What is a clinical trial?

Clinical trials help researchers test the safety and effectiveness of new treatments and compare them with current ones.

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.

What research happens before a clinical trial?

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

Phases of a clinical trial

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

• Phase I: The treatment is trialled for the first time on a small group of healthy volunteers to check for side effects and find a safe dosage.
• Phase II: The treatment is tested on a larger group of people who have the condition the treatment is targeting. It is usually compared against a placebo (non treatment).
• Phase III: This phase assess how effective the new treatment is and how it compares to existing treatments. The treatment is tested in hundreds or thousands of people and can then 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.

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

Regulation of clinical trials

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. 

Blinding in clinical trials 

If you take part in a trial you may be given a new treatment, placebo (non treatment) or an existing treatment and most often you and the investigator will not know which you have been given. This is called carrying out the study ‘blind’ and is to prevent the results being affected by knowledge and an expectation to react in a certain way.

What might be involved in a clinical trial for a treatment for coeliac disease?

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 investigators and to ensure these 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 chose 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.

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