Early clinical trial results from Cambridge suggest that combining the diabetes drug metformin with the antihistamine clemastine can partially repair nerve damage in multiple sclerosis (MS).
The CCMR Two trial, funded by the MS Society, recruited 70 patients with relapsing MS. Half received the drug combination while the rest were given a placebo for six months. Tests showed that electrical signals between the eyes and brain travelled faster in those on the treatment, indicating some repair to the protective myelin sheath around nerves. However, the effect – an improvement of just 1.3 milliseconds – was too small for patients to notice benefits in vision or disability during the short study.
Lead researcher Dr Nick Cunniffe called the findings “exciting” and said they could herald a new class of therapies for MS. While current drugs largely focus on controlling the immune system, remyelination therapies aim to restore damaged nerve coatings and prevent progression of disability.
Clemastine had previously shown modest results in trials, but pairing it with metformin appeared to boost its effect. Still, researchers cautioned that the treatment is not yet ready for clinical use, with many patients experiencing side effects such as fatigue and diarrhoea.
Emma Gray of the MS Society described the results as an important proof of concept: “We would not expect them to have a clinical benefit after only six months. It will take longer for this to be seen.”
Globally, nearly 3 million people live with MS, most diagnosed in their 30s and 40s. Progressive forms of the disease, where the body can no longer repair myelin, lead to worsening disability over time.
Experts stressed the importance of pursuing remyelination research. 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 … We need to be inspired by optimism but comfortable with learning from setbacks.”
