What Should Patients and Caregivers Know About DMD Clinical Trial Eligibility?

Introduction

Duchenne muscular dystrophy (DMD) is a rare muscle disease caused by changes (mutations) in the gene that produces dystrophin, a protein that helps muscle cells remain intact and function properly. Without enough dystrophin, muscles become damaged and weaker over time. DMD affects roughly 1 in 3,500 to 5,000 male births¹. There is currently no cure for DMD. Researchers are studying investigational approaches in clinical trials to better understand their safety and effectiveness.

Who can join DMD clinical trials depends on each study’s requirements. Common criteria include a confirmed diagnosis, genetic mutation, past and current treatments, age, disease stage, and overall health. Meeting a trial’s initial requirements does not guarantee a spot; the trial site makes the final decision after a full screening process.

DMD clinical trial eligibility can sometimes be hard to understand, leaving those living with the condition, their parents, caregivers, and loved ones with many questions. This blog will walk you through how eligibility works, what the screening process is like, how sites decide if someone qualifies, and potential next steps to take. The aim is to prepare you for your trial search and for conversations with your care team.

Key takeaways

• DMD clinical trial teams decide eligibility by checking each person against the trial’s inclusion and exclusion criteria.

• Knowing your or your child’s genetic information matters because some DMD therapies are designed only for specific mutations or changes affecting certain parts of the gene.

• Previous or current treatments can form part of a trial’s eligibility criteria and are assessed by the clinical trial team.

• Clinical trial teams also consider age, disease stage, and overall health.

• The screening process usually has three steps: pre-screening, screening at the trial site, and a final eligibility decision.

• If someone isn’t eligible for a DMD clinical trial, they may have other trial options.

• Your care team can help you understand which eligibility criteria may apply. A myTomorrows patient navigator can also help you explore your options.

Inderstanding the DMD clinical trial eligibility process

Who decides if someone is eligible for a DMD clinical trial?

A clinical trial team checks a person’s medical history and test results against the trial’s inclusion and exclusion criteria. This team often includes doctors, nurses, study coordinators, social workers, and other trained staff.

The role of inclusion and exclusion criteria

Inclusion criteria are the requirements a person must have to join a trial. Exclusion criteria are the factors that would prevent them from taking part. Someone may be excluded for safety reasons or because the treatment is unlikely to work for them. Both types of criteria also help keep the study group similar so that results can be compared more reliably. Learn more about inclusion and exclusion criteria here.

What are the most common eligibility criteria for a DMD clinical trial?

Common eligibility criteria for DMD trials include:

• Confirmed diagnosis of DMD

• Genetic information

• Previous and current treatments

• Age

• Disease stage

• Overall health

The following sections will explain these criteria in more detail. There’s a lot to consider, but you don’t have to figure all this out on your own. Your doctor, care team, or a myTomorrows patient navigator can help you understand how these criteria apply to your situation.

Diagnosis and treatment history

Is a confirmed DMD diagnosis needed?

Yes. Most DMD trials require a confirmed diagnosis, which genetic testing can provide.

Why is it important to know the genetic information?

Genetic testing, in addition to confirming a DMD diagnosis, can also reveal your or your child’s genetic mutation and which part of the gene is affected. This matters because some DMD trials are designed only for specific mutations in certain parts of the gene. If a person’s genetic information does not match the trial’s eligibility criteria, they may not be eligible for that particular trial. The trial site confirms eligibility.

Knowing the mutation is important for these types of therapies²:

• Exon skipping – An approach that “skips” a section of the dystrophin gene so the body can make a shorter, partially working version of the protein.

• Gene replacement therapy – An approach that uses a modified virus (often an adeno-associated virus, or AAV) to deliver a shortened version of the dystrophin gene. Some people with certain mutations are excluded from this therapy for safety reasons.

• Stop-codon read-through – An approach that helps the body ignore a false “stop” signal, caused by certain mutations, that ends dystrophin production early.

• Gene editing – An approach, still in early stages, that aims to fix or remove the part of the dystrophin gene that has the mutation. CRISPR-Cas9 is a well-known example of a gene editing technology.

