Early relapse rate was no different in a group of stable multiple sclerosis (MS) patients who switched to oral therapy from injectibles compared to those who remained on their baseline treatment.
There is a lack of data to highlight the risk of disease reactivation in MS patients who switch from an injectable therapy to an oral formulation. In order to examine the risk of relapse and disease progression in these patients, Steve Vucic, MBBS, PhD, of the Department of Neurology at Westmead Hospital in Westmead, Australia, and colleagues compared stable patients in the MSBase cohort who switched from interferon β/glatiramer acetate (INFβ/GA) to an oral therapy with a control group who remained on INFβ/GA. The results of the study were published in the European Journal of Neurology.
Participants included in the study ranged from age 18 to 75 years with disease stability on INFβ/GA for at least 12 months. MS stability was defined as no clinical evidence of relapse, no increase in T2 lesions or gadolinium-enhancing lesions on MRI, and a stable disability score.
In total, 396 participants who switched to oral therapy were matched to 396 participants who remained on injectable therapy. Participants in the switch group tended to have more previous therapies, were older, and had a longer duration of disease. Most of the participants switched to fingolimod (71.2%, N=282), with 16.2% (N=64) switching to dimethyl fumarate (DMF) and 12.6% (N=50) to teriflunomide. The most cited reasons for switching included convenience (N=64/217, 29.5%) and intolerance (N=68/217, 31.3%).
Among the 792 matched participants, 6-month relapse rate was 6.9% (N=55). The researchers found no differences between the groups for relapse in months 1 to 6 (7.3% in switch vs 6.6% in control; P(McNemar)=0.675). Further, there was no observed difference in the mean 6-month annualized relapse rate (ARR) (0.2 vs 0.2; P(signed-rank)=0.4931) or rate of relapse (HR 1.22, 95% CI 0.70-2.11) at 6-months between the groups.
There were also no observed differences between the groups for confirmed progression (2.3% vs 1.0%, P(McNemar)=0.269) or for the rate of first disability progression events (HR 1.43, 95% CI: 0.63-3.26). They also found no difference in the rate of relapse after 6 months between oral agents used or length of washout period.
“Our results suggest that early relapse in previously stable patients following a switch to oral agents was rare (only 7.3% of 396 switchers recorded a relapse within 1–6 months post-switch),” the authors write.