People with multiple sclerosis (MS) who are treated with intensive therapy, especially soon after diagnosis, have a lower risk of developing secondary progressive MS.
Moreover, patients with early signs of MS, initially treated with any disease-modifying therapy, experience better outcomes than untreated patients. These are the results of a prospective study published online in the Journal of the American Medical Association (JAMA) on January 15.
As many as 85 percent of patients with MS have the relapsing-remitting form, characterized by periods of symptoms followed by remission. Several disease-modifying therapies, such as fingolimod, alemtuzumab, natalizumab, glatiramer acetate, and interferon beta, help reduce relapse rates and severe disability.
However, within two decades of the start of the disease, 80 percent of untreated patients will develop secondary progressive MS, a stage where disability gets progressively worse, according to the researchers of the current JAMA study.
To investigate the relationship between disease-modifying therapies and the risk of developing secondary progressive MS, an international team of researchers collected data from 1,555 patients—72 percent female; average age 35 at the start of the study—with clinically defined MS. The researchers gleaned data from 1998 to 2012 from three sources: untreated patients from the University Hospital of Wales; treated patients from MSBase, an observational group of real-world data of patients in 29 countries; and additional patients who were treated with alemtuzumab in Europe before it was licensed.
All patients had been classified as having relapsing-remitting MS and at least one Expanded Disability Status Scale (EDSS) score within six months before the study and at least two EDSS scores after the start of the study. The patients had a minimum follow-up of four years. To assess who developed secondary progressive MS, the researchers defined it based on disability progression and prior relapses.
The rate of developing secondary progressive MS was observed between patients who received disease-modifying therapies and untreated patients; between those taking fingolimod, natalizumab, or alemtuzumab and those prescribed glatiramer acetate or interferon beta; and between those who received treatment within five years and those who were treated after five years of diagnosis, the researchers reported.
Untreated and treated patients were matched based on age, sex, annualized relapse rate in the year before baseline, EDSS score, and disease duration.
Initial treatment with fingolimod, alemtuzumab, or natalizumab was associated with a lower risk of developing secondary progressive MS compared to initial treatment with glatiramer acetate or interferon beta.
At five years, 7 percent of patients who initially received fingolimod, alemtuzumab, or natalizumab had developed secondary progressive MS compared to 12 percent of those who initially received glatiramer acetate or interferon beta. Meanwhile, 27 percent of untreated matched patients developed secondary progressive MS.
Patients who were treated with either glatiramer acetate or interferon beta within five years of diagnosis had a lower conversion rate than those who started treatment later (3 percent versus 6 percent).
Eight percent of patients who were prescribed fingolimod, alemtuzumab, or natalizumab within five years of disease developed secondary progressive MS compared to 14 percent of those who started taking these medications later.
The study suggests treatment with aggressive disease-modifying therapies within five years of diagnosis may lower the risk of developing secondary progressive MS, but the findings did not distinguish between preventing and delaying this MS phase.
"These findings, considered along with these therapies’ risks, may help inform decisions about disease-modifying therapy selection," the researchers concluded.
