A groundbreaking clinical trial led by researchers at the University of Cambridge has demonstrated that a combination of two existing drugs could help repair nerve damage in people with multiple sclerosis, potentially opening the door to a new class of MS treatments.
The CCMR-Two trial, led by Dr. Nick Cunniffe, academic neurologist at Cambridge, tested the combination of metformin, a common diabetes medication, with clemastine, an antihistamine, in 70 people with relapsing MS over six months. The study aimed to repair myelin, the protective membrane that wraps around nerve cells and becomes damaged in MS, causing symptoms such as fatigue, pain, spasms and problems with walking.
Trial Design and Results
The randomized, placebo-controlled trial divided participants equally, with half receiving the drug combination and half receiving a placebo. Researchers measured how quickly signals traveled between the eyes and the brain to assess nerve function.
The results showed that while signal speed slowed down in the placebo group over the six-month period, it remained constant in the drug group, suggesting a degree of boost to nerve function. This maintenance of nerve signal speed indicates potential myelin repair, even though participants did not report subjectively feeling better on the drugs.
Previous evidence from animal studies had found that metformin enhanced the effect of clemastine on myelin repair, but this marked the first time the two drugs were tested together in humans.
Clinical Significance and Safety Profile
While some participants experienced side effects including fatigue and diarrhea, no serious adverse events occurred during the trial. The researchers believe the benefit of myelin repair extends beyond immediate symptom relief, as it helps insulate and protect damaged nerves, preventing them from degenerating over years.
"I am increasingly sure that remyelination is part of the solution to stopping progressive disability in MS," said Dr. Cunniffe. "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."
Addressing Unmet Medical Need
More than 150,000 people live with MS in the UK, with nearly 3 million affected worldwide. While current therapies work on the immune system, none stop the gradual nerve damage that leads to long-term disability, representing a significant unmet medical need.
Dr. Emma Gray, director of research at the MS Society, which funded the trial, emphasized the potential impact: "These results are truly exciting, and could represent a turning point in the way MS is treated. 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."
Patient Perspective and Future Outlook
Hannah Threlfall, 43, from Abington, was diagnosed with relapsing MS in 2019 and participated in the trial. "It would mean everything to find a way to stop MS progressing and would be the answer to the prayer," she said. "This research gives me even more reason to believe that in my lifetime everyone with MS will have treatments that work for them."
The researchers believe that drugs promoting remyelination will have effects on disability in the longer term, beyond the six-month trial period. The trial results were presented at the European Committee for Treatment and Research in Multiple Sclerosis in Barcelona, with publication in a peer-reviewed journal expected.
Experts emphasize that more research is needed before anyone considers taking these medications outside of clinical trials, but the findings represent a significant step forward in MS treatment development.
