Longer Term Results of Etanercept Therapy in Early RA

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Longer Term Results of Etanercept Therapy in Early RA

08/02/2002

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.  ³A comparison of etanercept and methotrexate in

patients with early rheumatoid arthritis.²  2000.  New England Journal of

Medicine 343:1586-1593.

 

2Genovese, M.C. et. al.  ³Etanercept versus methotrexate in patients with

early rheumatoid arthritis.²  2002.  Arthritis & Rheumatism 46:1443-1450.