A drug, which reduces relapse rates in patients with multiple sclerosis (MS), might also be useful in preventing vision loss, according to researchers at the University of Pennsylvania School of Medicine. The drug called natalizumab (brand name Tysabri) is commonly used in MS patients to reduce disability and to also slow down possible relapse.
Vision loss is one of the most debilitating symptoms in patients suffering from relapsing MS. The current review analyzed the results of two trials involving 2,138 men and women. The trials called AFFIRM and SENTINEL, had participants with recurring MS.
Over 50 percent of the participants in the trials were given Tysabri for two years. They received Tysabri once every four weeks. Vision was evaluated using an eye chart that had low-contrast letter imprinted on it.
Researchers found that patients taking Tysabri had a 47 percent reduced loss of eyesight as compared to patients on a placebo. The study was funded by Tysabri makers Biogen Idec and Elan.
"Not only does natalizumab prevent the worsening of vision loss in people with relapsing MS, but it is also associated with significant reductions in the likelihood of sustained vision loss due to inflammatory demyelination of nerve fibers that connect to the eye, a common cause of visual loss in MS,” said lead author Laura J. Balcer, an associate professor of neurology at Penn.
However while Tysabri is promising, the risks must also be evaluated. The drug is known to cause a fatal, but rare condition called progressive multifocal leukoencephalopathy (PML).
The details of the study appear in the April 17 issue of Neurology.
