A drug that has been used to treat advanced rheumatoid arthritis can also slow the progression of the disease in its early stages, according to a new study published in the New England Journal of Medicine (NEJM).

"We chose patients with early disease who are likely to have a lot of destruction, and when they received Enbrel, they responded very nicely to it, just as patients with advanced disease in reducing signs and symptoms," says the study's lead author, Joan Bathon, MD, associate professor of medicine at Johns Hopkins Medical Institutions in Baltimore, Maryland. "But more importantly, it was very impressive in slowing or even halting damage [as] assessed by the X-rays."

Researchers compared the effects of Enbrel (etanercept) and methotrexate on 632 patients in the earliest stages of rheumatoid arthritis. Participants who were given methotrexate took it by mouth once a week. Those who were given Enbrel took it by self-injection two times a week.

Methotrexate is an anti-cancer drug that is now considered a standard treatment for rheumatoid arthritis in the US. Enbrel belongs to a new class of high-tech drugs that fend off the tumor necrosis factor (TNF), which is known to trigger much of the joint inflammation and pain that comes with rheumatoid arthritis.

After a year of treatment on one of the drugs, participants underwent an X-ray evaluation, which measured bone and cartilage erosion due to joint inflammation.

The study found both drugs worked to stop the increase of bone erosion in most participants. Investigators say the disease stopped progressing in 72% of Enbrel patients, compared to 60% of methotrexate patients.

Enbrel also seemed to do better than methotrexate in terms of side effects, suggest researchers. "The short-term side effects that we could assess during a 12-month period were less with Enbrel than with methotrexate," says Bathon. "The only really statistically significant side effect of Enbrel was what we call 'injection site reactions.' These are areas of swelling, itching and discomfort right around the injection site."

Side effects of methotrexate include nausea and liver irritation. Bathon says these adverse events were serious enough to make patients stop taking the drug. She notes that methotrexate patients are twice as likely to halt treatment than Enbrel patients.

In an editorial also published in NEJM, John Klippel, MD, of the Arthritis Foundation in Atlanta, Georgia, wrote that "it seems reasonable to argue, on the basis of this evidence, that TNF inhibitors should be used as early as possible in all patients who have documented rheumatoid arthritis."

Klippel adds, however, that the lack of long-term studies on TNF inhibitors and the high cost of the medication are barriers to using etanercept drugs. Enbrel patients reportedly spend $10,000 to $12,000 per year.

According to the Arthritis Foundation, rheumatoid arthritis affects 2.1 million Americans, mostly women per year. Most people get the disease in middle age, but it often occurs in the 20s and 30s.

The FDA recently approved Enbrel for treatment of rheumatoid arthritis at the earliest signs of the disease. Officials based their decision on Bathon's study. Previous to the FDA's nod, only patients with the advanced form of the disease were indicated to take the drug.

(From CBSHealthWatch)