New Therapy for Crohn's, MS Has Promise
Natalizumab helps against autoimmune disorders
THURSDAY, Jan. 2, 2003 (HealthDayNews) -- A genetically engineered molecule produced promising results in studies of its use against multiple sclerosis and Crohn's disease, two conditions in which the body mistakenly attacks its own tissue.
Two new studies are just gate-openers to much larger trials, well under way, designed to gain approval for widespread use of the treatment, says Dr. Burt Adelman, executive vice president for research and development for Biogen, the biotechnology company that hopes to market the drug.
"We expect interim results for multiple sclerosis by the end of 2003 or early 2004, and by early 2004 we could be applying for approval against Crohn's disease," Adelman says.
The molecule, called natalizumab (brand name Antegren), works by blocking the activity of certain cells of the immune system, which normally protect the body by destroying invading viruses and bacteria, but somehow turn their destructive power against normal cells.
In multiple sclerosis, those are nerve cells. In Crohn's disease, they are cells of the gastrointestinal tract. In each case, there are periodic bouts of destructive inflammation that can cause chronic abscesses, rectal bleeding and other symptoms in Crohn's disease and symptoms ranging from numbness to paralysis in the case of multiple sclerosis.
Natalizumab, given by injection, binds to the surface of the immune T cells that cause the damage, preventing them from reaching the target tissue.
In the multiple sclerosis trial, 213 patients with a severe form of the disease were given either monthly injections of natalizumab or a placebo, an inactive substance, by physicians at the Institute of Neurology in London. There was a marked reduction in the number of new nerve cell lesions in the natalizumab group, and no reduction in the placebo group, says a report in today's issue of the New England Journal of Medicine. Patients getting natalizumab reported an improvement in overall well-being, while the placebo patients reported a worsening.
The Crohn's disease trial, involving 248 people, was done at Imperial College in London, again with some patients getting different doses of the drug and others getting placebo. "Both groups that received two infusions of natalizumab had higher remission rates than the placebo group at multiple time points," the journal report says. "Natalizumab also produced also produced a significant improvement in response rates."
Side effects of the treatment in both studies generally were minor -- headaches, weakness, urinary tract infections, and back pain.
Dr. Patricia O'Looney, medical director of the National Multiple Sclerosis Society, has a controlled enthusiasm about the study."The exciting news is that this is a new type of therapy and if these results hold true, there could be a new approach to treating multiple sclerosis," she says.
But, she adds, "It is too premature to say. This was a small study of just six months. Multiple sclerosis is unpredictable and highly variable, which makes it difficult to predict any outcome. Much larger studies need to be done."
Those trials have begun, Adelman says, and Biogen is hopeful about their results.
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