A Cambridge-led clinical trial has raised hopes for a new class of therapies in multiple sclerosis (MS) after finding early evidence that damage to the nervous system can be partially repaired.
The CCMR Two trial tested a combination of metformin, a common diabetes drug, and clemastine, an antihistamine, in 70 people with relapsing MS. After six months, patients on the treatment showed faster electrical signalling between the eyes and brain compared with those on placebo – a sign of improved nerve function.
While the effect was modest – just 1.3 milliseconds faster – researchers said it showed drugs could stimulate remyelination, the repair of protective coatings around nerve fibres that are damaged by the disease.
“It’s smaller than we were hoping for,” said trial lead Dr Nick Cunniffe of the University of Cambridge, presenting results at the European Committee for Treatment and Research in Multiple Sclerosis in Barcelona. “But the drugs have a biological effect to promote remyelination. People should not expect to feel better after six months – this will take longer.”
Nearly 3 million people worldwide live with MS, including more than 150,000 in the UK. Current treatments focus on slowing immune attacks, but few options exist to restore lost function once myelin is damaged.
Emma Gray, research director at the MS Society, called the findings “really positive proof of concept results” that should be followed up in larger, longer studies.
Patients reported side effects including fatigue from clemastine and diarrhoea from metformin, but researchers stressed that people should not attempt to obtain the drugs outside trials.
Jonah Chan, a neurology professor at the University of California, San Francisco, said remyelination remains the “critical path to preventing permanent disability” in MS. While results so far are modest, he added, “we need to be inspired by optimism but comfortable with learning from setbacks.”
