What is a clinical trial? 

To be approved for use, all treatments must be shown that they work and that they are safe for humans. Once a promising treatment has been identified in a laboratory setting, researchers run clinical trials. Clinical trials help researchers test the safety and effectiveness of new treatments. They also allow researchers to compare new potential treatments with the current treatments that are available. 

Clinical trials rely on the participation of volunteers. Some studies will recruit volunteers with no health conditions, and others will need people who have the condition that the drug aims to treat. 

Each trial will have its own set of criteria for participating. This may include location, age, gender, length of time since diagnosis, severity of reaction to gluten and other medical conditions. Not everyone is eligible to take part in every trial. 

What research happens before a clinical trial? 

The first stage of treatment development is to understand the disease process and identify a target. It can take years of research and laboratory work to produce a potential treatment that can be tested in humans. Sometimes a treatment that has already been licensed for one condition can be tested as a potential treatment for another condition, by looking at any benefits and any side effects in the context of another condition. 

Phases of a clinical trial 

For new treatments to be approved and licensed for medical use, they must go through a series of trial phases: 

• Phase I: The treatment is studied for the first time in a small group of volunteers (10-50) to see how the body processes it and to check for side effects and find a safe dosage (amount). 
• Phase II: The treatment is tested in a larger group of volunteers (50-100, sometimes over 100), typically people who have the condition that the treatment is targeting. This phase looks at how well the treatment works for those with the condition and investigates any side effects.   
• Phase III: The treatment is tested in an even larger group of people (hundreds or thousands) to assess how effective the new treatment is compared to existing treatments or a placebo. A placebo is a ‘dummy’ treatment which looks like the ‘real’ treatment being tested but contains no active treatment. Once the treatment shows promise and is considered safe in hundreds or thousands of people, it can be licensed for medical use. 
• Phase IV: This involves following people over a series of years to see how the drug performs in the long term, once it has been licensed for medical use 

In total, it can take 10-15 years to develop, test and license a new treatment. 

Regulation of clinical trials 

Standards for clinical trials are set nationally and internationally. In the UK, a government agency called the Medicines and Healthcare products Regulatory Agency (MHRA) has to review and authorise a clinical trial of a new medicine before it can begin. All medical research involving people in the UK has to be approved by an independent research ethics committee. The Association of the British Pharmaceutical Industry (ABPI) code of practice covers clinical trials, working closely with the government and the NHS to ensure that patients come first. 

Blinding in clinical trials  

In a clinical trial a volunteer may be given a new treatment, a placebo (‘dummy’) treatment or an existing treatment and often neither the volunteer or the investigator will know what has been given. This is called carrying out the study ‘blind’ and is to prevent the results being affected by bias (knowledge and an expectation to react in a certain way). 

Clinical trials for coeliac disease 

There are more drug trials in coeliac disease happening now than ever before. Phase 2 studies of treatments that modify the autoimmune reaction to gluten, treatments that break down gluten, and others that might help the body tolerate gluten, are starting to produce results. Larazotide, the only treatment tested in a Phase 3 study, sadly didn’t work well enough in treating coeliac disease. However, more treatments should enter Phase 3 trials in the coming years and we’re hopeful that some of these may prove effective. 

Clinical trials exploring new treatments for coeliac disease will most likely involve eating gluten for a short period of time to cause an immune response. Consuming gluten for a short time during a trial may make participants feel unwell but it’s unlikely to cause lasting damage. 

Anyone considering taking part in a clinical trial should not be afraid to ask questions of the researchers and to ensure that all of their questions have been fully answered to their satisfaction before consenting to take part. 

If you sign up to take part in a clinical trial, you can choose to stop taking part in the trial at any point without giving a reason. 

Participation in a clinical trial is voluntary and Coeliac UK neither promotes participation or non-participation, it is an individual’s decision. Where there is an opportunity to take part in a clinical trial related to a treatment for coeliac disease, Coeliac UK will share relevant information so that the community remains well informed and knows where to go to access further information or contact a member of the trial team. 

Further general information on clinical trials can be found on the NHS Choices website.