Real-world treatment in pediatric-onset multiple sclerosis: Data from the Swiss pediatric inflammatory brain disease cohort study.

INTRODUCTION

Pediatric-onset multiple sclerosis (POMS) exhibits more aggressive inflammation than adult-onset multiple sclerosis, with higher relapse rates, faster lesion accrual, earlier disability progression, and a greater risk of cognitive impairment. Appropriate treatment is crucial to minimize lifelong impairment.

METHODS

This multicenter, observational cohort study examined patients from the Swiss Pediatric Inflammatory Brain Disease Registry with POMS who received index treatment with disease-modifying therapies (DMTs) of varying efficacy: mild-efficacy therapy (MET), intermediate-efficacy therapy (IET), and high-efficacy therapy (HET). We analyzed demographic and baseline characteristics, index treatment type, reasons for switching, breakthrough disease activity, and pre- and post-treatment annualized relapse rates before and after index treatment start. We further studied index treatment prescription development over time. Descriptive statistics were used.

RESULTS

Of 41 patients with POMS, 32 (78%) were female. Thirty-nine received disease-modifying treatment post-diagnosis: 15 started MET, 13 IET, and 11 HET. Discontinuation was highest with MET (67%), followed by IET (54%), and HET (18%). Side effects prompted switching in the MET group, while disease activity drove switching in IET and HET groups. Mean annualized relapse rates decreased after index treatment from 1.07 to 0.43 with MET, from 1.17 to 0.33 with IET, and from 1.73 to 0.09 with HET. After 2019, MET was discontinued as index treatment.

DISCUSSION: POMS treatment has evolved; since 2019, only IET and HET have been used in this Swiss cohort, achieving ARR reductions and lower discontinuation rates compared to MET.