Etanercept-based treatments, including etanercept monotherapy and combination therapy with methotrexate (MTX), are superior to MTX monotherapy in treating patients with psoriatic arthritis (PsA), according to research published in Arthritis and Rheumatology.

The Study of Etanercept and Methotrexate in Subjects with Psoriatic Arthritis (ClinicalTrials.gov identifier: NCT02376790) was a 48-week phase 3, multicenter, randomized, double-blind international study with a 30-day safety follow-up period that enrolled patients at 124 hospitals or clinics across 17 countries. Researchers sought to assess the efficacy of MTX and etanercept monotherapies in PsA and examine the value of combining these therapies to treat this patient population.

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In total, 851 patients (90.7% white, mean age 48.4±13.1 years) were enrolled in the trial. Patients were randomly assigned to one of 3 treatment groups: MTX monotherapy (n=284), etanercept monotherapy (n=284), and MTX plus etanercept combination therapy (n=283).

A total of 691 patients (81.2%) completed the trial. Baseline demographic and disease characteristics were similar across all 3 treatment arms, and mean disease duration of all participants was 3.2±6.3 years.

At 24 weeks, both American College of Rheumatology (ACR) 20% improvement (ACR20) and Minimal Disease Activity (MDA) response rates were significantly higher in patients receiving etanercept monotherapy compared with those who received MTX monotherapy (ACR20 60.9% and MDA 35.9% vs ACR20 50.7% and MDA 22.9%, respectively). These responses were significantly greater still in the combination therapy group (ACR20 65% and MDA 35.7%).

Additional outcomes, including ACR 50% improvement and ACR 70% improvement responses, were higher in the etanercept vs the MTX monotherapy group (44.4% and 29.2% vs 30.6% and 13.8%, respectively) and in the combination group vs the MTX monotherapy group (45.7% and 27.7%).

MDA and ACR improvement responses were similar between the etanercept monotherapy and combination therapy groups as well. Week 48 outcomes, measured via radiographic progression, were similar in the etanercept monotherapy and combination therapy groups compared with the MTX monotherapy group.

Incidences of adverse events leading to treatment discontinuation were similar across the 3 study arms: 75.2%, 67.7%, and 76.1% in the MTX monotherapy, etanercept monotherapy, and combination groups, respectively.

Some limitations of the study were that researchers did not consider axial disease in eligibility criteria, and the included patients primarily had polyarticular disease which limited the generalizability of the results. Additionally, the lack of a placebo group “limits the ability to draw firm conclusions about the efficacy of methotrexate monotherapy.”

“The results of this study demonstrate that etanercept as monotherapy and in combination with methotrexate is superior to methotrexate monotherapy when assessed according to the proportion of patients experiencing ACR20 and MDA responses,” the researchers concluded. “Overall, these results provide information that is of practical value for clinical practice.”

Disclosures: This study was sponsored by Amgen Inc. For a full description of Amgen’s involvement, and a complete list of disclosures, please see the original reference.

Reference

Mease PJ, Gladman DD, Collier DH, et al. Etanercept and methotrexate as monotherapy or in combination for psoriatic arthritis: primary results from a randomized, controlled phase III trial [published online February 12, 2019]. Arthritis Rheumatol. doi:10.1002/art.40851