Not all DMD trials require a specific genetic mutation. Some test treatments that aren’t tied to a mutation, such as those that aim to promote muscle repair or reduce inflammation. Others focus on preserving heart and lung function.

If you or your child hasn’t had a genetic test, your care team may be able to help you get one.

Do previous or current treatments affect DMD clinical trial eligibility?

Potentially, yes. Trial teams consider past treatments because these may be relevant to the trial’s safety requirements and eligibility criteria.

For example, a person who has already had a DMD gene therapy involving an adeno-associated virus (AAV) is often excluded from other gene therapy trials. The first therapy can lead the body to make antibodies, which may affect eligibility for another gene therapy trial.

Clinical trial teams also look at whether someone has been in another trial recently. If so, they may have to wait weeks or months before joining a new one.

Current treatments can matter, too. For example, some trials require stopping certain DMD treatments, such as exon-skipping therapies, for a specified time before starting the study treatment. This is called a washout period, which allows the earlier treatment to clear out of the body so the two don’t interact. Other trials may require someone who takes corticosteroids to be on a stable dose for a set period before joining.

Trial teams also look at medicines taken for other conditions, as these can change how the study treatment works or cause side effects.

Other factor trial teams evaluate

Is there an age limit for DMD clinical trials?

Most DMD clinical trials set an age range in their eligibility criteria, but the range varies by trial. A group of similar age also makes results more comparable.

Many trials seek participants who are younger or just starting to show symptoms. For example, gene replacement and exon-skipping therapies aim to protect muscle strength or slow its loss. Earlier in the disease, children have more muscle strength, so these trials can show more clearly whether a treatment helps. Starting treatment young may also give researchers more time to see how it affects children as they grow up.

Because many trials seek younger participants, age can limit eligibility options for older children, teens, and adults. That said, if someone is outside a trial’s age range, other trials may still be open to them. Some trials have no upper age limit, and others are designed for adults or older, non-ambulatory participants (no longer able to walk).

Do you have to be ambulatory to join a DMD clinical trial?

No, but it depends on the trial and its aim.

Many trials require that someone be ambulatory (able to walk). In these trials, researchers compare how a person walks at the start (known as a baseline) with how they walk at later visits. They also use timed tests, such as climbing stairs or rising from the floor. Other measures include scored assessments of everyday movements, such as the North Star Ambulatory Assessment (NSAA). By comparing results across visits, researchers look to see if the weakness continues, slows down, levels off, or potentially even improves.

Those who can’t walk or who can’t perform these movements may still qualify for other DMD clinical trials. Instead, researchers may assess study outcomes over time by looking at changes in:

• Heart health

• Breathing capacity

• Upper limb function, using assessments such as the Performance of Upper Limb (PUL) scale

• How much muscle has been replaced by fat or scar tissue (fibrosis)

• Markers in the blood (biomarkers)

In some cases, treatments first studied in ambulatory patients may later be studied in non-ambulatory patients.

How overall health affects DMD clinical trial eligibility

Trial teams consider a person’s overall health when deciding who can take part. The goal is to make sure someone is well enough to receive the treatment safely and can take part until the end of the trial.

Trial teams may look at:

• Any signs of heart muscle damage (cardiomyopathy)

• Breathing capacity and lung function

• Liver and kidney function

What happens after finding a potentially relevant DMD clinical trial

Finding a DMD trial that may be relevant to you or your child is important, but it’s just the first step.

If you choose to pursue a clinical trial, researchers will still need to confirm whether you or your child meets the eligibility criteria. Before starting the screening process, your care team or a myTomorrows patient navigator can help you prepare. Patient navigators review your situation, help you organize medical information, and connect you with trial sites.

The role of a myTomorrows patient navigator and how they can help

A myTomorrows patient navigator is a specialist with a medical background who can support individuals and families to find and explore their clinical trial options. They can help you and your family understand which DMD trials may be relevant and explain eligibility criteria in clear language. This is a free service, and you can book a call with a patient navigator at a time that suits you best, in the language of your choice.

They can:

• Use the information you share to search for potentially relevant clinical trials and provide a trial search overview

• Explain what taking part in a clinical trial may involve

• Refer and connect you with a trial site

Patient navigators do not replace your doctor or care team and cannot provide any medical advice.

