WASHINGTON, DC—A significant minority of patients with multiple sclerosis (MS) who were in remission for at least five years before discontinuing disease-modifying therapy (DMT) experienced disease worsening upon stopping their medication, according to research presented at the 67th Annual Meeting of the American Academy of Neurology.
Ilya Kister, MD, Assistant Professor of Neurology at the NYU Langone Multiple Sclerosis Comprehensive Care Center, and colleagues analyzed data from the MSBase Registry, an international database that collects physician-submitted data on approximately 30,000 patients, to study relapse rate and disability progression after first-line DMT is discontinued in previously stable patients.
“If and when MS patients can safely discontinue DMT treatment is an important question that frequently comes up in clinical practice, especially with regard to patients who have been clinically and radiologically stable for a long time,” the researchers said. Some patients grow tired of taking their medicine, or feel it doesn’t work, and may stop taking it with or without their doctors’ consent, said Dr. Kister, the study’s lead author. Patients also might not be able to afford medication copayments or might encounter other insurance issues, according to the National MS Society.
The researchers identified 182 patients who met their inclusion criteria. Patients were age 40 or older at baseline and had stable Expanded Disability Status Scale (EDSS) scores and no relapse for at least five years prior to baseline. Patients were treated continuously with DMT for at least three years before the therapy was discontinued, and patients were followed for at least three years after stopping their medication. Patients who reinitiated DMT within three months were considered “DMT switchers” and excluded from the analysis.
Approximately one in four patients experienced a clinician-confirmed relapse, and approximately one in three patients had confirmed disability progression. Confirmed disability progression was defined as an increase of at least one point in EDSS score above a baseline score of 1–5.5, confirmed at repeat assessment at least three months or one year later.
Reasons for stopping DMTs included lack of improvement (9%), perceived disease progression (10%), intolerance (8%), inconvenience (8%), adverse event (6%), and unknown (66%). During the post-discontinuation period (median 4.2 years), 44 (24.2%) patients had a relapse, 36 (of 113, 31.9%) had three-month disability progression, and 12 patients (10.6%) had relapse and disability progression.
DMTs were restarted by 77 of 182 patients (42%) after three or more months, with a median time to restart of 22 months. Those who restarted DMT had a 59% decrease in the rate of disability progression compared with those who did not restart DMT, researchers said. Those who did and did not restart DMT had similar relapse rates.
“Decisions regarding stopping disease-modifying therapy may have implications for short and long-term prognosis. We know a lot about what happens when therapy is started, but we know very little about what happens when therapy is stopped,” Dr. Kister said. The researchers call for a randomized DMT discontinuation trial in stable, older patients to help answer whether and when patients may stop DMT.