Cancer Drug Rituxan Cuts MS Flare-ups
Studies Show Multiple Sclerosis Patients Taking Rituxan Have Fewer Brain Lesions
May 1, 2007 (Boston) -- A drug that is already used to treat cancer and rheumatoid arthritis cut by more than half the chance that people with multiple sclerosis would have their symptoms flare up over a six-month period, researchers report.
In two early studies, people taking the drug, Rituxan, also had fewer areas of damage, or lesions, in their brain than those on placebo.
"We believe that if we can prevent these lesions, we can modify the course of this disease," says researcher Stephen Hauser, MD, chairman of neurology at the University of California, San Francisco, and president of the American Neurological Association.
If the research pans out, "this would be a very attractive and probably blockbuster therapy," he tells WebMD.
The research was presented at the American Academy of Neurology's 59th Annual Meeting.
How Rituxan Works
The exact cause of multiple sclerosis (MS) is unknown. But the disease is thought to be triggered by a malfunction in the immune system that prompts immune cells to attack the brain and/or spinal cord. The most common form of multiple sclerosis is a relapsing-remitting form in which relapses or "attacks" of worsening neurologic function appear, and then disappear, for months or years at a time.
Like many other drugs for MS, Rituxan targets the immune system to help calm the inflammation that scars nerves, leading to disease progression. But Rituxan homes in on the immune system in a brand new way, Hauser says.
The drug works by targeting cells in the immune system called B cells, which make antibodies that contribute to the disease process. B cells also secrete chemicals that can encourage inflammation, he says.
Though never compared head-to-head, the early research hints that the drug is twice as effective as drugs such as interferon that are now used to treat multiple sclerosis, he says.
Also, it's more convenient, requiring only two infusions every six months or so instead of the daily to weekly injections associated with current therapies, Hauser says.
Fewer Flare-ups in People on Rituxan
Both of the new studies involved people with the relapsing-remitting form of MS. In the first study, 69 people were given two one-hour infusions of Rituxan two weeks apart and 35 were given a placebo.