Longer Term Results of Etanercept Therapy in Early RA

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Hi everyone,

An interesting article from www.veritasmedicine.com:

The introduction of anti-tumor necrosis factor (anti-TNF) drugs in

1999 provided a new approach to the treatment of rheumatoid arthritis

(RA). Reducing the body's level of TNF--an inflammatory molecule

produced in response to a variety of stresses--was found to be an

effective way to reduce the inflammation associated with RA. One of

these drugs, etanercept (Enbrel™), consists of the receptor for TNF

fused with another protein called immunoglobulin Fc. This receptor

part of the drug acts as a sponge, soaking up TNF in the blood. The

immunoglobulin Fc part of etanercept acts a signal to the body to

remove it from the blood stream. Etanercept was quickly found to be

very effective at reducing TNF levels, and at improving symptoms in

the average patient with RA.

Etanercept has now been tested in a select type of RA patients--those

with recent onset RA. The initial findings from this study, called

the early RA (ERA) trial1, demonstrated that etanercept is an

effective treatment in newly diagnosed patients over the course of

one year. The longterm effectiveness remained to be determined. Now,

however, 24 month results for the ERA trial have been reported

recently in the journal Arthritis & Rheumatism2.

The ERA trial was designed to assess the usefulness and safety of

etanercept in patients with RA of recent onset. Because effective

therapies for the treatment of RA are already available, researchers

could not ethically compare etanercept to treatment with placebo-- a

sugar pill. Instead, since methotrexate is currently the most widely

prescribed disease modifying drug (DMARD) used in RA, it has become

the standard to which other treatments are often measured. The ERA

trial therefore compared etanercept with methotrexate therapy in

patients who had experienced symptoms of RA for less than three

years.

The patients selected for this trial were experiencing significant

symptoms of inflammation at the beginning of the trial. In addition,

the trial intentionally included patients who were at high risk for

progression of joint destruction evident by x-ray erosions. 632

patients were originally enrolled in this study and 512 elected to

continue in the second year of the study. Clinically, both

methotrexate and etanercept continued to demonstrate benefit in the

second year of study. Although some patients in both groups showed

ongoing joint destruction, patients treated with etanercept had less

destruction. Of note, a significant percentage of patients in both

groups showed no progression of joint destruction--65% treated with

methotrexate and 79% treated with etanercept. More etanercept-treated

patients also showed improvement in their ability to perform normal

daily functions.

The safety profile of etanercept during the second year of treatment

showed no unusual side effects. Temporary painful reactions at the

injection site remained the most common adverse reaction with

etanercept. There was no increase in infections and no increase in

cancer incidence noted for etanercept therapy. At the end of the

study period, 74% of patients remained on etanercept while 59%

remained on methotrexate.

Overall, these results demonstrate the continued effectiveness of

therapy with either methotrexate or etanercept. Both medications

lead to improvements in inflammatory scores and functional status

relative to baseline at the start of the study. In addition, a

significant number of patients on either medication showed no

progression of joint destruction. While other studies have suggested

that anti-TNF drugs can increase one's risk of infection, there was

no suggestion of increased infection in this study. Overall, these

results provide further evidence for patients and physicians

considering treatment options for RA.

References:

1Bathon, J.M. et. al. " A comparison of etanercept and methotrexate

in patients with early rheumatoid arthritis. " 2000. New England

Journal of Medicine 343:1586-1593.

2Genovese, M.C. et. al. " Etanercept versus methotrexate in patients

with early rheumatoid arthritis. " 2002. Arthritis & Rheumatism

46:1443-1450.