What's New in Psoriatic Arthritis

Feb 14, 2018

An expanded role for MRI and 2 recently approved treatment options.

References1. Maldonado-Ficco H, Sheane BJ, Thavaneswaran A, et al. Magnetic resonance imaging in psoriatic arthritis: a descriptive study of indications, features and effect on treatment change. J Clin Rheumatol 2017;23:243-245. doi: 10.1097/RHU.0000000000000558.2. Gladman M, Rigby W, Azevedo VF, et al. Tofacitinib for psoriatic arthritis in patients with an inadequate response to TNF inhibitors. N Engl J Med. 2017;377:1525-1536. doi: 10.1056/NEJMoa1615977.3. Mease PJ, Gottlieb AB, van der Heijde D, et al. Efficacy and safety of abatacept, a T-cell modulator, in a randomised, double-blind, placebo-controlled, phase III study in psoriatic arthritis. Ann Rheum Dis. 2017;76:1550-1558. doi: 10.1136/annrheumdis-2016-210724.

Highlights of 3 recent studies in psoriatic arthritis (PsA) include: MRI is useful in evaluating patients with active disease; tofacitinib can reduce disease activity in patients with an inadequate response to tumor necrosis factor (TNF) inhibitors; and abatacept shows benefit for patients with PsA.[1-3] Scroll through the slides for the latest findings and take-home messages. (©Gemalbarra/Shutterstock.com)

MRI can be used to evaluate patients with active psoriatic arthritis, particularly when inflammation is suspected and radiographic findings are unhelpful.

A study included 168 MRI scans (135 axial and 33 peripheral scans) that had been performed on 125 patients (median age, 50.5 years).[1] Most of the axial scans were performed on the whole spine.

Of the axial MRI scans, the predominant indications were for suspected inflammatory disease (51.1%). Of the extremity MRI scans, the main indications were to identify suspected subclinical synovitis (78.8%).

"We detected low prevalence of bone edema on axial MRI and low prevalence of erosions in peripheral MRI," stated the researchers, led by HernÃ¡n Maldonado-Ficco, MD, of the University of Toronto Psoriatic Arthritis Clinic, Toronto Western Hospital. "In some cases, it can be used as an adjunct to clinical examination in determining treatment change."

The oral Janus kinase inhibitor tofacitinib is more effective than placebo in reducing disease activity in patients with active psoriatic arthritis who had had an inadequate response to TNF inhibitors.

In a 6-month placebo-controlled, double-blind, phase 3 trial, 395 patients were randomly assigned to 4 regimens: 5 mg of tofacitinib administered orally twice daily (132 patients); 10 mg of tofacitinib twice daily (132 patients); placebo, with a switch to 5 mg of tofacitinib twice daily at 3 months (66 patients); or placebo, with a switch to 10 mg of tofacitinib twice daily at 3 months (65 patients).[2]

At 3 months, the rates of at least 20% improvement according to the criteria of the American College of Rheumatology (ACR20) response were 50% with the 5-mg dose of tofacitinib and 47% with the 10-mg dose as compared with 24% with placebo. A disability index indicated larger mean changes from baseline with tofacitinib compared with placebo.

Tofacitinib was more effective than placebo over 3 months in reducing disease activity. Adverse events were more frequent with tofacitinib than with placebo. These adverse events (serious infection, herpes zoster, elevated lipids) are those seen previously in rheumatoid arthritis and psoriasis, the researchers stated.

Abatacept, a selective T-cell costimulation modulator used for rheumatoid arthritis, was approved for psoriatic arthritis (PsA) in the United States and in Europe.

A double-blind, placebo-controlled, phase 3 study in PsA randomly assigned subcutaneous abatacept 125 mg (213 patients) or placebo (211 patients) for 24 weeks, followed by open-label subcutaneous abatacept.[3]

Abatacept significantly increased ACR20 response versus placebo at week 24 (39.4% vs 22.3%). The drug also increased Health Assessment Questionnaire-Disability Index response rates, but this reduction from baseline was not statistically significant.

"The benefits of abatacept were seen in ACR20 responses regardless of TNF inhibitor exposure and in other musculoskeletal manifestations, but significance could not be attributed due to ranking below Health Assessment Questionnaire-Disability Index response in hierarchical testing," stated the researchers, led by Philip J. Mease, MD, of the University of Washington in Seattle. There was only a modest impact on psoriasis lesions, they noted.