Skip to content

Clinical trials

Clinical studies cover any form of research involving people.

This includes observational studies, to understand more about a muscle wasting condition and how it progresses (its natural history), and clinical trials, to assess the safety and effectiveness of specific interventions. These interventions could be medical products, for example, drugs or devices; medical procedures, such as a type of surgery; or changes to a person’s lifestyle, such as an exercise regime.

As with any experiment, researchers design clinical trials to answer specific research questions. After reviewing what is already known about the drug or intervention, from preclinical studies or previous trials, researchers will develop a specific plan or protocol, outlining:

  • who can take part (eligibility criteria – often called inclusion and exclusion criteria)
  • how many people are needed at each stage to ensure robust data collection
  • how long the study will last
  • whether or not there will be a control group (to limit bias)
  • how the treatment will be administered and at what dosage
  • what will be measured (outcome measures) and when
  • how the data will be reviewed and analysed.

We’ve put together some frequently asked questions to help you understand the process of clinical trials. If you have further questions, please contact the Research Line at

What are the different phases of a clinical trial?

Clinical trials typically follow a series of stages, or phases:

  • Phase 1
    Aims to assess the safety of a treatment. Phase 1 trials involve a small number of people, who are often healthy volunteers. However, in the case of genetic therapies, these trials are carried out in people with the condition. The researchers adjust dosing schemes based on preclinical data from animals, to find out how much of a treatment the body can tolerate and what its potential side-effects are.
  • Phase 2
    Aims to assess the safety and effectiveness of a treatment. This may be the first time of testing it in people who have the condition that the treatment is intending to treat. Researchers may divide participants into groups – one of which will receive the optimal dose, the other of which will receive a different dose or a placebo (an inactive substance designed to resemble the treatment being tested).
    Phase 2 trials are sometimes divided into phase 2a and phase 2b. Phase 2a is specifically designed to determine the best dose of the drug. Phase 2b is specifically designed to study how well the drug works at the dose determined in the phase 2a study.
  • Phase 3
    Often referred to as the ‘confirmatory’ phase, phase 3 aims to prove the effectiveness of a treatment in people with the condition. Researchers will usually compare the new treatment against the current standard treatment (if one exists). These trials not only take much longer than phase 1 or 2 trials, but are also much larger, often involving people from multiple centres across the world.
  • Phase 4
    Also known as ‘post-marketing surveillance’, these studies may take place after the regulatory authorities have approved the treatment. They give information about the long-term risks and benefits of the treatment in a much larger patient population, many of whom may also be receiving treatment for other conditions. This helps to identify the risks and benefits in a ‘real world’ situation.

Some clinical trials may fall in two of these phases. For example, you may see phase 1/2 trials, which aims to identify the highest safe dose, and also how well that dose works.

Why participate in a clinical trial?

People have different reasons. Some would like the opportunity to potentially benefit from new treatments before they become more widely available. However it’s important to remember that there are risks with taking part (see below). In addition, some trials are designed with a placebo arm, which means that some participants don’t actually receive the treatment being tested.

Another potential advantage is that people taking part in clinical trials are often followed up regularly and are closely monitored, even after the trial has finished. This close attention could result in better management of the condition.

Other people may feel that by taking part, they are ‘doing their bit’ to advance science and potentially help others in future. Participating in a clinical trial may not only help to accelerate the development of new treatments but could also improve our knowledge of muscle wasting conditions.

What are the risks and disadvantages of taking part in a trial?

Many people are understandably eager to take part in clinical trials. However it is very important to understand exactly what is involved in a particular trial and the potential risks associated with a new treatment. You should discuss the study in detail with the trial nurse or doctor before giving consent to take part.

A potential disadvantage is that studies often involve multiple and frequent visits to hospital. This is not always easy or practical and can have an impact on the whole family. Procedures could be painful, for example injections and biopsies and, of course, there is always the risk of an adverse reaction to the treatment.

Participants in a trial also have to keep in mind that the treatment they receive might not provide any direct benefit for them – there is a chance they might be given a very low dose of the drug, or even a placebo. In addition, participants should be aware that taking part in one clinical trial may affect their chances of taking part in a future clinical trial. This should be discussed with members of your healthcare team prior to enrollment.

