Dimethyl fumarate (Tecfidera) is more effective than teriflunomide (Aubagio) at preventing relapses in patients with relapsing remitting multiple sclerosis, data from a real-world study shows.
In a population-based Danish MS Registry comparing the effectiveness of both therapies over ≈2 years in 2,236 patients with relapsing-remitting MS dimethyl fumarate showed a 42% lower relapse rate, with an absolute difference of 0.08 relapses per year between the treatment groups.
The results were replicated when the authors excluded confounding by the protective effect of pregnancy and the presence of baseline T2-hyperintense lesion counts.
No differences in 3 month or 6 month EDSS score worsening were seen between the treatment groups, a finding that the authors said was not unexpected since “confirmed EDSS score worsening is rather uncommon in patients early in the disease course with a short follow-up period and low EDSS score”.
While treatment discontinuation rates due to adverse events were almost identical for the treatments, teriflunomide was twice as likely as dimethyl fumarate to be stopped because of physician-reported disease activity.
Patients had substantial prior disease activity (annualised relapse rate 0.8–1.0), and a large proportion were previously treatment-naive (dimethyl fumarate 36%, teriflunomide 66%).
The authors acknowledged that population-based real-world studies possessed an inherent risk of unmeasured confounding, noting that they also provided “valuable information on treatment effectiveness in an applied, clinical context.”
“We provide Class II evidence of an ≈42% lower ARR in patients treated with DMF compared with patients treated with TFL. Furthermore , we provide evidence of a lower risk of a first relapse and a lower incidence of discontinuation due to disease breakthrough in patients treated with DMF after adjustment using propensity score–based methods,” they concluded.
Writing in an accompanying editorial Associate Professor Tomas Kalincik from the Royal Melbourne Hospital said the results of the current study and others showed that oral MS immunotherapies were associated with “an excellent control of relapse activity, with only minimum differences found between the agents in specific situations”.
“A pattern has begun to emerge that suggests that patients with no prior exposure to MS immunotherapy tend to benefit more from dimethyl fumarate than teriflunomide,” he wrote.
“On the other hand, studies that compared cohorts who were mostly switching from other immunotherapies did not find differences in effectiveness between the 2 agents.”
“Choosing an oral MS therapy is a complex process, with treatment effectiveness being only one of a multitude of factors that drive such decisions….the relative effectiveness of MS treatments strongly depends on the context of prior treatment history and disease activity” he concluded.