MS: Drug Treatment Options Grow continued...
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.
Identifying and Treating Disparate Causes of MS
In the past few years, vitamin D has been the focus of many MS researchers. Some studies have found evidence of an interaction between low vitamin D and a common MS genetic variant, called DRB1*1501. The combination appears to boost the risk of getting the disease.
Low vitamin D is viewed by some experts as a potential environmental trigger. "About 35% of all North Americans have low vitamin D," Weiner says. There is some evidence, he says, that MS patients have even lower vitamin D than the general population.
''If you measure vitamin D during an acute [MS] attack, the vitamin D levels go way down," Weiner says. When a patient is in remission, the levels are closer to normal, says Weiner, who has received grants from Teva for basic science research and consulted for Biogen Idec and Merck Serono.