OBJECTIVES: The oral Disease-Modifying Agents (DMAs) such as fingolimod (FIN), teriflunomide (TER), and dimethyl fumarate (DMF) are convenient alternatives to injectable DMAs for Multiple Sclerosis (MS). However, there is limited evidence regarding the comparative adherence patterns across different oral DMAs. This study compared the adherence trajectories between FIN, TER, and DMF users with MS.

METHODS: A retrospective longitudinal study was conducted involving adults (≥18 years) identified with MS (ICD-9/10-CM:340/G35 and a DMA prescription) from the 2015–2019 IBM MarketScan Commercial Claims Database. Patients were classified as incident FIN-, TER- or DMF-users based on the index DMA with one year of washout period. The DMA adherence trajectories based on Proportion Days Covered (PDC) were examined using Group-Based Trajectory Modeling (GBTM) during the one year after the treatment initiation. Generalized boosting models (GBM)-based Inverse Probability Treatment Weights (IPTW) were incorporated in multinomial logistic regression to assess the comparative adherence trajectories across oral DMAs with FIN group as reference category.

RESULTS: The study cohort consisted of 1,913 MS patients who were initiated with FIN (24.2%,n=462), TER (23.9%,n=468), and DMF (51.9%,n=993) during 2016–2018. The adherence rate (PDC≥0.8) among FIN, TER, and DMF users was found to be 70.8%(n=327), 59.6%(n=273), and 61.0%(n=606), respectively. The GBTM grouped study subjects into three adherence trajectories – Complete Adherers-59.1%, Slow Decliners-22.6% and Rapid Discontinuers-18.3%. The multinomial logistic regression model involving GBM-based IPTW revealed that TER (adjusted odds ratio [aOR]-2.32, 95% CI:1.57-3.42) and DMF (aOR-2.50, 95% CI:1.62-3.88) users had higher odds to be rapid discontinuers relative to FIN users. In addition, TER users are more likely (aOR-1.50, 95% CI:1.06-2.13) to be slow decliners compared to FIN.

CONCLUSIONS: Teriflunomide and dimethyl fumarate were associated with poorer adherence trajectories than fingolimod. More research is needed to evaluate the clinical implications of these adherence trajectories of oral DMAs for the management of MS.