Current therapies for multiple sclerosis (MS) attempt to reduce the inflammatory process that damages the myelin sheath. However, none are able to reverse the course of the disease.
Researchers from the University of California in San Francisco carried out a crossover clinical trial in which patients with MS and optic nerve damage were given antihistamine clemastine or placebo for 90 days, before switching for 60 days.
The team measured visual evoked potentials (VEPs), a measurement of conduction speed through the visual pathway that serves as a marker for remyelination.
The results showed that treatment with the drug significantly reduced VEP time by an average of 1.9 milliseconds per eye, compared with placebo.
The researchers, who reported their findings at the American Academy of Neurology annual meeting
, said that although the improvement in VEP was modest, the results could herald new treatments that enhance the brain’s reparative capacity.
 Green A, Gelfand J, Cree B et al. Positive phase II double-blind randomized placebo-controlled crossover trial of clemastine. Presented at: AAN 68th Annual Meeting; 15–21 April 2016; Vancouver, Canada.