A Cambridge-led clinical trial has found that a common diabetes drug combined with an antihistamine can partially repair nerve damage in multiple sclerosis (MS), raising hopes for a new class of treatments.
The CCMR Two trial tested clemastine, an antihistamine, with metformin, a diabetes drug, in 70 people with relapsing MS. While patients did not notice improvements in symptoms after six months, electrical tests showed faster signal transmission in nerves, suggesting partial repair of damaged myelin sheaths.
“It’s smaller than we were hoping for,” said Dr Nick Cunniffe of the University of Cambridge, who led the trial. “The drugs have a biological effect to promote remyelination, but people do not feel better on these drugs over six months.”
Nearly 3 million people worldwide live with MS, which occurs when the immune system attacks the myelin coating around nerves, disrupting brain and spinal cord communication. Current treatments mainly target the immune system, but none repair damage already done.
Previous research showed clemastine could stimulate myelin repair, though with limited potency. The new study suggests metformin may enhance its effect. However, side effects such as fatigue and diarrhoea were common.
Emma Gray of the MS Society, which funded the study, called the results “really positive proof of concept” and urged follow-up trials, noting longer treatment periods may be needed to show clinical benefit.
Experts stressed the drugs should not be used outside clinical trials. Remyelination therapies could help slow or reverse progression, but cannot regenerate nerves that have already died.
Prof Jonah Chan of UCSF, who has studied remyelination, said: “I’m more convinced than ever that remyelination is the critical path to preventing permanent disability in MS. We need to pursue scientifically validated compounds from the lab to see if they really work in people.”
