Immunotherapies improve long-term disability outcomes in MS

Long-term exposure to immunotherapy reduced the rate of relapses and disability progression among a large cohort of patients with MS followed for 15 years, according to findings published in Neurology.

“A proof of long-term effect of immunomodulation on the accumulation of MS-related neurological disability is the key to establishing its disease modifying properties,” Tomas Kalincik, MD, PhD, a principal research fellow in neurological outcomes at Royal Melbourne Hospital, and colleagues wrote. “Here we present a study from the largest international MS registry, whose aim was to compare worsening and improvement of disability and incidence of relapses during periods of treatment vs. no treatment with MS immunotherapies over more than 15 years of follow-up.”

Kalincik and colleagues conducted a case control study of patients with MS who were exposed to immunotherapy and had follow-up data of at least 1 year. They also examined a subset of patients with a history of follow-up care for 15 years or more.

The researchers compared 12-month confirmed increases and decreases in disability, Expanded Disability Status Scale step 6 and the rate of relapses between treated vs. untreated periods. They adjusted models regularly for patient age, sex, pregnancy status, disease course, time since first symptoms, previous history of MS relapses, disability and MRI data.

Of 14,717 patients in the observational cohort, 1,085 participants (women, 73%; mean age, 33 years) had a follow-up period of 15 or more years. Interferon-beta/glatiramer acetate was the most common immunotherapy for all patients (59%) and for patients with 15 years of follow-up data (58%). The researchers observed similar rates of disability at first visit in both the entire cohort and in patients with 15 or more years of follow-up.

All patients were less likely to have relapses (HR = 0.60; 95% CI, 0.43-0.82), worsening of disability (HR = 0.56; 95% CI, 0.38-0.82) and progression to an EDSS score of 6 (HR = 0.33; 95% CI, 0.19-0.59) while treated with immunotherapies.

Patients with 15 or more years of follow-up data available also had lower rates of relapse (HR = 0.59; 95% CI, 0.5-0.7) and worsening of disability (HR = .81; 95% CI, .67-.99). For these patients, continued treatment with immunotherapies decreased disability accrual by 19% to 44% (95% CI, 1% to 62%), risk for requiring a walking aid by 67% (95% CI, 41% to 81%) and relapse frequency by 40% to 41% (95% CI, 18% to 57%).

“This study provides class IV evidence that long-term exposure to immunotherapy not only reduces relapse activity but also prevents at least a fifth of neurological disability worsening in patients with relapsing-remitting MS,” the researchers wrote. “... Sustained, long-term immunotherapy from early stages of MS is advisable as a strategy to preserve patients’ neurological capacity over the long-term.”