Background: Teriflunomid (TFM) is an oral therapy for relapsing-remitting multiple sclerosis (RRMS), which has been included in the Swedish post-market surveillance study “Immunomodulation and Multiple Sclerosis Epidemiology” (IMSE).
Objectives: To assess the long-term safety and effectiveness of TFM for patients treated in a real-world setting over time.
Methods: A large majority of MS patients are registered into the nationwide Swedish Neuro Registry (NeuroReg). The IMSE 4 study obtains descriptive data of adverse events (AEs), 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 - Five Dimensions Test (EQ-5D) and Visual Analog Scale (VAS) from NeuroReg. Effectiveness measures were assessed using the Wilcoxon Signed Rank Test and drug survival using the Kaplan-Meier curve.
Results: 609 TFM-treated patients had been included in the IMSE 4 study from March 2014 to June 2020, 70% were female and mean age at treatment start was 46 years. Mean treatment duration was 27 months and 89% of the patients had RRMS. The most common prior treatment was interferon beta or glatiramer acetate (39%) and 17% of the patients were treatment naïve. The overall one- two- and three- year drug survival rates were 73%, 59% and 48% respectively. 307 (50%) patients had discontinued treatment at some point, of which 34% started rituximab treatment (36% had no new treatment registered). The most common reasons for discontinuation were AEs (42%) and lack of effect (40%).
204 patients had been continuously treated with TFM for ≥36 months and significant changes in mean baseline values compared to values at 36 months were noted only for EDSS (2.0 ± 1.6 to 2.3 ± 1.8, n=49). All other clinical measures were stable.
A total of 68 AEs were reported of which 20 events were classified as serious (S). The most common AE category was skin and subcutaneous tissue disorders for both serious and non-serious (NS) AEs (S: 25%, NS: 21%).
Conclusions: NeuroReg proves to function well as a post-marketing drug surveillance platform, providing data regarding drug effectiveness and AEs. Patients starting TMF are older at treatment start than patients initiating most other DMTs, which may explain the lack of significant improvement in most clinical measures and the negative outcome of the EDSS scores. A longer follow-up period is needed to assess the real-world effectiveness and safety of TMF.