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CHICAGO -- Monotherapy with etanercept (Enbrel) can keep some rheumatoid arthritis (RA) patients in long-term remission, researchers said here.

Combination therapy with etanercept and methotrexate is considered standard of care for RA, said Roy Fleischmann, MD, from the University of Texas Southwestern Medical School in Dallas. But in 34 of 61 patients in this study who opted to remain on etanercept monotherapy, disease remission -- as measured by the Disease Activity Scale (DAS28) -- was maintained after nine years of treatment, he reported at American College of Rheumatology annual meeting.

The Early Rheumatoid Arthritis (ERA) study included about 200 patients, 114 of whom were treated with etanercept monotherapy. Nine years later, researchers were able to evaluate the status of 61 of these patients who remained on monotherapy.

Patients were randomized to receive etanercept (10 mg or 25 mg) twice weekly or methotrexate. After one year, patients continued on treatment unblinded. The current analysis examined patients who received and continued on etanercept 25 mg twice weekly.

In addition to DAS28, other outcome measures were Simple Disease Activity Index (SDAI) scores and Health Assessment Questionnaire Disability Index (HAQ-DI) scores.

According to the results, low disease activity was achieved by one year in 64.9% of patients by DAS28 and in 62.5% of patients by SDAI. Remission was achieved in 45.6% of the patients based on DAS28 and in 14.3% based on SDAI.

At year nine, 67.3% had low disease activity by DAS28 and 61.8% had the same by SDAI, with 54.5% and 32.7% in remission, respectively. The authors reported that SDAI scores varied widely from visit to visit for individual patients. Still, most patients in SDAI remission at year nine had been in SDAI low disease activity or better at each time point starting from year one or two.

HAQ-DI scores improved from mean of 1.41 (standard deviation 0.70) at baseline to 0.65 (SD 0.74) at six months. HAQ-DI scores had improved to scores associated with the general population (score ≤ 0.5) in 54.1% of patients at year one and in 55.7% of patients at year nine.

"What would you do if you could get a person early into remission on etanercept and methotrexate and they are really doing great?" Fleischmann said. "What this study tells you is that one of the things you can think about is getting rid of the methotrexate. What we see is that about a quarter of these patients do great," he said. "They are still in DAS28 remission on monotherapy, nine years out."

He noted that many patients discontinue treatment with methotrexate because of adverse side effects with rates of methotrexate discontinuation due to toxicity range from 5% to 35% in prospective and retrospective studies.

The finding from ERA study are not necessarily unique, but still offer valuable clinical information, said Arthur Brawer, MD, from Monmouth Medical Center in Long Branch, N.J. "I have patients like this who do well long term on etanercept monotherapy," he said.

However, Fleischmann noted that one reason clinicians prefer combination therapy is because about 6% of etanercept RA patients taking etanercept develop antibodies to the biologic agent, which can negatively impact its effectiveness. Methotrexate has been shown to decrease that risk of developing antibodies.

Limitations included a lack of generalizability of the findings because the patients were not randomized to etanercept monotherapy but self-selected to remain on the single drug. But he pointed out that there were no discernible baseline characteristics (age, sex, race, rheumatoid factor status, disease severity) between the 61 patients for whom nine-year data on etanercept monotherapy was available and the 114 patients originally placed on etanercept monotherapy.