Objective To assess real‐world effectiveness of initial treatment with newer compared to injectable disease‐modifying therapies (DMTs) on disease activity in pediatric multiple sclerosis (MS) and clinically isolated syndrome (CIS). Methods This is a cohort study of children with MS/CIS followed at 12 clinics in the US Network of Pediatric MS Centers, who received initial therapy with newer (fingolimod, dimethyl fumarate, teriflunomide, natalizumab, rituximab, ocrelizumab) or injectable (interferon‐β, glatiramer acetate) DMTs. Propensity scores (PSs) were computed, including preidentified confounders. Relapse rate while on initial DMT was modeled with negative binomial regression, adjusted for PS‐quintile. Time to new/enlarging T2‐hyperintense and gadolinium‐enhancing lesions on brain magnetic resonance imaging were modeled with midpoint survival analyses, adjusted for PS‐quintile. Results A total of 741 children began therapy before 18 years, 197 with newer and 544 with injectable DMTs. Those started on newer DMTs were older (15.2 vs injectable 14.4 years, p = 0.001) and less likely to have a monofocal presentation. In PS‐quintile–adjusted analysis, those on newer DMTs had a lower relapse rate than those on injectables (rate ratio = 0.45, 95% confidence interval (CI) = 0.29–0.70, p < 0.001; rate difference = 0.27, 95% CI = 0.14–0.40, p = 0.004). One would need to treat with newer rather than injectable DMTs for 3.7 person‐years to prevent 1 relapse. Those started on newer DMTs had a lower rate of new/enlarging T2 (hazard ratio [HR] = 0.51, 95% CI = 0.36–0.72, p < 0.001) and gadolinium‐enhancing lesions (HR = 0.38, 95% CI = 0.23–0.63, p < 0.001) than those on injectables. Interpretation Initial treatment of pediatric MS/CIS with newer DMTs led to better disease activity control compared to injectables, supporting greater effectiveness of newer therapies. Long‐term safety data for newer DMTs are required. ANN NEUROL 2020 ANN NEUROL 2020;88:42–55

ObjectiveTo characterize the use and safety of newer disease-modifying therapies (DMTs) in children with multiple sclerosis (MS) and clinically isolated syndrome (CIS) treated under 18 years of age.MethodsThis is a cohort study including children with MS or CIS followed at 12 outpatient practices participating in the US Network of Pediatric MS Centers. DMT use, including duration, dose, and side effects, was analyzed. Newer DMTs were defined as agents receiving Food and Drug Administration approval or with increased use in adult MS after 2005.ResultsAs of July 2017, 1,019 pediatric patients with MS (n = 748) or CIS (n = 271) were enrolled (65% female, mean onset 13.0 ± 3.9 years, mean follow-up 3.5 ± 3.1 years, median 1.6 visits per year). Of these, 78% (n = 587) with MS and 11% (n = 31) with CIS received DMT before 18 years of age. This consisted of at least one newer DMT in 42%, including dimethyl fumarate (n = 102), natalizumab (n = 101), rituximab (n = 57), fingolimod (n = 37), daclizumab (n = 5), and teriflunomide (n = 3). Among 17%, the initial DMT prescribed was a newer agent (36 dimethyl fumarate, 30 natalizumab, 22 rituximab, 14 fingolimod, 2 teriflunomide). Over the last 10 years, the use of newer agents has increased, particularly in those ≥12 years and to lesser extent in those <12 years. The short-term side effect profiles of newer DMTs did not differ from those reported in adults.ConclusionNewer DMTs are often used in pediatric MS, and have similar short-term safety, tolerability, and side effect profiles as in adults. These findings may help inform pediatric MS management.

Cesarean delivery and maternal health during pregnancy may influence risk for pediatric-onset MS. We report a new possible association of pesticide-related environmental exposures with pediatric MS that warrants further investigation and replication.

Background: Cognitive impairment occurs in approximately one-third of pediatric-onset multiple sclerosis (POMS) patients. The Symbol Digit Modalities Test (SDMT), a widely used cognitive screen in adults, has yet to be incorporated early into the standard care of POMS. Objective: To screen for cognitive impairment early in the course of POMS and analyze predictive factors. Methods: Of the 955 POMS or clinically isolated syndrome (CIS) patients prospectively assessed from March 2014 to July 2018, 500 POMS and 116 CIS patients met inclusion criteria (disease onset before the age of 18, one or more SDMTs, and 8 years or older at the time of testing). Those with relapse were analyzed separately from those who were relapse-free. Results: At initial assessment, the mean (interquartile range (IQR)) age at symptom onset was 13.5 years (12.0, 15.9) and the mean (±SD) disease duration was 3.0 ± 2.9 years. Impaired processing speed occurred in 23.4% of POMS and in 16.4% of CIS. On serial testing ( n = 383, mean follow-up: 1.8 years), 14.1% had clinically meaningful decline predicted by older age of multiple sclerosis (MS) onset and male gender. Disease relapse or steroid use led to transient worsening on the SDMT. Conclusion: Early in the disease, some POMS and CIS patients are at risk for cognitive impairment and subsequent decline.

Pediatric MS cases may be less likely to consume sufficient iron compared to controls, and this warrants broader study to characterize a temporal relationship. No other significant difference in intake of most dietary factors was found.