Rituximab Suppresses Clinical Relapses, MRI Activity in Pediatric MS

Pediatric-onset multiple sclerosis (POMS) may be treated with rituximab in the future, as a study published in the Journal of Child Neurology recently found that rituximab was able to suppress clinical relapses and stabilize lesion burden in children with MS.¹ The findings could indicate rituximab as a first-line treatment for POMS.

Individuals who have symptom onset prior to the age of 18 years are considered to have POMS and account for 3% to 5% of all cases of MS across the world.² Children with MS can have cognitive issues due to inflammatory damage that occurs in their development period. Treatment options for POMS include B-cell depletion, which can be done with anti-CD20 monoclonal antibodies like rituximab.¹ This study aimed to assess how well a single-center cohort of children with POMS reacted to use of rituximab as a first-line chronic disease-modifying therapy (DMT).

The study was conducted at a large tertiary care children’s hospital in the US, and electronic medical records from patients treated between January 1, 2006, and December 31, 2023, were eligible for inclusion. Participants needed to have no prior exposure to other DMTs to be included in this study. POMS was established in the participants through clinical presentation and MRI findings.

Variables included age at formal diagnosis, age at first symptoms, and sex of the participant. Number of clinical attacks before the start of rituximab, lesion counts on a brain MRI at diagnosis, time from diagnosis to the first dose of rituximab, and cerebrospinal fluid oligoclonal band count were also variables in the study. Total duration of rituximab therapy and rituximab induction and maintenance regimens acted as treatment-related variables, with treatment duration defined as time from initiation through July 1, 2025, or last clinical follow-up. Doses of rituximab were typically 750 mg/m² per dose in 2 doses taken 2 weeks apart. The number of clinical relapses was collected as a data point for this study.

There were 51 patients identified who were living with POMS and initiated DMT; 17 received rituximab as a first-line DMT and were included in this study. Most of the participants were female participants (76.5%), and the median age at first symptoms and first diagnosis was 15 years. A total of 47.1% had reported 1 attack, 47.1% had reported 2 attacks, and 5.9% had reported 3 attacks before the start of rituximab.

A total of 16 of the 17 patients had cerebrospinal fluid data available, with all 16 having positive oligoclonal bands. The median (range) number of bands was 9.5 (3-17). The median number of T2 lesions was 26 (4-76) in the diagnostic brain MRI.

A median of 6 (2-42) weeks after diagnosis, rituximab was initiated in all of the patients, with 13 receiving the 750 mg/m² dose and 4 receiving the 375 mg/m² dose. All patients received a maintenance dose every 6 months, with patients receiving a median of 5 maintenance infusions after their induction. Median duration of rituximab treatment was 126 (4-281) weeks through the observation period.

A total of 1 patient experienced a clinical relapse within the first 6 months of treatment, but no clinical relapses were reported after rituximab was considered active. A single patient developed a new T2 lesion after rituximab was considered therapeutic, but the remaining patients did not report any lesion activity, with the median number of T2 lesions being 24 on the post-induction baseline MRI and 24 on the most recent MRI. A total of 10 patients had a decrease in total lesion count, 5 had stable lesion counts, and 2 had a higher lesion count.

There were some limitations to this study. There was no comparison group, and the study contained a small sample size. Efficacy according to the treatment line was not assessed in this study. Retrospective diagnostic classification was a limitation. Disability progression and cognitive outcomes were not included in the data set. There was a short duration of follow-up in several of the patients.

“In the context of emerging data favoring early initiation of high-efficacy therapies, rituximab represents a promising option for children diagnosed with MS and supports further prospective, multicenter studies,” the authors concluded.

References

1. Lewis H, Kiss A, Ramani P, et al. First-line rituximab in pediatric-onset multiple sclerosis: clinical and MRI outcomes in a retrospective cohort. J Child Neurol. Published online June 2, 2026. doi:10.1177/08830738261452770
2. Pediatric-onset multiple sclerosis. Cleveland Clinic. Accessed June 2, 2026. https://my.clevelandclinic.org/departments/neurological/depts/multiple-sclerosis/ms-approaches/pediatric-onset-multiple-sclerosis