Kelli Whitlock Burton
October 31, 2022
Dimethyl fumarate (DMF) could delay — or even prevent — clinical symptoms in patients with radiologically isolated syndrome (RIS), the earliest detected pre-clinical phase of multiple sclerosis.
Researchers found that DMF reduced the risk of a first acute or progressive event related to CNS demyelination by more than 80% compared with placebo.
Patients with RIS have incidental MRI abnormalities typical of multiple sclerosis (MS) but have no symptoms of the disease. The condition is usually detected when a patient seeks treatment for another issue, such as migraines or head trauma.
The study is the first randomized clinical trial to examine efficacy of a disease-modifying therapy in delaying symptoms in RIS.
“It really supports the concept of the benefit of early treatment intervention within this given MS disease spectrum,” lead investigator Darin Okuda, MD, professor of neurology at The University of Texas Southwestern Medical Center in Dallas, told delegates attending the 38th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in Amsterdam.
Topic of Debate
RIS was first identified by Okuda in 2008. Increased use of brain imaging led to the detection of patients with incidental white-matter pathology in the central nervous system on MRI. Some of the findings were nonspecific, but others were highly suggestive of demyelinating pathology based on their location and morphology in the central nervous system.
Although the prevalence of RIS is unknown, incidentally discovered white matter lesions resembling demyelination occur in an estimated 0.1%–0.7% of the general population. Up to half patients with RIS experience a first clinical MS event within 10 years.
Diagnostic criteria and whether to treat patients with RIS prophylactically has long been a topic of debate among neurologists and radiologists.
Researchers conducted the multicenter, randomized, double-blinded, placebo-controlled ARISE study in 2016, recruiting 87 patients with RIS. The majority of participants were women, and most were diagnosed in their early 40s.
Patients received oral DMF at 240 mg twice daily or placebo and were followed for 96 weeks (1 year, 10 months). Clinical assessments were completed at baseline, at weeks 48 and 96, and at the time of the first clinical event. MRI scans were performed only at the beginning and end of the study.
Those who received DMF had a significantly lower risk of experiencing a first clinical demyelinating event during the study period (aHR, 0.07; P = .005).
After adjusting for the number of gadolinium-enhancing lesions at baseline, there was a significant reduction in the number of new or newly enlarged T2-weighted hyperintense lesions, a secondary endpoint, in the dimethyl fumarate group compared with those on placebo (HR, 0.20; P = .042).
“In the future we’d like to see further studies performed to assess the impact on disability outcome measures following treatment for a meaningful amount of time,” Okuda said.
“Striking” Findings
Commenting on the findings for Medscape Medical News, Barbara Giesser, MD, a neurologist at Pacific Neuroscience Institute in Santa Monica, California, called the results “striking,” but notes questions remain.
“Up until this study we haven’t had anything like it to guide us in determining whether we should treat RIS or not,” she said. “Obviously, larger studies are needed but I think this is a very important and well-done study.”
In addition to the small sample size, Giesser noted that the study lacked data on the presence of risk factors that are known to increase RIS patients’ risk of developing MS, such as evidence of spinal cord lesions. That issue was also raised during discussion of the paper in Amsterdam.
“I don’t think this means you should treat everybody with RIS necessarily,” Giesser said. “But I think it suggests that in people with RIS, particularly if they do have risk factors, you could consider treatment with dimethyl fumarate.”
The study was funded by Biogen. Okuda has received support from Biogen and EMD Serono/Merck; and consulting fees from Alexion, Biogen, EMD Serono, Genzyme, Novartis, RVL Pharmaceuticals, TG Therapeutics, Viela Bio, Celgene/Bristol Myers Squibb, Genentech, Janssen Pharmaceuticals, and Osmotica Pharmaceuticals. Giesser reports no relevant financial relationships.
38th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) 2022: Abstract 0179. Presented October 28, 2022.
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