Long-term Outcomes of TNF Inhibitors in Psoriatic Arthritis

February 15, 2018

British investigators take a long-range view of tumor necrosis factor inhibitors in patients with psoriatic arthritis.

Reference1. Fagerli KM, Kearsley-Fleet L, Watson KD, et al. Long-term persistence of TNF-inhibitor treatment in patients with psoriatic arthritis. Data from the British Society for Rheumatology Biologics Register. RMD Open. 2018;4:e000596. doi:10.1136/rmdopen-2017-000596

British investigators take a long-range view of tumor necrosis factor inhibitors in patients with psoriatic arthritis. Scroll through the slides for their findings and take-home points.

Randomized, controlled trials suggest that tumor necrosis factor (TNF) inhibitors are effective in psoriatic arthritis, but data on long-term efficacy and tolerability are sparse and the majority of studies on long-term outcomes have been in rheumatoid arthritis (RA). Pathophysiology differences mean that long-term outcomes in RA may not translate to psoriatic arthritis.

What is the long-term efficacy of a first TNF inhibitor in psoriatic arthritis? Which factors are associated with 5-year treatment persistence? And what is the long-term efficacy of second and third TNF inhibitors? A team of British researchers recently addressed these questions.

The study included 625 patients with highly active polyarticular psoriatic arthritis on their first TNF inhibitor within the past 6 months. Outcomes were assessed with questionnaires mailed to patients and providers. Treatment persistence (as a surrogate for long-term efficacy and tolerability) was evaluated at 3, 5, and 8 years. Five years was the cutoff for long-term successful treatment with first TNF inhibitor. The median follow-up was 8.0 years.¹

At 5 years, 46.7% of study participants were still on their first TNF inhibitor.

Five-year treatment persistence was significantly associated with male sex, lack of baseline comorbidity, and use of etanercept or adalimumab.

The persistence of TNF inhibitors in patients with highly active polyarticular psoriatic arthritis is high, especially after they switch to a second or third TNF inhibitor. Note that patients with highly active psoriatic arthritis who have failed a first TNF inhibitor may still benefit from a second or third trial.

The results of this study highlight the challenge of identifying clinical predictors of outcomes for TNF inhibitors in psoriatic arthritis. Factors found in other studies, including concomitant use of methotrexate and high baseline C-reactive protein (CRP) levels, could not be confirmed. Note that there was limited evaluation of comorbidities; the results do not imply the need to restrict access to TNF inhibitors in patients with comorbidities.

What can be gleaned from this British registry study? These key points:
• Persistence of TNF inhibitors at 5 years, a surrogate for successful treatment, is high in patients with highly active polyarticular psoriatic arthritis
• Treatment persistence of second and third TNF inhibitors in patients with inadequate response to a first TNF inhibitor was similarly high, which suggests that these patients may benefit from a second or third trial
• Male sex, lack of comorbidities, and treatment with etanercept or adalimumab were associated with successful therapy, but identifying clinical predictors for outcomes of TNF inhibitors in psoriatic arthritis proves challenging