Comparative Effectiveness Research of Disease-Modifying Therapies for the Management of Multiple Sclerosis: Analysis of a Large Health Insurance Claims Database

Abstract

Introduction: Limited data are available on the real-world effectiveness of newer oral disease-modifying therapies (DMTs) in multiple sclerosis. The purpose of this study was to retrospectively compare the real-world effectiveness of dimethyl fumarate (DMF), fingolimod, teriflunomide, and injectable DMTs in routine clinical practice based on US claims data.

Methods: Patients newly-initiating DMF, interferon beta (IFNβ), glatiramer acetate (GA), teriflunomide, or fingolimod in 2013 were identified in the Truven MarketScan Commercial Claims Databases (N = 6372). Relapse episodes were identified based on a published claim-based algorithm and used to determine the annualized relapse rate (ARR) for the year before and after initiating therapy. Poisson and negative binomial regression was used to determine the adjusted incidence rate ratio (IRR) for each therapy relative to DMF.

Results: Significant ARR reductions in the year after initiating therapy were reported for DMF and fingolimod (P < 0.0001). Compared with DMF, the adjusted IRR (95% CI) for relapse in the year after initiating therapy was 1.27 (1.10-1.46) for IFNβ, 1.34 (1.17-1.53) for GA, 1.23 (1.05-1.45) for teriflunomide, and 1.03 (0.88-1.21) for fingolimod. Results were consistent across subgroup and sensitivity analyses.

Conclusion: These real-world data suggest DMF and fingolimod have similar effectiveness and demonstrate superior effectiveness to IFNβ, GA, and teriflunomide.

Funding: Biogen, Cambridge, MA, USA.

Keywords: Comparative effectiveness; Dimethyl fumarate; Disease-modifying therapy; Fingolimod; Glatiramer acetate; Interferon beta; Multiple sclerosis; Teriflunomide.

Fig. 1

Patient selection flow chart. DMT disease-modifying therapy, ICD-9-CM International Classification of Diseases, Ninth Revision, Clinical Modification

Fig. 2

Unadjusted annualized relapse rates for 1 year before and 1 year after DMT initiation. DMT disease-modifying therapy

Fig. 3

Adjusted IRR (95% CI) of ARR for 1 year after initiation of DMT for the interferon beta, glatiramer acetate, teriflunomide, and fingolimod cohorts relative to the DMF cohort. An IRR <1.0 means that the ARR of the comparator DMT cohort is lower than the DMF cohort, whereas an IRR >1.0 means that the ARR of the comparator DMT cohort is higher than the DMF cohort. For example, an IRR for interferon beta versus DMF of 1.27 means that the ARR in the interferon beta cohort is 27% higher than that of the DMF cohort after adjusting for baseline differences. ARR annualized relapse rate, CI confidence interval, DMF dimethyl fumarate, DMT disease-modifying therapy, IRR incidence rate ratio

Fig. 4

Adjusted IRR (95% CI) of relapse in the first year after initiation of interferon beta, glatiramer acetate, teriflunomide, and fingolimod relative to DMF for patients adherent to therapy (defined as an MPR of ≥0.8). An IRR <1.0 means that the ARR of the comparator DMT cohort is lower than that of the DMF cohort, whereas an IRR >1.0 means that the ARR of the comparator DMT cohort is higher than that of the DMF cohort. For example, an IRR for interferon beta versus DMF of 1.40 means that the ARR in the interferon beta cohort is 40% higher than that of the DMF cohort after adjusting for baseline differences. ARR annualized relapse rate, CI confidence interval, DMF dimethyl fumarate, DMT disease-modifying therapy, IRR incidence rate ratio, MPR medication possession rate