Efficacy and tolerability of oral versus injectable disease-modifying therapies for multiple sclerosis in clinical practice

Background: The advent of oral disease-modifying therapies fundamentally changed the treatment of multiple sclerosis. Nevertheless, impressions of their relative efficacy and tolerability are primarily founded on expert opinion.

Objective: The purpose of this study was to determine whether oral disease-modifying therapies were better tolerated and/or more effective for controlling multiple sclerosis compared to injectable therapies in clinical practice.

Methods: Single-center, retrospective cohort study. 480 patients initiated oral (fingolimod, teriflunomide, or dimethyl fumarate) or injectable therapy between March 2013-March 2015 and follow-up data was collected for 5-31 months. Outcomes included on-drug multiple sclerosis activity and drug discontinuation. Cox proportional hazards models were used to control for baseline differences and sensitivity analyses using propensity-weighted matching were performed.

Results: A higher proportion of teriflunomide-treated patients experienced multiple sclerosis activity compared to those treated with injectable therapies (p = 0.0053) in the adjusted model. Breakthrough multiple sclerosis was equally prevalent among fingolimod and dimethyl fumarate-treated compared to injectable therapy-treated patients. Of patients initiating a disease-modifying therapy, 32-46% discontinued or switched treatments during the study. After controlling for baseline differences, discontinuation rates were comparable across treatment groups.

Conclusions: In this cohort, oral and injectable disease-modifying therapies were equally well tolerated, but teriflunomide appeared less effective for controlling multiple sclerosis activity than injectable therapies. Further study is needed.