What is the eligibility process like for a DMD clinical trial?

There are three steps to this process:

1. Pre-screening – This is a first review of basic details about your or your child’s DMD diagnosis. It may cover medical history, genetic information, past and current treatments, age, disease stage, and overall health. Preparing this information ahead of time can save time during the review.

This step can often be done over the phone with your doctor, care team, trial team, or with a patient navigator if you choose to use one. If a trial appears potentially relevant based on the information available, they can help connect you with the trial site, which determines eligibility.

2. Screening – This step usually takes place at the trial’s study site and is more detailed than the pre-screening.

Before screening tests begin, the trial team will explain what the trial involves and answer your questions. You are then asked to sign an informed consent form (ICF), which shows you understand the study and agree to move forward with screening. Depending on the age of the participant, the parent or legal guardian may be the one to sign. Children who are old enough to understand may also be asked to sign what’s called an assent form, which explains the study in simpler language, to show they’re willing to take part.

Once the forms are signed, the clinical trial team reviews medical history and performs the exams and tests needed to decide eligibility. Depending on the trial, this may include a physical exam, functional assessment, lab work, heart tests such as an electrocardiogram (ECG), and imaging tests such as an MRI.

Screening may involve one or more visits and take several weeks, depending on the trial. These assessments allow the clinical trial team to determine whether the participant meets the study’s eligibility requirements.

3. Final eligibility decision – After screening is complete, the clinical trial team will decide if you or your child can join. The decision mainly depends on screening test results, but other factors, such as whether the trial still has spots available, may also be considered.

If the answer is no, it doesn’t mean you did anything wrong.

What happens if someone is eligible for a DMD clinical trial?

If eligible for a DMD clinical trial and there is a spot available, your care team or a patient navigator can support you with your decision and help you understand what joining involves.

Being eligible doesn’t mean you have to join, however. There is no obligation to say yes, and you can withdraw from the trial at any time.

What happens if someone is not eligible for a DMD clinical trial?

If someone is not eligible for a DMD clinical trial, there are several possible reasons, which could include:

• The trial is full

• Genetic test results don’t meet the trial’s requirements

• Previous treatments ruled them out

• Their age is outside the trial’s range

• Disease stage or walking ability doesn’t match trial requirements

• Screening results didn’t meet trial requirements

• Other health conditions may make the trial unsafe or hard to complete

Whatever the reason, this news can be disappointing, but you may still have other options available.

Some points to consider:

• Each trial is different. Not qualifying for one doesn’t mean you won’t qualify for another

• Some trials aren’t tied to a specific mutation and are open to people at different stages of the disease

• Trials sometimes expand who can join over time, for example, by adding non-ambulatory patients later on

• Your eligibility can change after you stop a previous treatment with your doctor’s guidance and enough time passes

• New DMD trials may open up in the future

• Approved therapies may be available

While clinical trials may be an option for some people, they are not the only way investigational treatments may be accessed. In some cases, a treating physician may consider an expanded access program, a strictly regulated pathway that only physicians can request.

If you or your child isn’t eligible for a trial, speaking with your doctor, care team, or a patient navigator can help you understand your options.

Frequently asked questions

Can someone be in more than one clinical trial at once?

Usually not, if both trials are testing a treatment. Clinical trial teams often don’t allow it, as the treatments could interact, and it would be hard to tell which one caused any effects, either good or bad. However, someone may be able to take part in both a clinical trial and a natural history study, which tracks how a disease changes over time.

Does someone have to pay to take part in a DMD clinical trial?

There is no fee to join a clinical trial, but taking part may involve other costs, such as travel, meals, and lodging. Some trials help pay expenses related to the trial, but not all costs may be covered.

Before deciding whether to join a trial, ask the trial team what is and isn’t covered, what may be billed to your insurance, and whether you must pay any expenses up front that would be reimbursed later.

Can someone join a DMD clinical trial in another country?

It’s possible, but it depends on the trial. Some trials are open to people in other countries, and they may help cover travel, meals, and lodging, but this support varies. Other trials are open only to people in the country where the trial is held.