Early findings from a Cambridge-led clinical trial suggest that combining a common diabetes drug with an antihistamine can help repair nerve damage in people with multiple sclerosis (MS).
The CCMR Two trial tested metformin alongside clemastine, an antihistamine previously shown to encourage myelin repair, in 70 patients with relapsing MS. After six months, electrical tests revealed improved nerve function, though the effect was too small for patients to notice in their symptoms.
“I feel like we’re at this precipice of a new class of therapies for MS and that’s why this is exciting,” said Dr Nick Cunniffe, the neurologist leading the study.
MS affects nearly 3 million people worldwide and arises when the immune system damages the myelin sheaths that insulate nerves, slowing or blocking signals between the brain and body. Existing drugs mainly target the immune system but do not repair damage.
In the Cambridge study, patients taking the drug combination showed electrical signals travelling 1.3 milliseconds faster along damaged nerves compared with those on placebo. Though modest, the results suggest that remyelination – restoring protective myelin – is possible.
Emma Gray of the MS Society, which funded the study, said the results were a “positive proof of concept” but cautioned that clinical benefits may take longer to appear.
The drugs are not yet ready for use outside trials, as clemastine can cause fatigue and metformin may cause gastrointestinal side effects. Researchers stressed that the approach would not restore nerves that have already died but could protect those still intact.
Jonah Chan, a neurology professor at UCSF, called remyelination “the critical path to preventing permanent disability in MS” and urged continued trials despite setbacks.
The findings were presented at the European Committee for Treatment and Research in Multiple Sclerosis conference in Barcelona.
