A trial led by the University of Cambridge has found early evidence that combining a common diabetes drug with an antihistamine can help repair nerve damage in multiple sclerosis (MS).
The CCMR Two trial tested metformin, widely used for type 2 diabetes, alongside clemastine, an antihistamine previously shown to encourage myelin repair. Myelin is the protective coating around nerve fibres that is attacked in MS, leading to progressive disability.
Seventy patients with relapsing MS took part, with half receiving the drug combination and half a placebo for six months. The results showed improved nerve conduction, measured by the speed of electrical signals between the eyes and brain, but the effect was modest—an improvement of 1.3 milliseconds—and too small for patients to notice changes in vision or disability.
Lead researcher Dr Nick Cunniffe described the results as “exciting” and a sign that MS patients may be “at the precipice of a new class of therapies.” However, he cautioned that longer trials would be needed to demonstrate tangible clinical benefits.
Side effects were common, with patients experiencing fatigue from clemastine and diarrhoea from metformin, and researchers stressed that the drugs should not be used outside clinical studies.
Emma Gray of the MS Society called the results a “positive proof of concept,” noting that benefits are unlikely to be visible within just six months. Jonah Chan, a neurology professor at UCSF, said remyelination is crucial to preventing permanent disability: “It is also the only immediate hope for restoring function, albeit people have to be realistic about in what contexts it can restore function.”
Globally, nearly 3 million people live with MS, including more than 150,000 in the UK. Most are diagnosed in early adulthood, with symptoms ranging from tingling and balance problems to progressive speech and mobility issues. Researchers hope therapies that promote remyelination can slow or even reverse some of the disease’s effects.
