Child navigating clinical trials maze, guided by hope and medical advancements.

Navigating Pediatric Multiple Sclerosis: Hope and Hurdles in Clinical Trials

Avery Sinclair in Health & Wellness December 2025 • 5 min read.

"Why pediatric MS trials are crucial for our youngest patients and how we can overcome the unique challenges they present."

For years, treatments for children with multiple sclerosis (MS) were based on studies done in adults. This meant kids were often given medications “off-label,” without knowing the true effects on their developing bodies. Thankfully, new laws are changing this, requiring pediatric studies for new medications. This shift is crucial for ensuring our children receive the safest and most effective care possible.

The push for pediatric MS trials is especially important now, as new oral and intravenous medications emerge. These treatments could be easier for children to tolerate than the older, injectable drugs. But to make sure these new therapies are truly safe and effective, we need well-designed clinical trials that consider the unique aspects of pediatric MS.

As we begin to design these trials, several challenges arise: How do we find enough participants, given that pediatric MS is rare? How do we measure success in a way that’s meaningful for children? And how do we address the very real concerns about the long-term effects of these medications on a child’s developing immune, reproductive, and nervous systems? Let’s take a closer look at the current state of pediatric MS trials and the challenges we face.

Why are Pediatric MS Clinical Trials Necessary?

Child navigating clinical trials maze, guided by hope and medical advancements.

The need for pediatric MS clinical trials is underscored by recent legislation in the United States and mandates from regulatory bodies like the Federal Drug Authority and the European Medicines Agency. These regulations now require pediatric investigation plans (PIPs) that include Phase III pediatric studies for any new medication. This requirement is particularly relevant for emerging MS therapies, highlighting a shift towards ensuring that children are not overlooked in medical advancements.

Despite the fact that 3-5% of all MS patients experience their first symptoms in childhood or adolescence, pediatric MS remains a rare condition. This rarity presents significant challenges to the implementation of clinical trials. A recent position paper by the International Pediatric Multiple Sclerosis Study Group (IPMSSG) has addressed additional challenges, including determining appropriate study endpoints, designing effective studies, and addressing concerns about the impact of new agents on the maturing immune, reproductive, and central nervous systems of young patients.

Limited Patient Population: The low incidence of pediatric-onset MS, estimated between 0.18-0.51/100,000 per year, makes enrolling an adequate number of patients for clinical trials challenging.
Multicenter Collaboration: Success depends on multicenter international support and consensus definitions for diagnosing MS to ensure consistent patient enrollment across different locations.
Study Endpoints and Design: Trials must be designed with appropriate endpoints to yield informative results, given the limited group of potential study participants. The IPMSSG suggests using time to next relapse or annualized relapse rate as primary outcomes in phase III clinical trials, as these metrics easily translate to clinical practice.

In anticipation of pediatric clinical trials, Verhey et al. conducted a study to estimate the sample sizes needed for pediatric studies, using both clinical and radiologic metrics. The study used prospective data from a national study of children and adolescents followed from their incident demyelinating attack, generating sample size estimates using outcomes of time to next relapse and annualized relapse rate (ARR) for placebo-controlled trials of 12 and 24 months' duration. The researchers found that a sample size of between 75 and 115 patients per arm would be required to detect a 40% treatment effect over placebo in a two-year study using ARR as a primary outcome. This is less than the sample sizes required for similar studies in the adult population, potentially because of the higher relapse rate seen in the early stages of MS in patients with pediatric onset.

The Future of Pediatric MS Treatment

Despite the challenges in designing and recruiting patients for pediatric MS clinical trials, the collection of safety information, pharmacokinetics, and efficacy data specific to pediatric patients is vital. Data from initial clinical trials in the pediatric population will inform the efficacy and safety of the therapy under study and the feasibility of pediatric MS trials and outcomes. A thoughtful approach to clinical trial design is required, and the choice of agents to study will require discussion among leaders at various MS centers worldwide. With this approach, therapeutics with new mechanisms of action and improved tolerability may become realistic treatment options for pediatric patients with MS.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.4172/2168-975x.1000117, Alternate LINK

Title: Clinical Trials In Pediatric Multiple Sclerosis: Pending Landscape And Challenges

Subject: General Medicine

Journal: Brain Disorders & Therapy

Publisher: OMICS Publishing Group

Authors: Brenda Banwell

Published: 2014-01-01

Everything You Need To Know

Why are pediatric MS clinical trials so important for children?

Pediatric MS clinical trials are essential because they ensure that children with Multiple Sclerosis receive the safest and most effective treatments. Historically, children were often treated with medications "off-label," meaning the drugs were not specifically studied or approved for them. New regulations from the Federal Drug Authority and the European Medicines Agency mandate Phase III pediatric studies for new medications, which are crucial for tailoring treatments and strategies to the well-being of young patients. These trials allow researchers to understand how new therapies, such as oral and intravenous medications, impact the developing immune, reproductive, and nervous systems of children, leading to better healthcare outcomes.

What are the main challenges in conducting pediatric MS clinical trials?

Several challenges make pediatric MS clinical trials complex. Firstly, the rarity of pediatric-onset MS, affecting 3-5% of all MS patients, makes it difficult to find enough participants. Secondly, designing effective studies with appropriate endpoints is a key hurdle. The International Pediatric Multiple Sclerosis Study Group (IPMSSG) suggests using time to next relapse or annualized relapse rate as primary outcomes, which can translate easily into clinical practice. Finally, ensuring multicenter international support and consensus definitions for diagnosing MS are crucial for consistent patient enrollment across different locations.

How do new regulations impact the treatment of pediatric MS?

Recent legislation in the United States and mandates from regulatory bodies significantly impact the treatment of pediatric MS. The regulations, like those from the Federal Drug Authority and the European Medicines Agency, now require pediatric investigation plans (PIPs) that include Phase III pediatric studies for any new medication. This ensures that children are not overlooked in medical advancements and receive treatments specifically studied and designed for their needs. This shift is particularly relevant for emerging MS therapies and could mean that new, potentially better-tolerated medications become available for children.

What study design aspects are crucial for pediatric MS clinical trials, and why?

Well-designed clinical trials must consider unique aspects of pediatric MS. Given the limited number of potential study participants, trials must use appropriate endpoints to yield informative results. The IPMSSG recommends using time to next relapse or annualized relapse rate as primary outcomes. These metrics easily translate to clinical practice. Moreover, multicenter international collaboration and consensus on MS diagnosis definitions are essential for ensuring consistent patient enrollment across different locations. The study by Verhey et al. highlights the importance of determining appropriate sample sizes using clinical and radiologic metrics, showing that smaller sample sizes might be sufficient in pediatric studies due to higher relapse rates.

What is the future of pediatric MS treatment based on current clinical trial efforts?

The future of pediatric MS treatment looks promising, driven by ongoing clinical trial efforts. Collecting safety information, pharmacokinetics, and efficacy data specific to pediatric patients is vital. Data from these trials will inform the efficacy and safety of new therapies. A thoughtful approach to clinical trial design is required, and selecting agents to study will involve collaboration among leaders at various MS centers worldwide. This collaborative, data-driven approach aims to develop therapeutics with new mechanisms of action and improved tolerability, which could become realistic treatment options for pediatric patients with MS, ultimately improving their quality of life and managing the challenges associated with the disease.