(October 22, 2008 - Insidermedicine) A biological drug called alemtuzumab may treat multiple sclerosis (MS) more effectively than standard treatment with interferon beta 1a, but it may also result in a higher risk of serious side effects, according to research in the New England Journal of Medicine.

Here are some facts about MS:

•    It is a chronic disease that attacks the central nervous system, which is made up of the brain, spinal cord, and optic nerves.

•    Symptoms of MS can range anywhere from mild numbness in the limbs to paralysis and loss of vision.

•    Some people experience a slow worsening in their symptoms, while others may have flare ups followed by some relief from their symptoms.

Researchers for the CAMMS223 Trial randomly assigned over 300 patients diagnosed with MS within the previous three years to treatment with interferon beta 1a or alemtuzumab. The initial plan was to treat the patients for three years, but those taking alemtuzumab stopped their treatment early due to the development of severe immune-system related side effects in three patients, including one who died.

Those treated with alemtuzumab had less disability and fewer relapses of MS. Brain scanning also revealed that alemtuzumab-treated patients developed fewer of the brain lesions typical of MS and experienced an increase in brain volume, while those taking interferon beta 1a actually experienced some brain shrinkage. Still, serious side effects, including immune system dysfunction and infections, were more common among those taking alemtuzumab.

Today’s research demonstrates that alemtuzumab may be more effective for a common type of early MS than interferon beta 1a, but the tradeoff appears to be an increased risk for serious side effects.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.