Early Treatment Extends Time to First Multiple Sclerosis Symptom in People with Radiologically Isolated Syndrome

Summary: Researchers investigated whether it is possible to prevent or delay time to multiple sclerosis (MS) symptoms through early treatment. They conducted a randomized clinical trial in people at-risk of MS with radiologically isolated syndrome (RIS) and found that those who were treated with the disease-modifying therapy (DMT), teriflunomide, had a reduced risk of MS symptoms compared to those taking a placebo (no active drug). This study provides further evidence that early intervention can prevent or delay time to MS symptoms.

Background: Radiologically isolated syndrome (or RIS) is the earliest detectable phase of MS. People with RIS have lesions (tissue damage) in their central nervous system (i.e. brain and spinal cord) suggestive of MS as seen by magnetic resonance imaging (MRI), but do not have any clinical symptoms of MS. People with RIS are at-risk of future clinical demyelinating events and MS diagnosis.

Details: Researchers tested whether MS can be prevented or delayed in people with RIS with early treatment. A multicentre randomized clinical trial took place in three countries (France, Switzerland and Turkey) to investigate the effect of treatment with the DMT, teriflunomide, over a 96-week period compared to those taking a placebo (no active drug treatment). They examined whether treatment would delay time to the first MS symptoms or a neurologic event (e.g., relapses and/or clinical progression) over this period. A total of 89 participants were enrolled in the clinical trial that examined clinical, MRI, and patient-reported outcomes at the start of the study and over a three-year follow-up period.

Results: Researchers found that the time to first MS symptoms or a neurologic event was significantly extended in those being treated with the DMT compared with placebo. Those treated with the DMT had a 72% reduction in the risk of MS.

Impact: There are now two clinical trials that provide evidence for the benefits of early treatment in preventing or delaying symptomatic MS (refer to ARISE clinical trial here). There is a growing body of evidence suggesting earlier treatment is beneficial in delaying longer-term disability accumulation and in improving health outcomes, and this may extend to those with RIS. Further research is needed to better identify those with RIS or in an early phase of MS who would most benefit from early treatment.


Article published in JAMA Neurology on August 21, 2023 – Teriflunomide and Time to Clinical Multiple Sclerosis in Patients With Radiologically Isolated Syndrome. The TERIS Randomized Clinical Trial. Link to article – here.