Who can participate in a clinical trial?

All clinical trials have guidelines about who can take part. The factors that allow someone to participate in a clinical trial are called ‘inclusion criteria’ and those that disallow someone from participating are called ‘exclusion criteria’. These criteria are based on such factors as age, gender, the type and stage of a condition, previous treatment history, and other medical conditions. Before joining a clinical trial, a participant must qualify for the study.

Inclusion and exclusion criteria are not used to reject people personally, instead they:

  • Keep the participants safe, for example another underlying condition could make participation in the trial dangerous.
  • Help ensure that the researchers are able to produce reliable results and therefore get the treatment to market as quickly as possible so that the wider population can benefit.
  • Increase the reliability of the results by ensuring that everyone taking part has similar symptoms at the beginning of the trial. Otherwise it is difficult for the researchers to interpret the results because they won’t know if the reason one patient responded to treatment and another didn’t is due to the drug or differences in their condition to begin with. This is especially helpful in the early phases of a clinical trial when there are only few participants.

In most circumstances, people who wish to participate in a clinical trial will find it easier if they live relatively near the team of people who are conducting the research, because they need to be monitored frequently. Some studies provide financial support for travel costs; you can ask the clinical trial team if these resources are available.

What do I need to know before I enrol in a clinical trial?

You should know as much as possible about the clinical trial and feel comfortable asking the members of the healthcare team questions about it.

Deciding to enrol into a clinical trial can be daunting process. Muscular Dystrophy UK is here to support you through this sometimes tough decision making process. We believe you should know as much as possible about a clinical trial and feel comfortable in asking the members of the healthcare team questions about it. The following questions might be helpful for the participant to discuss with the healthcare team:

  • What is the purpose of the study?
  • Who is going to be in the study?
  • Why do researchers believe the experimental treatment being tested may be effective?
  • Has it been tested before?
  • What kinds of tests and experimental treatments are involved?
  • How do the possible risks, side effects, and benefits in the study compare with my current treatment?
  • How might this trial affect my daily life?
  • How long will the trial last?
  • Will hospitalisation be required?
  • Who will pay for the experimental treatment?
  • Will I be reimbursed for other expenses?
  • What type of long-term follow up care is part of this study?
  • How will I know that the experimental treatment is working?
  • Will results of the trials be provided to me?
  • Who will be in charge of my care?
  • Would I be allowed to participate in future trials?
What do I do if I want to participate in a clinical trial?

For more information about participating in a clinical trial, please visit our patient registries page.

Find clinical trials
MDUK recommends joining a patient registry for your specific condition, if one is available. Patient registries will inform participants about clinical trials and other research studies quickly and efficiently, and also provide an opportunity for you to share information about how your condition affects your life. This data can also be used to support clinical trial feasibility and planning, improve understanding of the natural history and prevalence of specific diseases, and understand and improve standards of care.

Learn more about neuromuscular patient registries for UK patients. If you don’t live in the UK, or your condition is not listed, TREAT-NMD has a global list of registries here.

For people living with Duchenne muscular dystrophy, DMD Hub Clinical Trial Finder provides accurate and up to date information regarding clinical trials in the UK.

If your condition is not listed, use the Antidote clinical trials tracker  to find out about relevant clinical trials that are recruiting near you.

f you have any questions about a particular trial, or would like to know more about research into your condition, please contact our Research Line on 020 7803 4813 or at

We are aware that some muscle wasting conditions cannot be recognised by the Antidote clinical trial finder. We are working closely with Antidote to address this and further develop the tool. If your condition is not recognised, or you have questions about any trials you find, please contact us directly.

Is Muscular Dystrophy UK funding any clinical studies?

We are also funding several observational studies, including the largest natural history study for Duchenne muscular dystrophy, named NorthStar.

In the past we have funded a clinical trial to test a new drug for people with McArdle’s disease as well as a clinical trial that looked into the long-term benefit of Vitamin C for people with Charcot-Marie-Tooth disease.

In addition to the studies funded directly through our research programme, we provide administrative and managerial support for the setting up of clinical trials. These include clinical trial co-ordinators, who help with the setting up and running of clinical studies at a particular centre. They are responsible for ensuring that the research takes place within regulatory guidelines as well as the specifications outlined in the trial protocol. Muscular Dystrophy UK currently funds clinical trial co-ordinators at the muscle centres in Newcastle, London and Oxford.

