Time to Revisit the Treatment Approach in Kids With MS?

COPENHAGEN, Denmark — Growing evidence supports the use of highly effective disease-modifying therapies for children with multiple sclerosis (MS). However, only few of these medications are licensed for pediatric use, indicating it may be time to reconsider the standard treatment approach for this patient population.

Treatments for pediatric-onset MS have mostly been used off-label until the recent approvals of fingolimod, dimethyl fumarate, and teriflunomide. Typically, children with MS start with moderately effective therapies, while more potent options are reserved for those who don’t respond.

However, recent research suggests this may not be the most effective treatment strategy for this patient population. Several studies suggesting impressive treatment responses to highly effective therapies (HETs) in children were presented at the Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) 2024.

In one study, initiating monoclonal antibody treatment during childhood was associated with reduced disability into early adulthood and beyond.

“Our findings are a strong argument for rethinking current treatment guidelines,” said study investigator Sifat Sharmin, PhD, The University of Melbourne, Melbourne, Australia.

“By allowing earlier access to highly effective treatments, we can significantly enhance the quality of life for children with MS and reduce the burden of long-term disability,” she added.

In another presentation, Yael Hacohen, MD, Great Ormond Street Hospital, London, England, noted that the use of these more effective monoclonal antibody therapies in children with MS has been associated with some improvements in Expanded Disability Status Scale (EDSS) scores after 2 or 3 years of treatment.

Maybe this is a sign that “this is a population that can repair, in contrast to adult patients,” she wondered.

MS is primarily a disease of adults, but pediatric MS accounts for up to 5% of all cases. Children with MS tend to have much more active disease than adults, Hacohen explained. However, they also tend to recover from attacks more quickly with little disability, which sometimes causes diagnostic delays.

A pediatrician or family doctor will often dismiss pins and needles or blurred vision that only lasts a couple of days and won’t send the patient for an MRI, she said. But on MRI, pediatric patients with MS often have multiple lesions, even though they may have had very few symptoms. The EDSS may not change very much, but there can still be significant brain atrophy.

Over the past 20 years, there’s been an explosion of new disease-modifying treatments for MS, but these high-efficacy treatments, such as antibody therapies, are often not prescribed until the patient reaches the age of 18 years, both Sharmin and Hacohen pointed out.

“We need to get some of these medications approved for use in children,” Hacohen said.

Slowed Disability

In her presentation, Sharmin reported an observational study that included 282 patients younger than 18 years at MS onset identified from the French MS Registry, the Italian MS Register, and the Global MSBase Registry.

Of these, 110 (39%) had initiated therapy with ocrelizumab, rituximab, or natalizumab early in the disease course between ages 12 and 17 years and 172 (61%) had initiated treatment with one of these agents at ages 20-22 years.

The primary outcome was the difference in EDSS scores from baseline (at age 18 years) to ages 23-27 years between those who had started treatment with one of these agents early and those who had started late.

At the baseline of age 18 years, the median EDSS score was 1.5 in the early group and 1.3 in the late group. Median follow-up time was 10.8 years.

The data were adjusted for baseline differences in factors such as sex, age at symptom onset, time from onset to clinically definite MS, and the number of relapses (using inverse probability treatment weighting based on propensity scores).

Results showed that between ages 23 and 27 years, disability was a 0.57 step lower in the early group than in the late group. The mean absolute differences in EDSS from baseline were 0.40 in the early group and 0.95 in the late group. This benefit of early treatment persisted throughout the rest of the follow-up period.

The substantially lower risk of progressing to higher disability levels in the early treatment group was particularly evident in the moderate disability range, where further progression was reduced by up to 97%, Sharmin noted.

“Starting these highly effective therapies, before the onset of significant neurological impairments, appears crucial for preserving neurological function in children with relapsing-remitting MS over the long term,” she said.

These findings highlight the critical importance of early intervention in pediatric-onset MS, she concluded.

The researchers are planning further work to generate more evidence to support the proactive treatment of pediatric-onset MS, with a particular focus on assessing the long-term risks for immunosuppressive therapies in this population.

Ocrelizumab Experience in Children

Hacohen reported on a UK cohort of children with MS treated with ocrelizumab, with 66 patients having more than 12 months of follow-up. Of these, only four patients had relapses, and there was no evidence of disease activity in 94% patients.

“We’ve stopped doing relapse clinic because they really don’t relapse,” Hacohen reported.

“This has completely changed our practice in pediatric MS,” she said. Twice a year, patients come in to have pre-infusion bloods and clinical assessments and then return a month later for treatment.

“They only have to come to the hospital for 4 days a year, and the rest of the time, they can forget they have MS,” said Hacohen.

In terms of complications, one patient in the UK cohort developed enterovirus meningitis but recovered completely, and two patients had hypogammaglobulinemia and were changed to an extended interval or to a different agent.

Hacohen cautioned that hypogammaglobulinemia — a condition in which immunoglobulin levels are below normal — is “something that hypothetically we should maybe be more worried about in the pediatric population, particularly as these patients are more likely to be on anti-CD20 therapies for a much longer time.”

She said this complication tends to happen after about 4 or 5 years of treatment. “If we start seeing IgG levels dropping, we need to come up with a plan about extending the dosing interval. We need clinical trials to look at this.”

Hacohen also drew attention to the issue of vaccinations not being effective in patients on anti-CD20 antibody therapy, which could be a particular problem in children.

However, given that vaccinations do seem to be effective in patients taking natalizumab, pediatric patients with highly active disease could receive the drug for 3-6 months while receiving vaccines and then switched over to ocrelizumab, she said.

Giving natalizumab for such a short period is not believed to have a high risk of developing JCV antibodies, she added.

In another presentation, Brenda Banwell, MD, Johns Hopkins Children’s Center, Baltimore, reported new data from an early study (OPERETTA 1) with ocrelizumab in pediatric relapsing-remitting MS showing a safety profile similar to that observed in adults. The suggested dose is 300 mg for children under 35 kg and 600 mg for adults over 35 kg, administered every 24 weeks. These doses will be further investigated in the ongoing phase III OPERETTA 2 trial.

Sharmin received a postdoctoral fellowship from MS Australia. The OPERETTA studies were sponsored by F. Hoffmann-La Roche. Banwell served as a consultant to Roche. Hacohen reported no relevant disclosures.