Multiple Sclerosis: Advances in Research and Treatment
MS: Drug Treatment Options Grow
Eight medications are approved by the FDA to reduce the frequency of relapses and possibly slow the progression of MS. These drugs are called disease-modifying therapies. So far, most MS disease-modifying drugs must be injected or administered intravenously. The newest drug, Gilenya (fingolimod), approved by the FDA in 2010, is the first disease-modifying MS drug that can be taken orally.
Fingolimod has been shown in studies to reduce the relapse rate of MS by up to 54% compared to placebo. However, it has serious side effects, with possible heart, lung, and eye toxicity and increased risk of infection. Patients must be closely monitored, and regular eye exams are advised.
Other new drugs for multiple sclerosis that can be taken orally are in clinical trials. If approved, they may offer a welcome end to injections for some patients.
Approval of these drugs will be just the beginning, predicts Cohen, who has been a consultant and researcher for Novartis, which makes fingolimod, as well as for other pharmaceutical companies. He speculates that eight or 10 new medications for MS will become available over the next three to five years, as basic research comes to fruition and scientists discover medicines approved for other diseases that also may help MS patients.
MS: Repairing the Damage
Restoring nervous system function is a hot focus in MS research.
Traditionally, experts believed that once myelin was destroyed, ''that was it," says O'Looney. "Now we know there is the potential for remyelination."
A major research goal is to figure out how to replace the cells that make myelin, which are lost in MS patients. Researchers have had some success using human embryonic stem cells to generate myelin-producing cells. They are studying the effectiveness of adult stem cells. Growth factors (substances that affect the growth of a cell) are also being studied for their ability to repair myelin-producing cells.
The focus has also moved beyond just the myelin to the nerve fibers or axons. ''We know now there is a dynamic interaction between the myelin and the axons," says Peter Calabresi, MD, a professor of neurology at Johns Hopkins University and a leader in this nervous system repair effort.
''The myelin tells the axon (nerve fibers) to be more or less functioning,'' Calabresi says. A better understanding of the interaction, he says, will hopefully help scientists figure out how to rescue the axons and restore the myelin. Calabresi has received grants and consulting fees from Biogen Idec, which makes MS drugs.