BERLIN – Real-world data from six postmarketing surveillance studies suggest that currently available disease-modifying treatments (DMTs) for relapsing-remitting multiple sclerosis (RRMS) have long-lasting effects that are matched by reasonable tolerability.
Long-term efficacy and safety data on natalizumab (Tysabri), fingolimod (Gilenya), alemtuzumab (Lemtrada), dimethyl fumarate (Tecfidera), and teriflunomide (Aubagio) from four Swedish studies, one French study, and one international study were reported during a poster session on long-term treatment monitoring at the annual congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS).
The IMSE 1 study with natalizumab
The Immunomodulation and Multiple Sclerosis Epidemiology (IMSE) studies are Swedish postmarketing surveillance studies that were started with the launch of various DMTs in Sweden: natalizumab since 2006 (IMSE 1), fingolimod in 2015 (IMSE 2), alemtuzumab in 2014 (IMSE 3), and dimethyl fumarate in 2014 (IMSE 5).
“Postmarketing surveillance is important for determination of long-term safety and effectiveness in a real-world setting,”and her associates observed in their poster reporting some findings of the IMSE 1 study with natalizumab ( , Abstract P1232).
Ms. Kågström of the department of clinical neuroscience at the Karolinska Institute in Stockholm and her colleagues reported that data on 3,108 patients who were seen at 54 Swedish clinics had been collated via the nationwide Swedish Quality Registry for Neurological Care (). NEUROreg started out as an MS register but has since widened its remit to include other neurologic diagnoses.
For the IMSE 1 study, prospectively recorded data regarding natalizumab treatment, adverse events, JC-virus (JCV) status and clinical effectiveness measures were obtained from NEUROreg for 2,225 women and 883 men. Just over one-third (37%, n = 1,150) were still receiving natalizumab at the time of the analysis.
The mean age at which natalizumab was started was 39 years, with treatment primarily given for RRMS (81% of patients) and less often for secondary progressive multiple sclerosis (SPMS, 15%) and rarely for other types of progressive MS. The mean treatment duration was just under 4 years (47.6 months).
JCV testing was introduced in 2011 in Sweden, and this “has led to fewer treated JCV-positive patients,” the IMSE 1 study investigators reported. “This likely explains a reduced incidence of PML [progressive multifocal leukoencephalopathy],” they suggested. There were nine PML cases diagnosed in Sweden from 2008 to the data cut-off point in 2018, one of which was fatal.
JCV status from 2011 onward was available for 1,269 patients, of whom 39% were JCV positive and 61% were JCV negative. The overall drug survival rate was 72% for JCV-negative and 14% for JCV-positive patients. Improved health status was seen, as measured by the Expanded Disability Status Scale (EDSS), the Multiple Sclerosis Severity Score (MSSS), and the physical and psychological Multiple Sclerosis Impact Scale–29 (MSIS-29) components.
A total of 644 of 1,269 patients discontinued treatment with natalizumab at some point, of whom 67% discontinued because of being JCV positive. The main reason for discontinuation in JCV-negative patients was pregnancy or planning a pregnancy (38%), with lack of effect (10%) and adverse events (11%) as other key reasons for stopping natalizumab.
Ms. Kågström and her associates concluded that natalizumab was “generally well tolerated with sustained effectiveness.”