A common epilepsy drug could be the key to tackling sight loss for people with multiple sclerosis (MS), according to new findings from researchers at University College London.
The findings come from a small phase II clinical trial of 86 people which show that Phenytoin, a drug prescribed to control seizures, had a neuroprotective effect in patients with optic neuritis.
Optic neuritis is a condition in which the optic nerve becomes inflamed, resulting in pain and blurred vision and can even result in blindness. The condition is estimated to affect half of people with MS.
Patients received either Phenytoin or a placebo for three months, and retinal nerve fibre layer (RNFL) thickness was measured, at the beginning of the study, and again, six months afterwards.
Patients taking Phenytoin are reported to have 30% less damage to the RNFL compared with those who received the placebo, and the volume of the macula was 34% higher compared with controls.
Dr Raj Kapoor, who led the study at University College London (UCL), said: “These are promising results and if our findings are confirmed by larger studies, could lead to a new treatment that protects nerves from the damage caused both in optic neuritis and throughout the central nervous system in MS.”
The research was funded by the MS Society, the National Multiple Sclerosis Society and an unrestricted grant from Novartis.
A second trial into optic neuritis showed positive results for a drug still under development by pharma company Biogen. In a small trial of 82 patients, anti-LINGO-1 was shown to promote the repair of myelin, the protective sheath surrounding nerve cells which is lost in MS.
Researchers found that anti-LINGO-1 increased the speed of transmission of nerve signals from the retina to the brain, suggesting that repair to the myelin may be occurring.
Head of biomedical research at the MS Society, Dr Emma Gray, said: “This is the first indication that a drug could promote remyelination in people, which is hugely encouraging news. People with MS are in desperate need of treatments that slow or halt the progression of the condition, and repairing myelin is a promising way to do this.”
Dr Gray added: “These trial results in optic neuritis represent another positive step towards developing myelin repair treatments for people with MS.”
Both sets of findings are to be presented this week at the annual meeting of the American Academy of Neurology, in Washington, DC.
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