Early trial results suggest that combining a common diabetes drug, metformin, with the antihistamine clemastine may partially repair nerve damage in people with multiple sclerosis (MS).
The University of Cambridge-led CCMR Two trial involved 70 patients with relapsing MS. Half received the drug combination while half were given a placebo for six months. Tests showed electrical signals between the eyes and brain travelled faster in those taking the drugs, pointing to improved myelin repair – the protective coating around nerves that is attacked in MS.
However, the improvement was small – just 1.3 milliseconds – and not enough for patients to notice any benefit in their vision or disability levels during the trial.
“It’s smaller than we were hoping for,” said lead researcher Dr Nick Cunniffe. “My conclusion is that the drugs have a biological effect to promote remyelination, but people do not feel better on these drugs over six months.”
The findings, presented at the European Committee for Treatment and Research in Multiple Sclerosis in Barcelona, provide proof of concept that remyelination drugs could slow or reverse MS progression, but longer studies are needed.
Nearly 3 million people worldwide live with MS, including more than 150,000 in the UK. Current therapies mainly target the immune system but cannot repair existing nerve damage.
Emma Gray of the MS Society, which funded the trial, called the results “really positive proof of concept”, adding: “We would not expect them to have a clinical benefit after only six months. It will take longer.”
The researchers stressed patients should not seek out these drugs outside trials due to side effects, including fatigue from clemastine and diarrhoea from metformin.
Experts say that while nerves already lost cannot be regenerated, drugs that restore myelin could prevent permanent disability and improve long-term outcomes for people with MS.
