New Therapy for Relapsing MS Shows Promise

A team of international researchers have recently found a new possible therapy that promises to help reduce the number of new or enlarged brain lesions in people with relapsing multiple sclerosis. The researchers have found that adding a humanized monoclonal antibody called daclizumab to available standard treatment enables the substantial reduction of new brain lesions in patients suffering from relapsing MS.

Multiple sclerosis is an autoimmune disease characterized by the body’s hyperactive immune system attacking the myelin, a fatty substance that protects the nerve fibers in the brain and the spinal cord. Considerable damage to the myelin covering the nerve fibers interferes with its ability to effectively transmit nerve signals between the central nervous system and the other parts of the body. This interference results into a number of symptoms which may include, vision, coordination and balance problems as well as considerable aspects of mental function. A majority of people are usually diagnosed with relapsing MS, a type of MS where patients experience a period of attacks displaying a worsening neurologic function that is usually followed by a period of partial or complete recovery where no signs of disease progression occurs.

Monoclonal antibodies such as daclizumab are immune system proteins that binds itself to specific target cells which then triggers the immune system to attack those cells. Daclizumab is a type of monoclonal antibody specific for CD25, a protein that is expressed in active T cells. The binding of daclizumab with CD25 results in the selective inhibition of these activated T cells.

According to John W. Rose, professor of neurology at the University of Utah School of Medicine, Neurovirology Research Laboratory, Veterans Affairs Salt Lake City Health Care System and the University of Utah and the study author, "Previous research has shown that treatment with daclizumab reduced multiple sclerosis disease activity. Our work in the CHOICE trial shows that daclizumab significantly reduces MS lesion formation in people with active relapsing disease."

Rose and his fellow researchers conducted a randomized, double-blind, placebo controlled study that covered 51 centers in the US, Canada, Germany, Italy and Spain. 230 patients with relapsing MS who were taking interferon beta to become part of the study. The participants were randomly assigned to receive additional treatment with either a high-dose daclizumab, low-dose daclizumab or a placebo. The main objective of the study is to assess whether dacluzimab may have any effects on MS disease activity by measuring the total number of new or enlarged brain lesions during the 24 weeks of treatment.

The study showed that those who took the high-dose daclizumab as an add-on treatment had a significantly lower number of new or enlarged brain lesions. Aside from that, those who took high-dose and low-dose daclizumab as add-on treatments also showed having seven to eight times higher number of immune cells called CD56bright NK cells or natural killer cells. Previous studies have shown that untreated MS patients also have lower numbers of these NK cells as compared to healthy individuals.

"This study provides confirmatory data that daclizumab treatment causes an expansion of CD56bright natural killer cells and adds support to the theory that this expansion might mediate some of the effects of daclizumab on reducing multiple sclerosis lesion activity," says Prof. Rose. Further studies are required to determine whether dacluzimab use is more favorable when used alone or together with other existing treatments such as interferon beta.

Source: University of Utah Health Sciences. "Promising Therapy for Relapsing Multiple Sclerosis." ScienceDaily 18 February 2010. 3 March 2010