Injectable Disease Modifying Agents in Multiple Sclerosis: Pattern of Medication Use and Clinical Effectiveness

Association of oral disease-modifying agents and their adherence trajectories with annual relapses in multiple sclerosis

BACKGROUND

Real-world effectiveness can vary across oral disease-modifying agents (DMAs) and their adherence trajectories in patients with multiple sclerosis (MS). However, previous studies have not considered longitudinal adherence patterns while evaluating oral DMAs.

OBJECTIVES

This study aimed to evaluate the association of oral DMAs and their adherence trajectories with annualized relapse rate (ARR) in patients with MS.

METHODS

This retrospective observational cohort study based on the 2015-2019 MarketScan Commercial Claims and Encounters Database involved continuous enrolled adults (18-64 years) with ≥1 MS diagnosis (ICD-9/10-CM:340/G35) and ≥ 1 oral DMA prescription. Patients were grouped into incident fingolimod (FIN), teriflunomide (TER), and dimethyl fumarate (DMF) users based on the index DMA with a one-year washout period. Annual DMA adherence trajectories based on the monthly Proportion of Days Covered (PDC) one year after treatment initiation were identified using Group-Based Trajectory Modeling (GBTM). The validated claims-based ARR was evaluated during the one-year follow-up period using generalized boosted model-based inverse probability treatment weights with negative binomial regression model.

RESULTS

The study cohort consisted of 994 MS patients who initiated with FIN (23.0%), TER (22.3%), and DMF (54.7%) during the study period. GBTM grouped eligible patients into three adherence trajectories: complete adherers (59.2%), slow decliners (23.8%), and rapid decliners (17.0%). The proportion of complete adherers varied across the oral DMAs (FIN: 67.1%, TER: 55.4%, and DMF: 57.4%). The negative binomial regression modeling revealed that, while there was no difference in ARR across the three DMAs, rapid decliners (adjusted incidence rate ratio[aIRR]: 1.6, 95% CI: 1.1-2.4) had a higher rate of relapses compared to completely adherent patients. The type of oral DMAs did not moderate the relationship between ARR and the adherence trajectory groups.

CONCLUSIONS

Adherence trajectories classified as rapid decliners were associated with a higher ARR than complete adherers after adjusting for their type of oral DMAs. Longitudinal medication adherence patterns are critical in reducing relapse rates in MS.

Comparative adherence trajectories of oral disease-modifying agents in multiple sclerosis

STUDY OBJECTIVE

This study compared the adherence trajectories of fingolimod (FIN), teriflunomide (TER), and dimethyl fumarate (DMF) users with multiple sclerosis (MS) as there is limited evidence regarding the comparative adherence patterns of different oral disease-modifying agents (DMAs).

DESIGN

A retrospective cohort study DATA SOURCE: 2015-2019 IBM MarketScan Commercial Claims Database.

PATIENTS

Adults (≥18 years) with MS (International Classification of Diseases [ICD]-9/10-Clinical Modification [CM]:340/G35) diagnosis and ≥1 DMA prescription.

INTERVENTION

Incident FIN-, TER-, or DMF use based on the index DMA with 1 year of washout period.

MEASUREMENTS

The DMA adherence trajectories based on the proportion of days covered (PDC) were examined using the Group-Based Trajectory Modeling (GBTM) 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 a reference category.

MEASUREMENTS AND MAIN RESULTS

The study cohort consisted of 1913 patients with MS who were initiated with FIN (24.2%, n = 462), TER (24.0%, n = 458), 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 patients 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 DMF (adjusted odds ratio [aOR]: 2.32, 95% confidence interval [CI]:1.57-3.42) and TER (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 were more likely (aOR: 1.50, 95% CI: 1.06-2.13) to be slow decliners compared with FIN users.

CONCLUSION

Teriflunomide and DMF were associated with poorer adherence trajectories than FIN. More research is needed to evaluate the clinical implications of these adherence trajectories of oral DMAs to optimize the management of MS.