Understanding Clinical Trials for Adults

What is a Clinical Trial?

Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. Clinical trials produce the best data available for health care decision making.

The purpose of clinical trials is research, so the studies follow strict scientific standards. These standards protect patients and help produce reliable study results.

The treatment being investigated in a clinical trial can be a medicinal product, a procedure, a device or another type of therapeutic intervention.

Clinical trials are an essential part of the process of evidenced based practice and can help guide treatment decisions for both health care professionals and patients.

Clinical trials are an important part of the pathway by which new medicinal products can obtain a licence from MHRA and become available for use as a new treatment in patients.

What are the stages of a clinical trial?

Phase Purpose Time
Preclinical Assess safety and biological activity in the laboratory and in animal models. 3- 6 years
Phase 1 Determine which dose is safe and how often he treatment should be given via which route. Few particpants numbers 1-2 years
Phase 2 Evaluate effectiveness of the treatment with larger numbers of parctipants and access to side effects and tolerance. 2-4 years
Phase 3 Determine whether the new treatment works better than an alternative current standard treatment. 5-8 years
Post Clinical Trial review Follow participants still taking the treatment to monitor side effects and 2-5 years

How do clinical trials determine if the treatment will work?

To be considered successful, phase 2 and 3 clinical trials have to show effectiveness in treating Duchenne. Each trial will select a primary endpoint, an aspect of Duchenne that can be measured and compared. For example, one endpoint might be peak expiratory flow, the amount of air you can breathe out in one go. This shows the strength of an individual’s breathing muscles. In order to be considered effective, the treatment being studied must improve the endpoints being studied when compared to no treatment or a placebo. Often trials will look at multiple endpoints.

Sometimes people appear to benefit from a treatment that doesn’t work, simply because they think and hope it will work. This is known as the placebo effect. Clinical trials often give some of the participants a placebo, a substance or treatment (often a sugar tablet or saline injection) that doesn’t do anything. This is to make sure that the real treatment works better than the placebo effect.

How are adults being involved in clinical trials?

The majority of trials for new treatments for Duchenne are restricted to children. This is due to a number of factors, such as:

  • Many trial endpoints can only be measured in people who can walk. An example that is often used is the six minute walk test, which measures how far a person can walk in six minutes. It is often chosen because it is well known and has been well studied.
  • Some trial endpoints (e.g. muscle biopsies) are easier to measure in children with Duchenne under 18 because they are stronger and have more muscle than adults with Duchenne.
  • Trials may be considered easier to administer for children, particularly where regular hospital visits may be required.
  • Some companies believe that treating children before they lose strength and the ability to walk is more important than treating adults, as it can show a larger benefit.

Adults may not be able to be involved in many trials, but increasingly trials on respiratory and cardiac treatments are focusing on adults. Some companies may also try to expand their trials to older age groups as they get into the later stages of development.

Regulators such as the EMA will usually only allow treatments to be used on the same age group as has been involved in the clinical trial. This is because there is a lack of evidence that the treatment will also work for adults. That means many treatments being developed will not be available to adults unless an adult trial is conducted.

This is why it is important that adults can be involved in clinical trials. DMD Pathfinders is currently working with Duchenne UK to encourage pharmaceutical companies to include adults in clinical trials.

Will there ever be a cure for adults?

Unfortunately some muscle cells cannot be replaced once they are lost. Most treatments therefore aim to prevent muscle loss before it occurs. There is currently no treatment at the clinical trial stage that could replace lost muscle. We continue to hope that this will be developed in future. In the near future, treatments may be made available which can slow down the progression of Duchenne and perhaps even restore some strength in the short term, but will not fully restore what has been lost.

How do you find out about Duchenne clinical trial opportunities?

You can search for information on all DMD clinical trials by visiting the DMD Hub website: Clinical Trial Finder.

You can also visit Clinicaltrials.gov run by the National Institute of Health in the USA,  and search for ‘Duchenne Muscular Dystrophy’.

The World Health Organisation’s International Clinical Trials Registry Platform (ICTRP), collects information from different registers to provide a central database of clinical trials.

The UK Clinical Trials Gateway is also helpful.

How do I get involved in a trial?

If there is a trial that you think might be suitable, contact the organisation running the trial, and find out which sites will be running the trial.

The mission of Duchenne UK’s DMD Hub is to ensure that all patients with DMD, including children and adults, have the opportunity to access clinical research opportunities.

Questions to ask before joining a clinical trial:

Each clinical trial is unique, with its own possible benefits and risks. Before you decide to take part in one, you may want answers to these questions:

  • Why is this study being done?
  • what is the age range of the trial?
  • What side effects might I expect from the study treatment? Are there other risks? (Keep in mind that there can also be side effects from standard treatments and from the disease itself.)
  • What kinds of treatments and tests would I need to have in this study? How often are they done?
    Some things to consider:
    – Treatments involving injection into the veins may require an access port to be fitted if your veins are difficult to find.
    – Muscle biopsies may require general anaesthetics in some cases.
    – Tests such as MRI scans will require you to transfer out of your wheelchair.
    – Some trials might require swallowing tablets.
  • Is there equipment available in clinics for adults (e.g. hoist/Hoyer lift for transfers)
  • How often will I need to attend a clinic to participate in the study? Will I be required to stay overnight?
  • How much time or travel is involved?
  • Will my family have to pay for anything? Will travel and accommodation cost be paid up front or claimed back for?
  • How could the study treatment affect my daily life?
  • Who will I contact if I have problems, questions, or concerns?
  • What are my other options (standard treatments, other studies)? What are their pros and cons?
  • What were the results in earlier studies of this treatment? How likely are they to apply to me?
  • How long will I be in the study? How long will the study last?
  • Are there reasons I would be removed from the study? Are there reasons the study might be stopped early?
  • Is long-term follow-up care part of the study? What would it involve?
  • If the treatment is working for me, can I keep getting it even after the study ends?
  • Can I talk to other patients already taking part in the study?
  • Will I be able to find out about the results of the study?
  • How long do I have to make this decision?