'Biologic' Drug Fights Rheumatoid Arthritis

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'Biologic' Drug Fights Rheumatoid Arthritis

04.28.06, 12:00 AM ET

http://www.forbes.com/forbeslife/health/feeds/hscout/2006/04/28/hscout532394.htm\

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FRIDAY, April 28 (HealthDay News) -- A new " biologic " therapy with a unique

mechanism of action is proving effective in pushing painful rheumatoid

arthritis into remission over the long term, researchers report.

The drug, rituximab (brand name Rituxan), has already proven safe and

effective in treating non-Hodgkins lymphomas. But its ability to suppress

immune B-cells may make it a valuable new weapon against rheumatoid

arthritis as well.

" What rituximab does is give us another tool in our toolbox, particularly

for people who have failed other treatments, " said Dr. , chief

of rheumatology at Piedmont Hospital, in Atlanta, and national medical

advisor for the Arthritis Foundation.

was not involved in the study, which appears in the May issue of

Arthritis & Rheumatism.

Rheumatoid arthritis is a chronic inflammatory autoimmune disease, in which

the body's immune system attacks joint tissues, causing ongoing stiffness

and pain. The exact causes of the disease remain unclear, and treatment

effectiveness varies widely from patient to patient.

Many rheumatoid arthritis drugs are aimed at suppressing inflammatory

T-cells, but experts say that less than half of patients respond to these

therapies. Rituximab works on a wholly different mechanism, selectively

depleting another immune-system player, the B-cell.

" That's important, because one of the cardinal signs of rheumatoid arthritis

is what we call a 'positive rheumatoid factor,' " explained.

Rheumatoid factor is a kind of antibody long associated with severe

rheumatoid arthritis. While most people have a rheumatoid factor level of

well under 100, that number can soar in patients affected by the joint

disease. " I have a cousin, for instance, who the very first time I saw him

had a rheumatoid factor of 853, " said. " He had really diffuse disease

in every finger of his hands and every toe. "

The key to rituximab's effectiveness is that it depletes B-cells, the major

source of antibodies such as rheumatoid factor.

In the study, which was funded by drug makers Genentech, Biogen Idec and

Hoffman-La Roche, researchers in Europe and the United States followed the

six-month outcomes of 465 rheumatoid arthritis patients receiving either

rituximab by infusion or a placebo. All of the patients had shown little

response to other treatments.

The patients received two infusions two weeks apart of either 1,000 or 500

milligrams of rituximab, along with intravenous or oral steroids, or a

placebo. All participants also received a standard therapy, methotrexate.

Doctors checked the patients' progress every four weeks for a total of six

months.

The study " confirmed the efficacy of rituximab, " said lead researcher Dr.

Emery, professor of rheumatology and head of the Academic Unit of

Musculoskeletal Disease at Leeds Teaching Hospitals Trust in Leeds, England.

Based on a standard 28-joint assessment of swelling and tenderness, about 55

percent of these tough-to-treat patients achieved real disease improvement

after taking rituximab. That compared to just 28 percent of patients taking

methotrexate plus a placebo.

Furthermore, rituximab worked just as well at a lower dose as it did at the

higher dose. It also didn't seem to make a difference whether patients took

long-term steroids along with their rituximab or not.

" Steroids are given along with the medicine to help your body accept this

new protein that's coming into the body, " explained. They are also

given to help ease arthritic symptoms.

But the study found that patients taking rituximab didn't gain any added

benefit from steroids, beyond the dose given at the time of the infusion.

That's good news, Emery said, because " there are multiple side effects of

steroids, mainly due to cumulative long-term effects rather than short-term

actions. "

According to , these heartening results open a new window for patients

battling this crippling disease. " This is like everything else in

medicine -- if you have something that is very difficult to treat, you want

to have as many alternatives as possible, " he said.

likened the doctor's job to a mechanic's as he works on a car: The

more tools he has at hand, the better. " If you can have an extra wrench that

can help you get deep inside the engine, that's great. And what rituximab

can do is go deep inside the immune system and target this one specific nut

or bolt -- a specific type of inflammatory cell, the B-cell. "

He cautioned, however, that many rheumatologists may wait to use rituximab

until its true worth has been proven in a much larger, controlled clinical

trial.

That day may come soon, however. According to Emery, " longer trials are

planned to optimize the use of this very interesting drug. "