Switching from injectable platform therapies to oral first-line therapies in patients with clinically stable RRMS does not increase the risk of disability accumulation, research shows.
A study of more than 3,000 patients in the Danish Multiple Sclerosis Registry compared outcomes in those who switched from interferon-β or glatiramer acetate to either dimethyl fumarate (DMF) or teriflunomide (TFL) versus those who stayed on injectables.
It found a comparable risk of 6-month confirmed Expanded Disability Status Scale (EDSS) worsening in both groups.
“The HRs [Hazard Ratios] for switchers compared with stayers were 1.15 (95% CI 0.88 to 1.50, p for difference = 0.31) for DMF and 1.16 (95% CI 0.92 to 1.46, p for difference = 0.21) for TFL,” the study authors said.
However the risk of suffering any relapse tended to decrease when switching to DMF and increase when switching to TFL.
“The HRs for switchers compared with stayers were 0.73 (95% CI 0.51 to 1.04) for DMF and 1.25 (95% CI 0.96 to 1.63) for TFL.”
Annualised relapse rates within switchers were 0.01 for DMF and 0.04 for TFL during the first year and 0.05 and 0.08 respectively during the entire treated periods.
The study, published in the Journal of Neurology, Neurosurgery and Psychology, also showed the risk of treatment discontinuation due to disease activity was marginally lower in patients who switched to DMF, and higher in patients switched to TFL.
The risk of stopping treatment due to adverse events was relatively lower among patients switching to TFL.
“In this nationwide cohort study, we found no evidence to suggest that switching from injectable platform MS therapies, that is, IFNβ or GA, to first-line oral therapies, DMF or TFL, is associated with an increased risk of disability worsening compared with continued treatment with injectable therapies,” the study said.
“Assuringly, we reached the same overall conclusions when treating treatment exposure as a time-varying variable and having a single, common definition of baseline for all patients.”
“Overall, in patients treated with injectable MS therapies and no recent evidence of MS activity, switching to first-line oral DMTs for convenience can be viewed as a safe strategy,” the researchers concluded.
An accompanying editorial said the study was clinically important because treatment switches were so common in everyday practice.
“They used high quality data combined with substantial statistical power and adequate statistical methods, and they have, like another study, come to the safe conclusion that lateral shifts from injectables to moderate efficacy oral DMTs in patients with MS with stable disease does not worsen the disease,” wrote Professor Nils Koch-Henriksen of Aarhus University Hospital.