The drug teriflunomide may delay first symptoms for people whose magnetic resonance imaging scans show signs of multiple sclerosis even though they do not yet have symptoms of the disease, according to a new study. 

The study, led by researchers at the University Hospital of Nice, France, involved 89 people with radiologically isolated syndrome. Half of the people were given 14 milligrams (mg) of teriflunomide daily and the other half were given a placebo. They were followed for up to two years. Radiologically isolated syndrome is diagnosed in people who do not have MS symptoms but who have abnormalities in the brain or spinal cord called lesions, similar to those seen in MS.

During the study, eight people who took the drug developed MS symptoms, compared to 20 who took the placebo. After adjusting for other factors that could affect the risk of developing symptoms, researchers found that people taking teriflunomide had a 72 percent lower risk of experiencing first symptoms than those taking the placebo.

According to the researchers, the findings suggest that early intervention with teriflunomide may be beneficial to those diagnosed with radiologically isolated syndrome, the presymptomatic phase of MS.

However, the authors said that more research is needed in larger groups of people to confirm the findings. Additionally, it is important that medical professionals are cautious when using MRI expertise to diagnose this condition, selecting only patients at risk of developing MS and not increasing MRI misdiagnoses.

The study was supported by Sanofi, the company that makes teriflunomide.

The preliminary study will be presented at the American Academy of Neurology’s 75th Annual Meeting, in Boston from April 22-27, 2023.