Treating RA: Single Drug vs. Combo

Nov. 19, 2007 -- Rheumatoid arthritis patients who do not respond to single-drug treatments often do better on a combination of drugs, a review of the research shows.

Researchers analyzed 23 studies comparing drugs that slow the progression of rheumatoid arthritis and published their findings online in the Annals of Internal Medicine.

Some of the studies compared one drug to another while others evaluated different combinations of drugs.

The analysis did not find any one drug to be better than another for single-drug treatment, but combining a synthetic disease-modifying anti-rheumatic drug (DMARD) like methotrexate with a biologic DMARD like Humira, Enbrel, or Remicade resulted in clearly superior response rates among patients previously taking single drugs. DMARDs slow the progression of rheumatoid arthritis.

"There is growing evidence that the combination of methotrexate plus [a biologic] works better than a single drug in many patients, and that was confirmed in this review," rheumatologist and study co-researcher Beth L. Jonas, MD, tells WebMD.

Rheumatoid Arthritis Now Manageable

More than 2 million Americans have rheumatoid arthritis, with three out of four cases occurring in women, the American College of Rheumatology reports.

Over the past 25 years, treatment advances have transformed the disease from a progressive, crippling condition to one that is largely manageable.

But there is confusion over whether the new biologics are better than the older synthetic DMARDs like methotrexate -- or which combination treatments offer the best results.

In an attempt to shed light on this issue, University of North Carolina researchers analyzed studies comparing one drug to another and drugs given in different combinations.

Their finding that no single drug was clearly better than another is encouraging for patients who take methotrexate and those who can't take the drug because they have liver disease, are pregnant, or have other contraindications, the researchers noted.

"It does look like methotrexate is similar to the newer biologics in the few studies that have compared them head to head, but this question is not settled," researcher Katrina Donahue, MD, MPH, tells WebMD. "There have been very few studies, but new ones are coming out daily."

The analysis did make it clear that the combination of methotrexate with an injected biologic resulted in better outcomes than single-drug treatment with methotrexate or a biologic alone.

Introduced in the late 1990s, biologic drugs help prevent joint and tissue damage by targeting inflammatory responses within the immune system.

The analysis did not indicate which combination treatment strategies worked best, but Donahue says ongoing research should help answer the question.

Future Treatment Strategy?

Rheumatologist Elinor Mody, MD, tells WebMD that the growing number of drugs that slow the progression of rheumatoid arthritis is good news for patients.

"The more therapies that are out there, the better," she says.

She adds that in the future rheumatoid arthritis may be treated like cancer, with a variety of drugs being used immediately after diagnosis in an attempt to put the disease into remission.

Mody directs the Women's Orthopedic and Joint Disease Center at Boston's Brigham and Women's Hospital.

"There is a lot of talk about this," she says. "The thinking is that if you achieve a remission early then you only have to retreat when necessary."