Learn about clinical trials, and what you need to consider before taking part in a trial.
What are the different phases of a clinical trial?
Some clinical trials may cover two of these phases, for example ‘phase 1/2’ trials, which aim to identify the highest safe dose, and also how well that dose works.
Phase 1
Aims to assess the safety of a treatment. Phase 1 trials involve a small number of people, who are often healthy volunteers. The researchers adjust the dose 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 it has been tested in people who have the condition that the treatment is intending to treat.
The researchers may divide participants into groups – for example, one group 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 3
Often called the ‘confirmatory’ phase, phase 3 trials aim 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, and/or placebo control. These trials take much longer than phase 1 or 2 trials, and are also much larger, often involving people from across the world.
Phase 4
Also known as ‘post-marketing surveillance’, these studies may take place after the treatment has been approved for use in routine healthcare (for example on the NHS). These studies give information about the long-term benefits and risks of the treatment in a much larger group of people, many of whom may also be receiving treatment for other conditions. This helps to identify the risks and benefits in a ‘real world’ situation.
More information
Each clinical trial has strict criteria for who can take part. These criteria may include age, gender, the type and stage of a condition, previous treatment history, and other medical conditions.
Factors that allow someone to take part in a clinical trial are called ‘inclusion criteria’, while those that disallow someone from participating are called ‘exclusion criteria’.
Inclusion and exclusion criteria are not used to reject people personally, instead they:
- Keep the participants safe; for example, another underlying condition could make taking part in the trial dangerous.
- Increase the reliability of the results by ensuring that everyone taking part has similar symptoms at the beginning of the trial. Otherwise, it could be difficult for the researchers to interpret the results, because they might not know if the reason one person responded to treatment, and another didn’t is due to the drug or due to differences in their condition to begin with.
In most circumstances, people taking part in a clinical trial will find it easier if they live near the research team conducting the trial, because they might need to be monitored frequently. You can ask the clinical trial team if you will be reimbursed for travel costs.
People have different reasons for taking part in clinical trials. Some would like the opportunity to potentially benefit from new treatments before they become more widely available (although it is not guaranteed that you will receive a treatment that will directly benefit you).
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. (Please note, you should still attend your normal healthcare appointments even if you are taking part in a clinical trial.)
Other people may feel that by taking part, they are ‘doing their bit’ to advance science and help others in the future. Clinical trials may not only help to accelerate the development of new treatments but could also improve our knowledge of muscle wasting conditions.
Many people with muscle wasting and weakening conditions 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 can involve multiple and frequent visits to hospital. This is not always easy or practical and can have an impact on the whole family.
The procedures in the trial could be painful, for example injections and biopsies. Treatments being tested in the study may cause side-effects.
The treatment you receive might not provide any direct benefit for you; depending on the trial, there is a chance you might be given a very low dose of the drug or a placebo (an inactive version of the drug).
In addition, taking part in one clinical trial may affect your chances of taking part in another one in the future. If this is a concern, you should discuss with members of your healthcare team before agreeing to take part.
You should find out as much as possible about the clinical trial before enrolling, by asking the members of the healthcare team questions about it.
Below is a list of questions you may like to ask members of your healthcare team and the clinical trial team before agreeing to take part:
- What is the purpose of the study?
- Who is going to be taking part in the study?
- Why do researchers believe the experimental treatment being tested may be effective?
- Has it been tested before?
- What exactly will I have to do? 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 I need to stay in hospital?
- How often will I need to visit the hospital for tests?
- Can any tests be done at home?
- 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?
- 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 is the trial being monitored?
- How will I know if the experimental treatment is working?
- Will results of the trial be provided to me?
- Who will be in charge of my care?
- Would I be allowed to take part in other trials in the future?
Before agreeing to take part, there are several features you should look out for in official clinical trials:
- Registered: Official clinical trials will be registered at ClinicalTrials.gov, which provides information about the trial, and who is in charge of it.
- Informed consent: Researchers must outline a ‘protocol’ that clearly states their research questions and intentions. After reading and understanding this protocol, participants will sign an ‘informed consent’ document to show that they have been provided enough information of exactly what will be involved, and the risks and benefits of taking part. You do need to sign the informed consent document to take part in the study, but it is not a contract – you are allowed to drop out of the study at any time. In case of children and minors, they should give an ‘informed assent’ along with the consent from their parents or guardians.
- Monitoring and review: Official clinical studies must be reviewed, approved, and monitored by an Institutional Review Board of doctors, 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 have data monitoring committees that 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. Constant monitoring of the trial ensures your health and safety is a priority.
- Involvement of healthcare providers: Participating in a clinical study will not obstruct your usual care – you should continue to attend your usual medical appointments. Your specialist neuromuscular consultant will make sure that taking part in the study will not conflict with your current treatments and medications. This is why it is important to discuss your participation with them before, during, and after the trial.
- Eligibility criteria: Official clinical trials will provide strict criteria on who can and cannot take part 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 take part. These are 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 not be legitimate is if the team asks you to pay to take part. Official clinical studies will not ask for any payment and will often reimburse you for extra costs that you paid to take part (for example travel expenses).
Take part in a clinical trial
To find clinical trials we recommend joining a patient registry for your specific condition if one is available. Patient registries are databases that inform members about clinical trials and other research studies.
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.
For other conditions, use the Antidote clinical trials tracker to find out about relevant clinical trials that are recruiting near you.
If your condition is not listed on Antidote or you have any questions about trials you find, please email our research team on research@musculardystrophyuk.org.
Other ways to get involved in research
If you can’t find the right clinical trial for you, there are still lots of other ways to help with research.
Community research hub
Our community research hub provides opportunities for you to engage with research surveys, focus groups observational studies and more… Your participation enables essential research, contributes to our collective understanding, and can lead to real-world impact. Share your experiences and help change the future.
Lay Research Panel
Volunteer on our Lay Research Panel. Work closely with our Research Team to evaluate applications for our research grants. Our panel is made up entirely of people affected by muscle wasting or weakening conditions.