New Drug Therapies Look Promising for Bowel Diseases

Long-term and biologic treatments are emerging candidates, researchers say

TUESDAY, May 23, 2006 (HealthDay News) -- For bowel disorders such as Crohn's disease and irritable bowel syndrome, long-term treatments with new compounds look promising, researchers report.

And, for those with moderate to severe Crohn's disease, which often does not respond to conventional treatment, the new biologic therapies, which target the specific cause of the inflammation causing the disease instead of suppressing the entire immune system as traditional medications do, also look good, experts said.

The experts shared their assessments Monday at the annual Digestive Disease Week meeting, in Los Angeles.

More than one million people in the United States have inflammatory bowel diseases, said Dr. Maria Abreu, director of the Inflammatory Bowel Disease Center at Mount Sinai Medical Center in New York City, who chaired the panel.

While all the treatments are "tremendously important," adalimumab (Humira), a medicine already approved for the treatment of rheumatoid arthritis and psoriatic arthritis, may be a "front runner" for bowel disease patients, she said. Not all the treatments discussed are yet on the market.

Inflammatory Bowel Disease (IBD) includes the diseases ulcerative colitis, an inflammation in the lining of the rectum and colon causing frequent emptying and diarrhea, as well as Crohn's disease, an inflammation of the gastrointestinal tract that most often affects the lower part of the small intestine. Swelling leads to pain and diarrhea. Irritable Bowel Syndrome is mainly a problem that affects the large intestine, leading to cramping, bloating, diarrhea and constipation.

In patients with arthritis as well as Crohn's disease, some similar inflammatory proteins are increased. This lead researchers to test arthritis medicines for these gastrointestinal tract diseases.

In Monday's session, researchers reported results of a series of studies.

Adalimumab (Humira) provided remission from Crohn's disease in patients with moderate to severe disease, said Dr. Jean-Frederic Colombel, the lead author of the study and a researcher at Centre Hospitalier Universitaire de Lille, in France. In the study, which included 854 patients and continued for 56 weeks, 46 percent of those on the drug achieved remission, compared to just 17 percent on placebo.

Natalizumab (Tysabri), a drug approved for multiple sclerosis, was voluntarily taken off the market last year, when it was potentially linked to deadly brain infections called progressive multifocal leukoencephalopathy (PML). But it's expected back on the market, after the manufacturer submitted more data to the U.S. Food and Drug Administration to prove safety, and an FDA advisory panel recommended reintroduction of the drug.

Dr. Stephan Targan is director of the inflammatory bowel disease center at Cedars-Sinai Medical Center in Los Angeles, and the lead author of a study of Tysabri treatment for more than 500 Crohn's disease patients. He reported that a higher proportion of patients in the Tysabri group responded to the therapy at weeks eight and 12 than those in a placebo group -- 48 percent vs. 32 percent, respectively. More than 25 percent of the Tysabri group had remission by weeks eight and 12, compared to 16 percent of those taking a placebo. The drug dampens the immune response that causes the inflammation characteristic of Crohn's disease.

Another study of Tysabri, which included 2,248 patients with either Crohn's disease, multiple sclerosis or rheumatoid arthritis, found the risk of developing the PML brain infection was very low, according to Dr. William Sandborn of the Mayo Clinic, who led the study. Before the voluntary recall of the drug, three patients were identified with the infection, and four more infections were initially reported in post-marketing reviews. Sandborn's analysis, in which his team checked spinal fluid and blood, found no additional cases among the patients studied, and the four post-marketing cases did not have the infection after all.

Another biologic treatment, which is called certolizumab pegol and is in phase III clinical trials, helped those with moderate to severe Crohn's disease. The 659 patients were assigned to the drug or placebo; at week four, 20 percent of those on the drug achieved remission and response, compared to 10 percent on a placebo.

Lubiprostone (Amitiza), approved in January 2006 by the FDA for chronic constipation, also helped patients with IBS, said Dr. John F. Johanson, lead study author and a researcher with Rockford Gastroenterology Associates, in Illinois. About 50 patients were assigned to each of four groups -- either a placebo or one of three drug doses. All those on the drug showed improvement, compared to those on a placebo, and those who took the highest dose improved the most.

Teduglutide is a naturally occurring hormone under study that governs the growth and maintenance of cells lining the gastrointestinal tract. Dr. Alan Buchman, a researcher at Northwestern University's Feinberg School of Medicine, led a study in which three different doses of the drug or a placebo were given to 100 people with Crohn's disease. Half of the drug-treated patients responded after two weeks, and more than one-third also achieved remission then, too. After eight weeks, 61 percent of the treatment group responded, and 56 percent also had remission.

More information

To learn more about bowel disorders, visit the American College of Gastroenterology.

SOURCES: Maria Abreu, M.D., director, Inflammatory Bowel Disease Center, and associate professor of medicine, Mount Sinai Medical Center, New York City; Jean-Frederic Colombel, M.D., researcher, Centre Hospitalier Universitaire de Lille, France; Stephan Targan, M.D., director,inflammatory bowel disease center, Cedars-Sinai Medical Center, Los Angeles; William Sandborn, M.D., Mayo Clinic, Rochester, Minn.; John F. Johanson, M.D., researcher, Rockford Gastroenterology Associates, Rockford, Ill.; May 22, 2006, presentations, Digestive Disease Week meeting, Los Angeles
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