What is a clinical trial?
Published 14 Jan 2021 • By Candice Salomé
Clinical trials aim at improving patient care and treatment, at every stage of the disease. Clinical trials can help assess the efficiency and tolerance of new treatments before offering them to the patients suffering from a given pathology.
So what are the different phases of a clinical trial? How are they legally regulated? Why participate in a clinical trial and how?
Let us tell you everything!
A clinical trial (also called clinical study) is a study performed on voluntary patients as part of the development of a treatment. The aim can be to assess the efficacy and safety of a new treatment, the absorption speed of a new molecule, its adverse effects or even its mode of operation.
How are clinical trials run?
Clinical trials cannot start before they receive the approval of a Research Ethics Committee and from the Medicines and Healthcare Products Regulatory Agency (MHRA).
Patients must give their informed consent* to participate in a trial.
A clinical trial will take place following 4 distinct and successive phases. Each stage of the study leads to a different trial:
- Phase 1: the trials of this first phase aim at assessing the safety of the treatment, to make sure it is harmless. This first phase is usually performed on a small group of healthy individuals.
- Phase 2: these trials assess the efficacy of the treatment on dozens of patients, allowing to determine the appropriate dose.
- Phase 3: these trials allow comparing the new treatment to another medicine usually used or to a placebo. This third phase is carried out on a large number of patients. Patients are divided into two random groups (randomized trial). One group will try out the new treatment and the other group will try out the placebo. After this phase, conclusive results can lead to a marketing authorisation.
- Phase 4: these trials assess the long-term effects of the treatment. A treatment that has obtained a marketing authorisation remains under surveillance of the sanitary authorities.
Clinical studies can be double-blind. This means that neither the patient nor the doctor know if the patient is receiving the new treatment or the placebo. When the doctor knows but the patient doesn't, it is a single-blind trial. These blind trials allow reducing the psychological effect of the treatment.
*In health law, an informed consent means that the doctor must clearly present to the patient the risks of a therapeutic conduct.
How are clinical trials legally regulated?
Clinical trials performed on the human person must fulfil a number of ethical and organisational criteria to guarantee the participants' safety. These criteria are regulated by law. This allows protecting the people concerned by the clinical study, whether they are underage, a protected adult, an adult, a healthy, sick or vulnerable volunteer.
Indeed, the interest of the individual is more important than the interests of science and society.
Clinical trials must be directed by an investigator (a registered doctor) or by people who are qualified to work in the field of research (midwife, dentist...).
The investigator must:
- inform the patients on the objective of the research, the methodology, the expected benefits, the potential adverse effects, the right to refuse the participation as well as the right to withdraw from the trial at any moment.
- gather the informed consent of people willing to participate in the study in writing, and make sure that these people understand the given information.
In addition, all participants must be registered by the trial sponsor* in the national file of healthy people or whose pathology has no relation to the treatment of the study.
Finally, the trial sponsor must purchase an insurance allowing patients to be compensated in the event of potential consequences.
* The sponsor is the natural or legal person who took the initiative to start a clinical trial. It can be a pharmaceutical laboratory, a service provider, an association, a care centre, or a natural person (a doctor for example).
Why participate in clinical trials?
Without clinical trials, no new therapeutic method or new treatment can be created. Each year, thousands of citizens enter clinical trials to test new treatments.
Entering a clinical trial is voluntary, and everyone can potentially participate.
However, each clinical trial has inclusion and exclusion criteria. For example, the first phase of a clinical trial is carried out on healthy individuals. A disease or a certain medical history might be an exclusion criterion.
Additionally, the age, gender, type and stage of the disease can also be inclusion or exclusion criteria.
These criteria guarantee the homogeneity of the groups and therefore reliable and relevant results.
Anyone can be contacted to participate in a clinical trial. This invitation can be made during a medical appointment, through posters or media announcements. You can also volunteer independently and contact organisations working in clinical research.
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