Early clinical trial results suggest that combining a common diabetes drug with an antihistamine may help repair nerve damage in multiple sclerosis (MS).
The Cambridge-led CCMR Two trial tested metformin, a diabetes medication, alongside clemastine, an antihistamine previously shown to stimulate myelin repair. Myelin is the protective sheath around nerves that is attacked in MS, causing slowed or blocked electrical signals and progressive disability.
Seventy people with relapsing MS took part, with half receiving the drug combination and half a placebo for six months. Tests showed that electrical signals between the eyes and brain travelled slightly faster — an improvement of 1.3 milliseconds — in those on the treatment. While too small for patients to notice benefits in vision or disability, researchers said it was proof the drugs had a biological effect.
“I feel like we’re at this precipice of a new class of therapies for MS and that’s why this is exciting,” said trial lead Dr Nick Cunniffe of the University of Cambridge.
Nearly 3 million people worldwide live with MS, which is most often diagnosed in early adulthood. Relapsing forms can progress into steady nerve loss, leading to tremors, stiffness, and in severe cases, wheelchair use.
The findings, presented at the European Committee for Treatment and Research in Multiple Sclerosis, build on earlier work showing clemastine’s limited benefits. Researchers believe metformin may enhance its remyelination potential.
Emma Gray of the MS Society called the results “really positive proof of concept,” though she noted clinical improvements may only be seen over longer treatment.
Side effects included fatigue from clemastine and diarrhoea from metformin, and scientists stressed the drugs should not be used outside clinical trials.
Jonah Chan, a neurology professor at UCSF, said: “Remyelination is the critical path to preventing permanent disability in MS … It is also the only immediate hope for restoring function, albeit people have to be realistic about in what contexts it can restore function.”
Researchers are now pushing for larger and longer studies to determine whether this approach could slow progression or restore lost abilities in MS patients.
