Disease-modifying therapy uptake in a pediatric-onset multiple sclerosis population, British Columbia, Canada

Background The treatment of pediatric-onset multiple sclerosis (POMS) is evolving as disease-modifying therapies (DMTs) undergo pediatric clinical trials. However, most DMTs remain off-label in children resulting in barriers to access and variability in treatment patterns across jurisdictions. The aim of this study was to describe trends in DMT uptake in POMS in British Columbia, Canada. Methods We utilized linked clinical and administrative datasets to identify MS with onset <18 years-of-age and assess DMT uptake from dispensed prescriptions between January 1, 1996 and March 1, 2020 in British Columbia, Canada. Results Of 173 POMS cases (median follow-up = 11.5 years), 32 (18%) filled a DMT prescription <18 years-of-age; 76 (44%) did so at any age. Moderate-efficacy therapies (beta-interferons/glatiramer acetate/teriflunomide/dimethyl fumarate) were the initial DMT in 60 cases (79%) overall, however by the end of follow-up a high-efficacy therapy was the most recent DMT dispensed for 52/76 cases (68%). After 2016, anti-CD20 monoclonal antibodies became the most common DMT class dispensed. Conclusions Moderate-efficacy therapies were the more common initial DMT dispensed for individuals with POMS, but more than two-thirds eventually received a high-efficacy therapy. Only a minority of POMS cases were first dispensed a DMT under age 18 years.