Scientists behind the trial say they are "on the brink of a new class of treatments" and that the findings take us another step closer to stopping disease progression in MS.
My instinct is that we are on the brink of a new class of treatments to stop MS progression
Dr Nick Cunniffe
A combination of metformin, a diabetes drug, and clemastine, an antihistamine, can help repair myelin - the protective coating around nerves, which gets damaged in multiple sclerosis (MS) causing symptoms like fatigue, pain, spasms and problems with walking.
This is according to early findings from the phase two clinical trial, CCMR-Two, carried out by researchers at the University of Cambridge's Department of Clinical Neurosciences, and funded by the MS Society.
The scientists say the results take us another step closer to finally being able to stop disease progression in MS. However, they stress that people should not attempt to acquire the drugs outside a clinical trial, as further research is needed to fully understand their efficacy and safety in MS.
Previous evidence from animal studies showed that metformin enhances the effect of clemastine on myelin repair, but until now the two drugs had never been tested together in people. News of the latest trial was presented today at this year's European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) - one of the world's biggest MS research conferences.
"I am increasingly sure that remyelination is part of the solution to stopping progressive disability in MS," said Dr Nick Cunniffe, a clinical lecturer in Neurology at Cambridge, who led the CCMR-Two trial.
"We still need to research the long-term benefits and side effects before people with MS consider taking these drugs. But my instinct is that we are on the brink of a new class of treatments to stop MS progression, and within the next decade we could see the first licensed treatment that repairs myelin and improves the lives of people living with MS."
Over 150,000 people live with MS in the UK. While there are around 20 disease modifying therapies or people with relapsing MS, and some emerging for active progressive MS, tens of thousands of people remain without effective treatment.
Those drugs that do exist only work on one aspect of the condition - the immune system. They don't stop the gradual nerve damage that leads to long-term disability. The scientists say that finding ways to protect nerves from damage, and boosting the body's natural ability to put myelin back onto nerves, could be a way in.
"We desperately need ways to protect nerves from damage and repair lost myelin, and this research gives us real hope that myelin repair drugs will be part of the armoury of MS treatments in the future," said Dr Emma Gray, Director of Research at the MS Society. "These results are truly exciting, and could represent a turning point in the way MS is treated."
Some 70 people with relapsing MS took part in the trials for six months, half of whom took the drug combination and half took a placebo. The primary outcome used to gauge the effectiveness of the drug was a "visual evoked potential" test, which measures how quickly signals travel between the eyes and the brain. The speed of signals slowed down in the placebo group over the course of six months, but remained constant in the drug group.
While the primary outcome was positive, scientists point out that people did not feel better on the drugs. The benefit from myelin repair is to insulate and protect damaged nerves, preventing them from degenerating over years. Researchers believe that drugs that promote remyelination will have an effect on disability in the long term, which will be the subject of further research.
Researchers argue that MS is just the beginning. Finding ways to protect the brain before irreversible damage sets in, is vital across all neurodegenerative conditions from Alzheimer's to Parkinson's, diseases that together cost the UK hundreds of billions and place an enormous burden on the NHS and carers.
Hannah Threlfell, 43, from Abington was diagnosed with relapsing MS in 2019 after experiencing optic neuritis. She joined the CCMR-Two trial in the hope she could help future generations.
"Before I was diagnosed, I sat through a talk from MS specialist, Professor Alasdair Coles, about groundbreaking MS research. Even though I didn't know I had it then, I remember thinking how incredible it was that so much had been achieved. And now I have MS, joining the trial was a no brainer," said Threlfall, a former teacher who has recently become a curate.
"I love helping and I know being on this trial will make a difference to someone else in the future - even small ripples have long-lasting effects! This research gives me even more reason to believe that in my lifetime everyone with MS will have treatments that work for them."
CCMR-Two is being funded by donations to the MS Society's Stop MS Appeal. The appeal hopes to raise £100 million by the end of 2025 to help find treatments that could slow or stop the build-up of disability for everyone with MS.