Guidelines for official clinical trial studies
There are constantly new clinical trials happening that are important to developing new neuromuscular treatments. A wide range of research goes into a clinical trial, such as safety assessments and reviews of the effectiveness of treatments, whether they be medical products (drugs or devices), procedures (surgeries), or behavioural changes to daily life (a new exercise to understand clinical trial processes and results, and how/where you can participate).

We appreciate the significant toll a neuromuscular condition can have on you and some people have a strong desire to participate in any research that can give people access to new treatments as soon as possible. However, it can be dangerous to roll out new treatments without regulators, pharmaceutical companies and the NHS to do their due diligence to ensure you benefit from the right, new treatment for you. Participating in a clinical trial is the key to helping others access such treatments safely.

It is essential that you are informed of the strict criteria that has been put in place to protect you should you choose to participate. It is important that you know exactly what is involved in any trial and any potential risks associated with participating, and that you only participate in trials that are officially registered to ensure that your health and safety are protected. Not every trial may be right for you and participating in trials that are not legitimate may put your health and safety at risk, as they may not have the same safety guidelines outlined below.

Guidelines for Official Clinical Studies

Informed Consent: To perform an official clinical study, medical researchers must outline a ‘protocol’ that clearly states their research questions and intentions. After reading and comprehending this protocol, patients will sign an ‘Informed Consent’ document to show that they have been provided sufficient information of exactly what will be involved, and the risks and benefits of participating. It is common to include other activities to measure a patient’s understanding before allowing them to consent to participate so that they are completely informed. It is important to note that signing an informed consent document is required to participate in the study to protect your health and safety, but it is NOT a contract and participants are allowed to drop out at any time.

Monitoring and Review: Official clinical studies must be reviewed, approved, and monitored by an Institutional Review Board of doctors, medical researchers, and other community members. The board will ensure that you are protected, the study is ethical, and risks are minimised. Some clinical studies may also be monitored by data monitoring committees, which monitor the safety and scientific integrity of the trial, and have the power to stop the trial if it is harming participants or is not effective. Should you choose to participate in a clinical trial, you should understand that the trial is constantly being monitored, and your health and safety is a priority.

Involvement of Healthcare Providers: Participating in a clinical study will not impede your usual care. Typically, patients continue to see their usual medical appointments. Your specialist neuromuscular consultant will make sure that participating in the study will not conflict with your current treatments and medications, which is why it is important to discuss your participation with them before, during, and after the trial.

Identifying Potential Participants: Official clinical trials will provide strict criteria on who can participate in the trial. The research team is often looking for a specific group of people and will ensure that only people who fit these characteristics participate. This is called the eligibility criteria and will be outlined in the protocol, along with the reasons for targeting this group of people.

Funding: A red flag that a study may be unofficial is if the team asks you to pay any amount to participate. Official clinical studies will not ask for any payment, and will often reimburse you for your participation and any extra costs that you endured.

We understand the eagerness to participate in clinical trials, but it is important that you are fully aware of these guidelines and why they are put in place. Official clinical studies must fulfil numerous requirements to ensure that participants are protected and that the trial can achieve its scientific purpose.

All official clinical trials have to be registered, and you can check what trials are currently going on here

If there is a trial you are interested in, speak to your neuromuscular consultant, who can advise you on whether you are suitable for the trial and help ensure that your health and safety will be protected. Please see below for a list of questions you may want to ask your consultant or the trial research team to see if a trial is right for you.

Questions to Ask When Considering Participating in a Clinical Trial

  • Is the trial officially registered at
  • What are the possible interventions that I might receive? How will they be determined (i.e. by chance)? Will I know which I am receiving?
  • What exactly will I have to do? Are tests and procedures involved? How often will I have to visit the hospital/clinic?
  • How do the risks, side effects, and benefits compare with those of my current treatment?
  • How is the trial being monitored?
  • Who will oversee my medical care while I am participating?
  • After the trial: Will I receive the results? Will I be reimbursed? Is there any long-term follow-up care involved?