New MS Therapies Show Promise
But the side effects of one drug require much more research, researchers say
THURSDAY, Oct. 23, 2008 (HealthDay News) -- Two medications may prove to be advances in the treatment of multiple sclerosis, researchers say.
In one study, an experimental drug called oral fumarate (BG00012) substantially reduced symptoms in patients with relapsing-remitting multiple sclerosis, according to a phase II clinical trial by European and North American researchers.
And in a second trial, researchers found that the leukemia drug alemtuzumab (Campath) was about 70 percent more effective than another drug already widely used to treat MS. However, alemtuzumab also had significant side effects, including bleeding disorders, a greater risk of thyroid disease, and infections. This prompted experts to say that much more research is needed before alemtuzumab can be prescribed to treat multiple sclerosis.
Multiple sclerosis is a nervous system disease that affects the brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects nerve cells. This damage slows or blocks messages between the brain and the body, according to the U.S. National Library of Medicine.
Symptoms of the disease can include visual disturbances; muscle weakness; trouble with coordination and balance; sensations such as numbness, prickling, or "pins and needles;" and thinking and memory problems.
It's not known what causes multiple sclerosis. It may be an autoimmune disease, which happens when the body attacks itself. MS affects women more than men, and it often begins between the ages of 20 and 40. An estimated 400,000 Americans have the disease. Usually, the disease is mild, but some people lose the ability to write, speak or walk. There's no cure for MS, but medicines may slow it down and help control symptoms, according to the National Library of Medicine.
The 24-week study of BG00012 included 257 patients, ages 18 to 55, who were randomly assigned to receive either 120 milligrams of BG00012 once a day (64 patients), 120 milligrams three times a day (64 patients), 240 milligrams three times a day (64 patients), or a placebo (65 patients). The patients were assessed at weeks 12, 16, 20 and 24.
MRI brain scans showed that patients treated with 240 milligrams of BG00012 three times a day had 69 percent fewer new gadolinium enhancing (GdE) lesions -- a marker of MS-related inflammatory activity -- from week 12 to 24 than those who received the placebo. They also had fewer new or enlarging T2-hyperintense and T1-hypointense lesions at week 24.
The study also found that BG00012 reduced the annual relapse rate by 32 percent, but this finding wasn't statistically significant. Patients who received the drug were more likely than those in the placebo group to suffer adverse events such as abdominal pain and hot flush. Dose-related adverse events in patients taking the drug included headache, fatigue and feeling hot, the researchers said.
"Longer-term (phase III) studies of BG00012 in larger patient populations are underway to define its place in the future of relapsing-remitting multiple sclerosis treatment. If these studies show similar relapse rate reductions with BG00012, interferon beta, and glatiramer acetate, BG00012 could be a suitable initial treatment for relapsing-remitting multiple sclerosis," wrote Professor Ludwig Kappos, of University Hospital Basel, in Switzerland, and colleagues.
The study was published in the Oct. 24 issue of the The Lancet.
In an accompanying comment in the journal, Professor Per Soelberg Sorensen and Dr. Finn Sellebjerg of the Danish Multiple Sclerosis Research Center, noted that "BG00012 might have a favorable benefit-to-risk ratio profile compared with its oral competitors and the currently available first-line injectable drugs. However, we will have to await the results from the ongoing large phase III trials to establish the place of BG00012 and of other oral drugs in the treatment of relapsing-remitting multiple sclerosis."
The study of the leukemia drug alemtuzumab, which temporarily depletes white blood cells and is part of a class of drugs called monoclonal antibodies, included 334 patients. Patients were randomly assigned to get either alemtuzumab or interferon beta, a standard MS therapy, for three years.
Alemtuzumab reduced by 74 percent the risk of MS relapse, the researchers reported in the Oct. 23 issue of the New England Journal of Medicine.
"The ability of an MS drug to promote brain repair is unprecedented," Alasdair Coles, of Cambridge University in England, and one of the study's leaders, told the AFP news service. "We are witnessing a drug which, if given early enough, might effectively stop the advancement of the disease and also restore lost function by promoting repair of the damaged brain tissue."
However, in an accompanying journal editorial, Dr. Stephen L. Hauser, a neurologist at the University of California, San Francisco, said the "toxic effects associated with alemtuzumab considerably dampen any enthusiasm for its routine use in patients with multiple sclerosis until more is known about its long-term safety and sustained efficacy."
The U.S. National Institute of Neurological Disorders and Stroke has more about multiple sclerosis.