Immune System Drugs Help IBD

From Viagra Relative to Arthritis Medication, New Drugs Promise Gentler, Better Results

Medically Reviewed by Charlotte E. Grayson Mathis, MD on May 19, 2004

May 19, 2004 (New Orleans) -- New medicines -- ranging from a relative of Viagra to an arthritis drug -- target the haywire immune responses that underlie inflammatory bowel disease (IBD).

Inflammatory bowel disease is the umbrella term for a number of conditions that cause inflammation of the bowel. The two most common ones are ulcerative colitis and Crohn's disease. Both of these conditions occur when the immune system goes awry and attacks the lining of the colon. The disorders take a toll on their victims - affecting more than 1 million in the U.S. alone -- causing belly aches, diarrhea, and other symptoms that are often severe enough to interfere with daily activities, says James B. Lewis, MD, associate director of the inflammatory disease program at the University of Pennsylvania in Philadelphia.

"We're seeing many different approaches to treat this inflammation," says Stephen B. Hanauer, MD, professor of medicine and clinical pharmacology at the University of Chicago Pritzker School of Medicine. "For example, [corticosteroids] already used to treat IBD, are effective anti-inflammatory agents but they affect all tissues, causing many side effects."

Many of the new drugs, on the other hand, selectively target the defects associated with IBD -- an approach that promises better results with fewer side effects, he tells WebMD.

There were a number of new approaches discussed here at Digestive Disease Week, a major medical meeting of gastroenterologists.

Arthritis Medication Combats Crohn's, too

The rheumatoid arthritis drug Humira helped patients with moderate Crohn's disease to go into remission, Hanauer says.

A man-made biological substance called a monoclonal antibody, Humira works by blocking an inflammation-causing protein called tumor necrosis factor alpha, or TNF-alpha, that has been implicated in both rheumatoid arthritis and Crohn's disease.

In a study of nearly 300 patients who did not improve despite treatment with standard medications, 30% of those given higher doses of Humira were in remission by four weeks later, compared with only 12% on placebo, Hanauer reports.

Humira is an injectable drug and was extremely well tolerated, he says.

New Immune System Drug Antibody Prevents Crohn's Flare-Ups

In another new study, the drug Antegren helped prevent flare-ups associated with Crohn's disease in people who were in remission, reports Brian G. Feagan, MD, professor of medicine in the department of epidemiology and biostatistics at the University of Western Ontario in London.

The drug has already been shown to induce remission in Crohn's sufferers.

Antegren works by keeping immune system cells from leaving the bloodstream. In Crohn's patients, this appears to prevent the immune system attack on the gut that occurs with the disease, Feagan says. "If we can prevent that, white blood cells would stay in the circulation where they belong."

The researchers studied 339 adults with Crohn's disease who had improved or gone into remission after receiving three infusions of Antegren. The patients were randomly assigned to continue to receive Antegren for up to 12 additional monthly infusions, or to placebo.

Six months later, 44% of patients given Antegren were still in remission, compared with 26% on placebo, Feagan says. Also, 61% of those taking the drug continued to show an improvement in symptoms, compared with 29% on placebo.

People who took Antegren were no more likely to suffer side effects than those on placebo, he explains.

Viagra Relative Fights Ulcerative Colitis

The first of a totally new class of agents related to Viagra, the compound OPC-6535 appears to be safe and effective for the treatment of ulcerative colitis, Hanauer says.

In the study 186 people with active ulcerative colitis (diarrhea, rectal bleeding, abdominal pain, and/or other symptoms) were randomly assigned to receive one of two oral doses of the drug or a placebo for eight weeks. Many were also taking anti-inflammatory or other ulcerative colitis treatments like Rowasa or Pentasa.

The disease improved significantly in about half of the participants taking the active drug -- but the effect was greater in those taking the higher dose. Also, 20% of those taking the higher dose of OPC-6535 went into full remission from the disease, compared with fewer than 5% taking placebo, he says.

OPC-6535 attacks an enzyme that is present on immune cells in the brain and lung, inhibiting a number of white blood cell functions associated with inflammation, according to Hanauer.

Side effects observed in trials of OPC-3565 include headache, nausea, and dizziness.

A major advantage of the drug is that it is given in pill form, he notes. Many current therapies for ulcerative colitis are administered by injection or infusion.

Organ Transplant Drug Relieves Ulcerative Colitis

Other researchers report that Simulect, an injectable drug already used to prevent rejection of new organs in transplant patients, may also help people with ulcerative colitis.

"Currently, steroids are the best available treatment for ulcerative colitis, but 30% of patients simply don't respond," says Tom L. Creed, MD, PharmD, clinical research fellow at the Henry Wellcome Laboratories of the University of Bristol in the U.K. Others can't tolerate the drugs because of side effects, he says. There are few other options if steroids don't work except surgery to remove the colon (colectomy).

Simulect is an immune system suppressing drug. Therefore, it decreases the immune system response that causes ulcerative colitis symptoms.

In a study of 20 patients with moderately active ulcerative colitis disease (diarrhea, rectal bleeding, abdominal pain, unexplained weight loss, and possibly other symptoms) nearly two-thirds went into full remission, despite steroid therapy, Creed reports.

About 50% of those with severe disease achieved full remission.

Says Lewis, "All these drugs really change the way we look at inflammation. This is the future."

It's way too early to say which of the drugs will have the biggest impact, he says. When looking into his crystal ball, Lewis tells WebMD that combination therapy, with different drugs that target different parts of the immune system, is a likely approach for the future.

Show Sources

SOURCES: Digestive Disease Week 2004, New Orleans, May 16-20, 2004. James B. Lewis, MD, associate director, Inflammatory Disease Program, University of Pennsylvania, Philadelphia. Stephen B. Hanauer, MD, professor of medicine and clinical pharmacology, University of Chicago Pritzker School of Medicine. Brian G. Feagan, MD, professor of medicine, department of epidemiology and biostatistics, University of Western Ontario, London. Tom L. Creed, MD, PharmD, clinical research fellow, Henry Wellcome Laboratories, University of Bristol, United Kingdom.

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