A 1-year course of methotrexate (MTX) in clinically suspected arthralgia may prevent the development of rheumatoid arthritis (RA) in at-risk individuals who test negative for anti-citrullinated protein antibody (ACPA), according to 4-year results from the TREAT EARLIER study.

While 2-year data did not show a preventive effect, researchers risk-stratified patients in this most recent data. The previous study also grouped all individuals together, while this new analysis separated patients by seropositivity.

“Heterogeneity in risk of rheumatoid arthritis development in ACPA–negative participants with clinically suspect arthralgia might have concealed a treatment effect due to dilution,” wrote senior author Annette H. van der Helm-van Mil, MD, PhD, professor of rheumatology at Leiden University Medical Center, Leiden, the Netherlands, and colleagues. “Therefore, risk-stratified analyses are required to adequately assess the possibility of prevention of rheumatoid arthritis in people with clinically suspect arthralgia who are ACPA–negative.”

To qualify for the study, participants needed to have recent-onset joint pain that a treating rheumatologist suspected of progressing to RA. Second, participants had to have subclinical joint inflammation, detected via MRI.

These are “promising results” for a group where predicting risk for RA has been more difficult than for their ACPA–positive counterparts, said Kevin Deane, MD, PhD, a professor of medicine and rheumatologist at the University of Colorado School of Medicine, Aurora, Colorado, who was not involved with the study. However, additional research is necessary to investigate these findings.

The clinical utility of this finding is also unclear, he noted, as it would be an “extensive process” for all ACPA–negative individuals with joint pain to undergo MRI screening, he continued.

“It’s hard to find people who would meet these criteria, and healthcare systems need to understand how ultimately this could be implemented in clinical care,” he said.

Adding Risk Stratification

The TREAT EARLIER trial included 236 participants; nearly two thirds were women, and 77% were ACPA–negative (specifically for anti-cyclic citrullinated peptide 2). Patients randomly assigned to active treatment received a single intramuscular glucocorticoid injection (methylprednisolone 120 mg) upon inclusion and then completed a 1-year course of MTX. The comparator group received a single placebo injection at the beginning of the trial and a 1-year course of placebo tablets. All trial screenings and visits were conducted at the Leiden University Medical Center.

At the 2-year mark, there was no difference in the development of RA between the treatment and placebo groups, although there was improvement in joint pain, physical functioning, and MRI-detected joint inflammation in all at-risk groups given MTX — ACPA–positive patients and those at high risk for clinical arthritis development.

MTX delayed the onset of RA, with a statistically significant difference between treatment and placebo at 6 and 12 months, but not at 24 months.

For this 4-year analysis, published in The Lancet Rheumatology, authors stratified patients at their time of enrollment according to their risk of developing RA based on a published model for predicting inflammatory arthritis. Predictors included ACPA positivity (2 points), rheumatoid factor positivity (1 point), more than two locations of subclinical inflammation on MRI (2 points), and presence of metacarpophalangeal extensor tenosynovitis on MRI (1 point).

Patients with at least 4 points were classified as “high-risk,” with a 70% or higher predicted risk of developing RA. Participants with 2-3 points were at “increased risk” — translating to a 25%-70% higher likelihood of developing the condition. Low-risk patients, with 0-1 points, had < 25% chance of developing RA.

Of the 182 ACPA–negative participants in the study, none were considered high risk, 66 (36%) were at increased risk, and 116 (64%) were at low risk.

Decreased Rates of RA Development

Of these ACPA–negative patients stratified as increased risk, 3 of 35 (9%) in the treatment group developed RA, compared with 9 of 31 (29%) in the placebo arm (hazard ratio [HR], 0.27; P = .034).

All 54 ACPA–positive patients enrolled in the study were classified as either increased risk or high risk, but the treatment showed no difference in the rate of RA development in this group, and more than half (56%) developed RA during 4 years of follow-up. However, van der Helm-van Mil noted that the 2-year data showed treatment improved the severity of subclinical inflammation and symptoms over time in these patients.

The 5-year data from the trial, including physical function and other measures of disease burden, will be analyzed in 2025, she said, and will reveal whether ACPA–negative patients treated with MTX had sustained improvements in these measures.

Additional studies are needed to validate these findings, van der Helm-van Mil said, but the results indicate that ACPA–positive and ACPA–negative patients “are different populations, and we should evaluate them separately.”

Future RA prevention studies should also risk stratify patients before enrollment so that patients at low risk of developing the disease are not included in the interventions. “You can’t expect a treatment effect if there is no risk for disease,” she added.

Is It Cost-Effective?

In a separate analysis, published in Annals of the Rheumatic Diseases, van der Helm-van Mil and colleagues sought to investigate the cost-effectiveness of the TREAT EARLIER intervention at 2 years of follow-up.

“There is an ongoing debate whether people with arthralgia at risk for RA should be treated with DMARDs [disease-modifying antirheumatic drugs]; however, the economic effects of an intervention in the arthralgia at risk phase are unknown.”

The analysis calculated healthcare productivity and work productivity costs from enrollment to 2 years of follow-up. To demonstrate effect, they also calculated change in quality-adjusted life years (QALYs).

Over the course of 2 years, estimated costs for the treatment arm were €4809 lower (−$5304) than the placebo arm per patient. Lower productivity costs accounted for 97% of this difference.

The treatment arm also resulted in a small improvement (+0.041) in QALYs, compared with placebo.

“These data provide the first evidence that first-line treatment aiming at secondary prevention in arthralgia at-risk for RA is cost-effective,” the authors wrote.

van der Helm-van Mil emphasized that this cost analysis used only 2-year follow-up data (rather than the newly published 4-year data) and did not differentiate ACPA–negative patients. Despite including a greater heterogeneity of patients, the intervention was still cost-effective. A future analysis that includes 5-year follow-up data and stratifies patients by ACPA status and excludes low-risk individuals could demonstrate more cost benefits to a temporary MTX regimen, she said.

Considering the costs of these preventive interventions is important, added Deane, who agreed that future analyses should examine cost-effectiveness in groups at high risk of developing RA. (Deane noted that he had reviewed this article for publication.) However, this analysis did not include the costs of screening patients before enrollment in the study.

“Additional factors that need to be considered are costs to find individuals who would meet the criteria for treatment,” he said, which would include getting an MRI to detect subclinical joint inflammation.

However, van der Helm-van Mil noted that both placebo and treatment groups received MRI scans, which would therefore not affect cost differences between the groups.

Future studies should also focus on longer-term outcomes, both Deane and van der Helm-van Mil agreed.

“Since RA is a chronic disease for which part of the patients require expensive biologicals, future cost-effectiveness analyses should also consider a lifetime horizon,” van der Helm-van Mil and colleagues wrote.

The TREAT EARLIER trial was funded by the Dutch Research Council and the Dutch Arthritis Society. The cost analysis study was funded by ZonMw and the Dutch Arthritis Society. Deane is a member of an American College of Rheumatology/European Alliance of Associations for Rheumatology task force for risk stratification in RA. He has received payments as a speaker for Werfen and Thermo Fisher Scientific and low-cost biomarker assays for research from Werfen. He has also received grant funding from Thermo Fisher Scientific, Gilead, and Boehringer Ingelheim. van der Helm-van Mil reported no disclosures.