Clinical Trials

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Innovative treatments are tested in clinical trials.

Learn more about Clinical Trials

What is a clinical trial?

A clinical trial is a research study conducted with patients to evaluate whether a new treatment is safe (safety) and whether it works (efficacy). Clinical trials are performed to test the efficacy of drugs but also non-drug treatments such as radiotherapy or surgery and combinations of different treatments.

Why test new treatments?

When researchers think that they have found a promising treatment they do not immediately treat patients with it. If it is a brand new treatment, they will first test it in the laboratory, usually on tumor cells. If results in the laboratory are encouraging, they will test the treatment on animals. These studies are highly regulated to avoid unethical tests on animals. If results of the tests on animals are encouraging, researchers will set up, together with doctors, the first step of the experimentation of the new treatment on humans. This first step in humans is called a phase I clinical trial. Phase II and phase III clinical trials will follow if results are encouraging during the previous step. Thus, the risk for participants is higher in phase I than in phase II, and risks of a phase II trial will be higher than in phase III.
Sometimes, the treatment tested is not new, but the way it is given, the dosage or the combination with other treatments differ. It may also be a treatment already used for one type of condition. Before using it for another type of condition, however, a new study has to be done to see whether the treatment is safe and works for the new type of condition.

What are the main possible benefits of participating in clinical trials?

– Participants have access to a promising treatment which is not available elsewhere
– The new treatment may have a higher efficacy than the standard treatment
– Participants will be watched carefully by health professionals according to a protocol
– The clinical trial is an experiment and its results will be helpful for all. It will either allow other patients to benefit from a new and useful treatment or avoid researchers to continue their research on a useless or harmful treatment. The results will also help researchers to understand a disease better.

What are the main possible risks of participating in clinical trials?

– The new treatment may not have any added value
– The new treatment may have some side-effects that can range from minor and reversible side-effects to life-threatening side-effects. Some side-effects can also appear weeks, months or even years later and include damages to important organs such as heart or kidney or the development of a second condition or disease
– In phase III clinical trials you usually do not know if you receive the new treatment or not.

How can I participate?

Your doctor proposes it to you. Sometimes, doctors will propose you to participate in a clinical trial. You have the right to accept or refuse without any consequence on the quality of your treatment.
You tell your doctor that you want some help to find a clinical trial for you. If your doctor does not propose any clinical trial but you really want to participate, the best way is to ask your doctor if there is any clinical trial for your type of condition implemented near your home or in your country. Clinical trials are registered and your doctor might know how to look for clinical trials. You can also ask your doctor on the possibilities of participating in a clinical trial in another country if none is available in your country. The possibilities of doing so vary from one country to another. Feel free to contact your health insurance, patients’ organizations or any other support to make it possible if this is important for you.
You search yourself for a clinical trial. You can also search for a clinical trial yourself. To enter in a clinical trial, there are criteria to be fulfilled like age, gender, condition type or previous treatments.

What are my rights as a patient?

Before considering entering in a clinical trial, each patient has to be fully informed about the trial. This is done through the informed consent. This procedure will explain everything the patient needs to know : purpose of the trial, sponsor, tests, how long will it last, etc. Taking part in a clinical trial is the decision of the patient only. Each patient can talk with his doctor for further information. The patient has the right to withdraw from a trial at any time, for any reason.

What are clinical trial phases?

Clinical trials are conducted in a series of steps, called phases – each phase is designed to answer a separate research question.

Phase I

Phase 1 trials aims to determine the safety of a new medication. Usually the medication is given to a few healthy volunteers (usually about 20 to 80 people) and the trial can last for several months. In addition to its safety, this phase also aims to investigate the most appropriate dosage which can be given without any serious side effects and the ideal way for the medication to be administered, for example orally or intravenously.

Phase II

During phase 2 studies which can last from several months to 2 years, the new medication is given to a larger group of people (usually between 50 and 300 participants) who have the condition or disease for which the medication is being developed. The primary aim for this trial phase is to determine the effectiveness of the medication. More information on the dosage and side effects is also gathered during this phase. Results from phase II studies provides the background for designing the methods for Phase III studies


Phase III

Phase III trials are carried out in a much larger population, typically involving between 300 to 3000 participants for a period of 1 to 4 years. This phase aims to determine the effect of the new medication in a specific population. Here the new medication is compared to the “standard of care treatment” (i.e. the current treatment for the disease/condition which is being investigated)  or a placebo (i.e. a substance that has no therapeutic effect) to ascertain if it is more effective and has less side effects. For this purpose, phase III trials are usually “randomized”, meaning the group of patients chosen to receive either the new medication or standard treatment/placebo happens by chance. It is also common to have these studies double-blinded, which means that neither the participant nor the investigator knows which medication the participant is taking.

Phase IV

Phase IV trials are conducted after the new medication has been approved by the Food and Drug Administration (FDA) or the European Medicine Agency (EMA). This is carried on thousands of volunteers who have the disease condition. Phase IV trials focuses provide more information about the side effects and the safety of the medication, the long-lasting effects and how well the medication works when used extensively in a wider population.

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