To Örebro University

Background: Teriflunomide (TFM) is an oral therapy for relapsing-remitting multiple sclerosis (RRMS) included in the Swedish post-market surveillance study “Immunomodulation and Multiple Sclerosis Epidemiology” (IMSE).

Objectives: To assess the safety and effectiveness of TFM with focus on patients treated at least 48 months.

Methods: Descriptive data of Extended Disability Status Scale (EDSS), Multiple Sclerosis Severity Scale (MSSS), Symbol Digit Modalities Test (SDMT), Multiple Sclerosis Impact Scale (MSIS-29), European Quality of Life - 5 Dimensions Test (EQ-5D), Visual Analog Scale (VAS) and Adverse Events (AEs) is obtained from the nationwide Swedish Neuro Registry (NeuroReg). Effectiveness measures were assessed using Wilcoxon Signed Rank Test and drug survival using Kaplan-Meier curve.

Results: 645 patients were included in the IMSE 4 study from March 2014 to April 2021, 70% were female, mean age at treatment start was 46 years and mean treatment duration was 31 months. The most common prior treatment was interferon beta or glatiramer acetate (34%) and 17% were treatment naïve. One- two- and three- year drug survival rates were 74%, 59% and 49% respectively. 340 patients (53%) have discontinued treatment with main reasons for discontinuation being AEs (41%) and lack of effect (40%). Of 68 reported AEs, 20 were serious. For both serious and non-serious AEs, skin and subcutaneous tissue disorders were the most common (25% and 21%, respectively).

At the cut-off date, 168 patients had been treated for at least 48 months. This cohort had a mean age of 48 years at treatment start and a mean treatment duration of 65 months. The majority (64%) had switched from interferon or glatiramer acetate and 12% were treatment naïve.

Significant improvement in mean values at 48 months of treatment compared to baseline were noted for SDMT in the 48-month cohort (49.1 ± 8.2 to 50.5 ± 10.0, n=35, p=0.049) while a minor worsening were noted for EDSS (2.2 ± 1.7 to 2.6 ± 2.0, n=37, p=0.017). All other tests remained stable after 4 years of treatment.

Conclusions: TMF demonstrates partly clinical improvements and stability in patients treated ⩾ 48 months but with a minor negative outcome of the EDSS scores in this cohort. A longer follow-up period is needed to assess the real-world effectiveness and safety of TMF.