Purpose: The purpose of this study is to describe the utilization of disease-modifying treatments (DMTs) in relapsing-remitting multiple sclerosis (MS) and assess the impact of both the introduction of new drugs and treatment recommendations (local recommendation on rituximab use issued at the largest MS clinic in Stockholm and regional Drug and Therapeutics Committee (DTC) recommendation on how dimethyl fumarate should be used).
Methods: Interrupted time series analyses using monthly data on all MS patients treated with DMTs in the Stockholm County, Sweden, from January 2011 to December 2017.
Results: There were 4765 individuals diagnosed with MS residing in the Stockholm County from 2011 to 2017. Of these, 2934 (62%) were treated with an MS DMT. Since 2011, fingolimod, alemtuzumab, teriflunomide, dimethyl fumarate, peginterferon beta-1a, and daclizumab were introduced. Only fingolimod and dimethyl fumarate significantly impacted MS DMT utilization. In parallel, the use of rituximab off-label increased steadily, reaching 58% of all DMT-treated MS patients by the end of the study period. The local recommendation on rituximab was associated with an increase in rituximab use. The regional DTC recommendation on dimethyl fumarate was associated with a decrease in dimethyl fumarate use.
Conclusions: Three MS DMTs-fingolimod, dimethyl fumarate, and rituximab off-label-impacted MS DMT utilization in the Stockholm County. The associations between the treatment recommendations and the subsequent changes in MS DMT utilization indicate that such interventions can influence the uptake and utilization of new drugs used in the specialized care setting.
Keywords: Dimethyl fumarate; Drug and Therapeutics Committee; Drug utilization; Multiple sclerosis, relapsing-remitting; Rituximab.