New Drug Helps Tough-to-Treat Rheumatoid Arthritis

Abatacept doubles chance of significant improvement, study finds

WEDNESDAY, Sept. 14, 2005 (HealthDay News) -- People with rheumatoid arthritis that doesn't respond to any of the currently available treatments may soon have a new therapeutic option.

A new medication called abatacept (brand name, Orencia), more than doubled the odds that someone with difficult-to-treat rheumatoid arthritis had at least a 20 percent improvement in symptoms, according to a new study.

"Rheumatoid arthritis patients should be optimistic because there's now another option that works well, even where other drugs haven't," said Dr. Mark Genovese, an associate professor of medicine and the associate division chief in immunology and rheumatology at Stanford University.

Genovese is the lead author of the study published in the Sept. 15 issue of the New England Journal of Medicine. He is also a paid consultant for Bristol-Myers Squibb, the manufacturer of the drug.

More than 2 million Americans have rheumatoid arthritis, according to the Arthritis Foundation. It is an autoimmune disease, which means the body's immune system mistakenly attacks itself. The disease is characterized by red, swollen, stiff, painful joints. As the disease progresses, loss of movement and function in the affected joints can occur.

Current treatment options include over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) and other pain relievers; oral steroids; anti-rheumatic drugs, such as methotrexate; and biologic response modifiers, such as etanercept and infliximab, according to the Arthritis Foundation.

While many people experience relief by using one or a combination of these therapies, they don't work for everyone. And, some of the medications work initially, and then stop working in certain people, said Dr. Martin Pevzner, chairman of rheumatology at Beaumont Hospital in Royal Oak, Mich.

Abatacept may be an option for people who don't respond well to other therapies, he said.

The new study compared the use of abatacept to a placebo. Approximately 220 patients received abatacept and 99 received a placebo for the entire six-month study. Study volunteers in both groups were also given an anti-rheumatic drug as well.

According to Genovese, abatacept works by blocking a signal that fully activates the immune system's T-cells. Because the drug modifies the response of the immune system, the risk of infection is potentially increased.

During the study, the participants were given questionnaires to assess their health, and their physical function was tested.

Slightly more than 50 percent of those taking abatacept experienced a 20 percent improvement in their rheumatoid arthritis signs and symptoms, while just 19.5 percent of those on a placebo experienced similar improvement. And while 20.3 percent in the abatacept group saw a 50 percent improvement, less than 4 percent of those in the placebo group did.

At the end of the study, after six months of treatment with abatacept, 47.3 percent of participants had clinically significant improvements in their physical function, compared to just 23.3 percent of the placebo group.

There was no significant difference in the rate of infection between each group. There was a slight difference in the rate of side effects and adverse reactions, with the abatacept group reporting slightly more problems.

"This study is significant in the sense that you're dealing with patients who have failed on multiple other drugs," said Pevzner, who added that this study should give such patients some hope for the future. "There are more novel things coming to treat this disease. More drugs are coming and patients are functioning better."

Genovese said abatacept hasn't been approved by the U.S. Food and Drug Administration, but an FDA advisory committee met earlier this month and recommended approval of the drug. He said the FDA's decision is expected sometime around the end of the year.

More information

The Arthritis Foundation has more information on rheumatoid arthritis.

SOURCES: Mark Genovese, M.D., associate professor of medicine, and associate division chief, immunology and rheumatology, Stanford University School of Medicine, Stanford, Calif.; Martin Pevzner, M.D., chairman, rheumatology, Beaumont Hospital, Royal Oak, Mich.; Sept. 15, 2005, New England Journal of Medicine
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