Clinical trials & medical research

Why do we have clinical trials in children and young people?

Clinical trials are research studies involving people. They test whether particular treatments are safe and how well they work. We need to know: Does a treatment work? Does it work better than other treatments? Does it have any side effects? Clinical trials are designed to answer these questions to improve the health and quality of life for patients, including children. Until well-designed trials have been carried out, we simply do not have enough evidence to know if a treatment is both effective and safe. Without trials, there is a risk that people will be given treatments which do not work and which may be harmful. 

Experimenting and testing have long been a part of medicine, and there are many different types of trial. (See below for an explanation of Phase 1, Phase 2, Phase 3, and randomised controlled trials.) Randomised controlled trials are generally recognised as the most reliable way to compare different approaches to preventing and treating illness. They can be used to compare drugs and other types of treatment across a range of conditions. 

Dr William van’t Hoff is Co-Director of the Medicines for Children Research Network. William talks about the importance of clinical trials in children and young people, the different phases of research, and the ethics of conducting research involving children.

Children and young people may need different treatments from adults because they are at a different stage of development. Clinical trials in children are therefore essential to ensure they receive appropriate, safe and effective treatments and care. There are guidelines to protect children who take part in clinical trials of medicines in the UK and throughout the European Union (EU).

Phase 1 and Phase 2 trials
Clinical trials are carried out in a number of stages, or phases. When a new treatment is developed, such as a new cancer drug, it will be tried first in a few people to get an idea of how safe it is. They may be healthy volunteers, who are given a compensation payment for taking part, or they may be people who are ill, perhaps people who have already tried all the usual treatments. This is called a Phase 1 trial. At this stage the treatment is usually given to all those taking part and is not being compared against some other treatment.

At Phase 2 the researchers will know more about the treatment. The aim of a Phase 2 trial is to test the new treatment, such as a drug, in a larger group of people to better measure safety and side effects and see if there are signs of positive effects in patients. A Phase 2 trial may or may not involve comparison with another treatment. However, the numbers of people included are still too small to give firm evidence of whether the treatment works or that any change is not just happening by chance. This is why Phase 3 trials are needed.

Robert aged 22 was diagnosed with cystic fibrosis at birth and from early childhood has always taken part in clinical trials. 

Phase 3, randomised trials
Phase 3 trials are usually large. They include hundreds or even thousands of patients. They often compare the effects of new treatments or drugs with standard treatments, if there are any. They provide more reliable evidence about whether newer treatments are better, or worse than existing treatments, and firmer evidence about how common and serious any short term side effects are. Almost all Phase 3 trials are randomised trials. In a randomised trial, some people are given the new treatment; others are given an existing, standard treatment. If there is no standard treatment, the new treatment may be compared with a placebo. Some randomised trials may compare more than two groups and some may be blind (see below). 

A placebo is a treatment, with no active ingredient, which is designed to appear very like the treatment being tested. By comparing people’s responses to the placebo and to the treatment being tested, researchers can tell whether the treatment is having any real benefit, rather than patients simply feeling better because ‘something is being done’.

(Sometimes you may hear the new treatment group called the ‘experimental group’, ‘trial group’ or ‘intervention group’. This can be confusing, as all the groups, including the control group, are part of the trial, and people in the control group may also be given an intervention, in the form of the standard treatment or placebo.)

There are several ways in which the results of trials can be made as reliable and accurate as possible. One of these is to make the trial a ‘blind trial’. In a blind trial the participants are not told which group they are in. This is because if they knew which treatment they were getting it might influence how they felt or reported their symptoms. Some trials are double-blind, which means that neither participants nor the doctors and others treating them know which people are getting which treatments. This also avoids the doctors’ hopes and expectations influencing the results of the trial.

Ryan aged 12, has polyarthritis and is taking part in a randomised placebo controlled drug trial. Unlike Robert who has taken part in many clinical trials, this is Ryan’s first trial.

Clinical trials are carried out when we do not know whether a treatment works or which treatment works best. Sometimes evidence from a trial shows we can stop giving people a treatment which does not work or it can prove a new treatment is worth taking. 

Sophie (aged 23) was diagnosed with cystic fibrosis at the age of 8. She says it is important that young people understand how clinical research can improve people’s life expectancy and quality of life. 

The majority of young people we talked to said clinical trials in young people were a good thing. Alexander, however, has mixed feelings about young people taking part in clinical trials. 

There were a few young people that were unsure what a clinical trial is and unsure why clinical trials are necessary in young people. 

Stephanie, aged 18, has Wegener’s granulomatosis, a rare condition in young people that involves inflammation of the small and medium blood vessels and can affect many organs in the body. When she was 15, Stephanie took part in a drug trial that involved quite intensive treatment that was similar to chemotherapy. She says that taking part in a clinical trial when you are younger helps you to understand what is involved and prepares you for future trials if they are offered. However, like Mohini, she found it difficult to explain to others what a clinical trial is and what the treatment involves. She found it easier not to tell them she was in a clinical trial and to say that she was having chemotherapy treatment as everyone seemed to understand this.

Last reviewed March 2017.
Last updated July 2014.


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