An experimental drug shows promise as an effective new approach for treating multiple sclerosis and the intestinal ailment Crohn's disease.
In preliminary tests, the new drug Antegren dramatically reduced the number of new brain lesions in patients with MS and cut the number of relapses in half. In Crohn's patients, it increased the rate of remission and improved the patients' quality of life.
Both were early studies, and researchers stressed that more definitive results will come from larger, longer studies that are now under way.
"At this stage, these are very promising results," said one of the MS researchers, Dr. David H. Miller of the Institute of Neurology in London. "One hopes that these will be confirmed ... and then one will have an additional effective treatment for people with MS."
The findings were reported in Thursday's New England Journal of Medicine. The studies were funded by the two companies developing the drug, Elan Corp. and Biogen Inc. Some of the researchers have received grants from the companies or worked as consultants for them.
There is no cure for MS or Crohn's and the causes are unknown. In both, the immune system goes awry, resulting in inflammation and damage to brain tissue in MS and to the intestinal wall in Crohn's disease.
MS patients can have loss of balance and coordination, blurry vision and fatigue. Crohn's causes chronic diarrhea, abdominal pain, fever and weight loss.
Current treatments include injections of interferon, which slows down the immune system, or anti-inflammatory drugs, including steroids, which ease the swelling. Some of the drugs have serious side effects and they don't work for all patients, researchers said.
Antegren, also called natalizumab, is the first in a new class of medicines that uses a novel approach to prevent inflammation. It attaches to the immune cells and stops them from leaving the bloodstream and reaching the areas of inflammation in MS and Crohn's.
Dr. Lars Ekman, president of research and development at Elan, said the companies expect to seek approval for the drug at the end of 2003 in the United States and Europe. Depending on the regulatory process, the drug could be available as early as the end of 2004, he said.
In the MS study, 213 patients in the United States, Canada and the United Kingdom were given six monthly infusions of one of two Antegren doses or a dummy drug. Patients who received the dummy drug had about 10 new brain lesions, compared to about one new lesion in those getting Antegren, a reduction of about 90 percent.
The frequency of relapses was cut in half in the Antegren groups, to 19 percent from 38 percent in the comparison group.
The 248 patients in the Crohn's study in Europe received two infusions a month apart of either of two Antegren doses, a dummy drug or a combination of Antegren and the dummy drug. A scoring system measured their response over 12 weeks.
Overall, the patients who received only Antegren had higher remission rates and response rates. The highest remission rate was 44 percent at six weeks in the low dose Antegren group, compared with 27 percent in the dummy drug group.
In both studies, there were few serious side effects and there was no difference in side effects between the treatment groups.
One of the Crohn's researchers, Dr. Subrata Ghosh of Imperial College London, said he was particularly encouraged because the drug improved the quality of patient's lives.
"The wider the choice of therapy available, the better for the patients. And certainly as clinicians, we welcome that," said Ghosh.
Patricia O'Looney, director of biomedical research programs for the National Multiple Sclerosis Society, said the future for MS treatment may be drug combinations. One of the ongoing studies is testing Antegren with a standard interferon drug.
"It's promising new results for a new approach to treating people with MS, but we're not at the end of the story yet,' said O'Looney.
On the Net:
New England Journal: http://www.nejm.org
National Multiple Sclerosis Society: http://www.nmss.org
National Institutes of Health: http://www.niddk.nih.gov/health/digest/pubs/crohns/crohns.htm