Teriflunomide and Radiologically Isolated Syndrome

Previous studies have demonstrated that treatment of radiologically isolated syndrome (RIS) reduces the risk for progression to multiple sclerosis (MS) in individuals at high risk who have MRI scans that meet 2009 RIS criteria (NEJM JW Neurol 2023 Feb 10 and Ann Neurol 2023; 93:604). In this industry-sponsored, multicenter, double-blind, phase 3 trial, 89 adults with RIS were randomized to receive oral teriflunomide (14 mg/day) or placebo for 96 weeks, extending up to 144 weeks in the absence of symptoms or adverse effects.

The trial was discontinued early due to slow enrollment. Time to first clinical event was extended significantly, by 72% in the adjusted analysis. MRI measures were not significantly affected, with a trend toward T2 lesio…