Objective:

To assess the safety and effectiveness of high-efficacy disease-modifying therapies (DMT) in children with multiple sclerosis (MS).

Background:

Compared to adults, children with MS experience more frequent relapses and earlier disability. Historically, children with MS have been assigned lower efficacy DMTs, due to their established safety profiles. However, the generally favorable experience with early use of high-efficacy DMTs in adults with MS may change the care of children. There are relatively few case series describing the outcomes of high-efficacy DMTs in children with MS. 

Design/Methods:

We conducted a single-center retrospective cohort study of children with MS treated by a pediatric MS specialist between August 2015 to November 2022. Inclusion criteria included an MS diagnosis according to 2017 McDonald before age 18 and treatment with at least 2 DMT doses and at least 1 subsequent clinical evaluation. Data was extracted from the electronic medical record using standardized data collection forms. The primary outcome was frequency of clinical relapse after DMT initiation. Secondary outcomes included time to development of new or enlarging T2 hyperintense lesions and/or gadolinium-enhancing lesions.

Results:

Twenty-four patients met inclusion criteria, with a mean age of 14.9 (standardized mean difference: 2.88). DMTs included rituximab (n=15), ocrelizumab (n=5), and natalizumab (n=4). Seventy percent (n=17) had a symptomatic infection during treatment. Fifty percent (n=12) were infected with SARS-CoV-2, one of whom was hospitalized but did not require ICU level of care (rituximab, n=1). Other side effects included lymphopenia (n=3), neutropenia (n=2), hypogammaglobulinemia (n=2). Two clinical relapses were reported on natalizumab. No clinical relapses were reported in patients receiving either rituximab or ocrelizumab. 

Conclusions: