For the first time there is biological evidence of repair of damaged myelin in the human brain. A new study suggests that an investigational drug for multiple sclerosis (MS) may repair damaged myelin, the fatty material that protects nerves. This study advances the field of neuro-reparative therapies.
82 people who had their first incident of acute optic neuritis were selected for the phase 2 study. Acute optic neuritis is a disease that typically affects one eye and is characterized by inflammation, damage to the nerve fibers and loss of myelin within the optic nerve. An estimated 50% of the people with optic neuritis will later develop multiple sclerosis.
After treatment with high dose steroids, all participants were randomly selected with equal probability to receive either the experimental antibody, called anti-LINGO-1, or a placebo once every four weeks, for a total of six doses. They were then assessed every four weeks for six months and a final visit at eight months. The recovery of the optic nerve latency in the damaged eye at six and eight months was compared to the normal unaffected eye at the start of the study, in order to evaluate the drug’s effectiveness in repairing myelin.
The main finding of the study focused on the latency of the visual evoked potential (VEP), a test that measures the visual system’s ability to conduct electrical signals between the retina and the brain. The results showed that the people who had significantly improved conduction as measured by latency recovery were the ones treated with the experimental drug and did not miss more than one dose (per protocol population). At six months,they improved on average by 7.55 milliseconds, i.e. 34 percent, compared to placebo. The effect continued to eight months with an average improvement of 9.13 milliseconds or 41 percent over placebo.
The percentage of subjects whose VEP latency in the affected eye recovered to normal or nearly normal (within 10 percent of the normal eye) was 26% of those who received the placebo and a little over double, 53% of those who received the drug. A substudy using an exploratory method of measuring latency called multifocal VEP revealed similar treatment effects.
Lead author of the study Diego Cadavid, MD, with Biogen in Cambridge, Mass., and a fellow with the American Academy of Neurology, says that although this drug for MS has potential to repair myelin, more studies are needed to evaluate whether these changes lead to clinical improvement. A second study of anti-LINGO-1 in people with multiple sclerosis is ongoing.
This study was released today and will be presented at the American Academy of Neurology’s 67th Annual Meeting in Washington, DC, April 18 to 25, 2015.
