Jan. 2, 2003 -- A promising experimental treatment for multiple sclerosis (MS) and Crohn's disease may be one step closer to reality for people who suffer from these mysterious and hard-to-treat diseases. New research on the drug called natalizumab shows it dramatically slows the progression of MS as well as prevents relapses of both MS and Crohn's disease.
The findings, published in the Jan. 2 issue of TheNew England Journal of Medicine, show the drug reduced the formation of new brain lesions in MS patients by about 90%. Researchers say that's significantly greater than the 50% to 80% reductions achieved with currently available beta-interferon treatments.
Another study in the same journal found that natalizumab -- which has been given the brand name Antegren but isn't yet approved by the FDA -- increased the rates of disease remission and improved the quality of life of people with Crohn's disease. The condition causes inflammation in the small intestine and leads to symptoms such as diarrhea and abdominal pain.
Both diseases are known as autoimmune diseases because they are caused by the immune system mistakenly attacking tissues in the body.
Although animal tests and smaller, human studies of the drug produced promising results in treating MS, until now the long-term effects of the drug were unknown.
In the first study, researchers gave the participants a low or high dose of the drug or a placebo. They found the number of new brain abnormalities was dramatically lower in the treatment groups compared with those given the placebo. An average of about 10 new lesions per patient were reported in the placebo group compared with only 0.7 and 1.1 new lesions in the two treatment groups.
In addition, about twice as many patients in the placebo groups had relapses of their disease compared with those who received natalizumab. Both treatment groups also reported an improvement in well-being while those who did not receive the drug said they felt slightly worse.
In the second study, a group of European researchers analyzed the effects of the drug in 248 people with moderate-to-severe Crohn's disease. The participants received a high or low dose of natalizumab or a placebo.
Researchers found the quality of life improved in all the patients who received the drug compared with those who did not, and both groups that got two doses of the drug had higher disease remission rates than those who received the placebo.
The researchers say the drug was well tolerated in patients involved in both studies.
In an editorial that accompanies the results, Ulrich H. von Andrian, MD, PhD, of Harvard Medical School, and colleagues write that the drug may lead to improvements in the treatment of other autoimmune disorders such as ulcerative colitis and rheumatoid arthritis as well as related conditions such as asthma and heart disease.
But the editorialists say that larger numbers of patients will need to be treated with natalizumab for longer periods of time to determine whether resistance to the drug may develop.