step-down approach begins with a higher concentration of combined therapies, which are gradually reduced as treatment goals are achieved. Most physicians currently follow a step-up approach to minimize toxicity.

“The potential benefits of early combination or aggressive treatment strategies should be examined in a randomized controlled trial and the associated potential risks of these should be elucidated,” Dr. Coates wrote.

More research needs to be conducted in order to achieve optimal treatment outcomes in psoriatic arthritis, she concluded.

Disclosures:

L.C. Coates is funded by the NIHR as a Clinical Lecturer, and has received research funding and/or honoraria from Abbvie, Boehringer-Ingelheim, Pfizer, UCB, Celgene, Janssen and MSD.

References:

Laura C. Coates, MBChB, MRCP, PhD. "Therapy strategies in psoriatic arthritis,"

Clinical Experimental Rheumatology

. 2015 Vol.33, N°5 ,Suppl.93 - PI 0070, PF 0072