An observational cohort study of a prospective international database of patients with multiple sclerosis has reported that medical therapy can reduce disability progression in patients with active secondary progressive MS (SPMS) who are prone to inflammatory relapses.
Brian Hoyle/MDedge News
Dr. Nathaniel Lizak
The international researchers, led by Nathanial Lizak, MMBS, of the University of Melbourne, conducted the cohort study of 1,621 patients with SPMS from the MSBase international registry, which prospectively collected the information from 1995 to 2018. Their findings were published in JAMA Neurology.
“ wrote Dr. Lizak and colleagues of the MSBase Study Group.
Therapy’s impact on disease progression
To ensure that they had timely data on the early disease course of all study patients, they researchers only included patients whose diagnosis and first documented Expanded Disability Status Scale (EDSS) score were no more than 24 months apart. At SPMS conversion, 1,494 patients had an EDSS score of less than 7 (on a scale of 0-10); during the follow-up period, 267 of them (17.9%) crossed over the threshold of 7.
Dr. Lizak and colleagues noted that early treatment during relapsing remitting MS didn’t impact outcomes after SPMS conversion.
For evaluating the MS Severity Score (MSSS), the study split the cohort into three groups depending on the efficacy of therapy: low-efficacy treatments, mostly consisting of interferon-beta and glatiramer acetate; medium-efficacy treatments, mostly fingolimod and dimethyl fumarate; and high-efficacy treatments, predominately natalizumab and mitoxantrone.
The MSSS progression slope in the cohort had an average reduction of 0.02 points per year. “For patients who experienced superimposed relapses during SPMS, a reduced MSSS progression slope during SPMS was observed among those who received disease-modifying therapies for a greater proportion of time during SPMS,” Dr. Lizak and colleagues wrote.
MSSS progression slope reduction was more pronounced in the medium- and high-efficacy groups, with a reduction of beta 0.22 (P = .06) and 0.034 (P = .002), respectively.
“Based on our models, the level of disability in patients with active SPMS who are continuously treated with high-efficacy immunotherapies would progress more slowly in comparison with the general population with MS by a mean (standard deviation) of 1.56 (4.60) deciles over 10 years,” Dr. Lizak and colleagues wrote.
While the researchers cited a number of studies that didn’t support immunotherapy for SPMS, they also did cite the EXPAND trial to support treatment with siponimod in SPMS patients (Lancet. 2018;391:1263-73). The ASCEND trial of natalizumab enrolled a largely relapse-free cohort and found no link between treatment and disability progression in SPMS (Lancet Neurol. 2018;17:405-15), and a previous report by the MSBase Study Group found no benefit of therapy when adjusted for SPMS relapse rates (Neurology. 2017;89:1050-9).
“Together with the present study, the existing data converge on the suggestion that relapses during SPMS provide a therapeutic target and a marker of future response to immunotherapy during SPMS,” Dr. Lizak and colleagues wrote.