An international team of researchers has found that adding a humanized monoclonal antibody called daclizumab to standard multiple sclerosis treatment reduces the number of new or enlarged brain lesions in patients with relapsing multiple sclerosis. This new study was published online February 16, 2010 and in the March edition of The Lancet Neurology

Multiple sclerosis is a debilitating disease in which the body’s immune system attacks the fatty substance that surrounds and protects the nerve fibers in the brain and spinal cord. The resulting damage interferes with the transmission of nerve signals between the brain and spinal cord and other parts of the body, producing a variety of symptoms including problems with balance, coordination, vision, and even mental function. Approximately 85 percent of people are initially diagnosed with relapsing multiple sclerosis, in which clearly-defined attacks of worsening neurologic function are followed by partial or complete recovery periods during which no disease progression occurs.

The researchers performed a randomized, double-blind, placebo-controlled study at 51 centers in the U.S., Canada, Germany, Italy, and Spain. They recruited 230 patients with relapsing multiple sclerosis who were taking interferon beta and randomly assigned them to receive add-on treatment with high-dose daclizumab, low-dose daclizumab, or placebo. The primary objective of the study was to assess whether daclizumab affected multiple sclerosis disease activity by measuring the total number of new or enlarged lesions in the brain during 24 weeks of treatment.

In addition to finding that add-on treatment with high-dose daclizumab resulted in a significantly lower number of new or enlarged multiple sclerosis lesions, the researchers found that patients treated with either high- or low-dose daclizumab had a seven to eight times higher number of immune cells called CD56^bright natural killer cells (NK Cells). Previous research has shown that untreated multiple sclerosis patients have lower numbers of these NK cells than healthy individuals.

Further research is needed to clarify whether the risk-benefit of daclizumab is better when the drug is used alone or in combination with interferon beta for treatment of multiple sclerosis, as well as to determine the optimum dose and length of treatment needed to see the full therapeutic effects of the drug.

Source:

The Lancet Neurology, published online first 16 February 2010.