What is a clinical trial?
Published 14 Jan 2021 • By Candice Salomé
Clinical trials aim to improve the care and treatment of patients at all stages of their health condition. Clinical trials can help assess the efficacy and tolerance of new treatments before offering them to patients affected by a particular illness.
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 carried out on voluntary patients as part of the development of a treatment. Its objective may be to assess the efficacy and safety of a new treatment, the absorption speed of a new molecule, its side effects or even its mode of action.
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 clinical trial.
A clinical trial takes place following 4 distinct and successive phases. Each stage of the study leads to a different trial:
- Phase 1: the trials in this first phase aim to measure the safety of the treatment, to make sure that it is risk-free. This first phase is generally carried out 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 compare the new treatment to commonly used drug or to a placebo. This third phase involves a larger number of patients. Patients are divided into two groups at random (randomised 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 health 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. If the doctor knows which treatment is being used but not the patient, it is a single-blind trial. These blind trials reduce the psychological effect of the treatment.
*In health law, an informed consent implies that the doctor must clearly present all the risks of therapeutic conduct to the patient.
How are clinical trials legally regulated?
Clinical trials performed on human beings must meet several ethical and organisational criteria to guarantee participants' safety. These criteria are regulated by law. This makes it possible to protect the subjects of the clinical trial, whether they are a minor, a vulnerable adult, an adult, a healthy, sick or vulnerable volunteer. Indeed, the interest of the individual must take precedence over the interests of science and society.
Clinical trials must be conducted under the direction of an investigator (a registered doctor) or by people who are qualified to work in the field of research (midwife, dentist, etc.).
The investigator must:
- Inform the patients about the purpose of the research, its methodology, expected benefits, potential adverse effects, the right to refuse to participate in the trial and the right to withdraw from the trial at any time.
- Obtained the written informed consent from those who agree to participate in the trial and ensure that they have fully understood the information given.
In addition, all participants must be registered by the trial sponsor* in the national file of healthy persons or persons whose health condition is unrelated to the treatment under study.
Finally, the trial sponsor is required to take out insurance allowing patients to be compensated in the event of potential consequences.
* The sponsor is the individual or entity who takes the initiative for the clinical trial. It can be a pharmaceutical laboratory, a service provider, a charitable organisation, a health care institution, or a private individual (a doctor, for example).
How and why participate in a clinical trial?
Without clinical trials, no new therapeutic method or new treatment can be developed. Thus, each year thousands of citizens enter clinical trials to test new treatments.
Clinical trials are on a voluntary basis, and anyone can potentially take part.
However, each clinical trial has inclusion and exclusion criteria. For example, a Phase 1 clinical trial is conducted on healthy individuals. An illness or certain medical history may exclude a participant from this phase.
Additionally, age, gender, type and stage of the disease may also be inclusion or exclusion criteria.
These criteria ensure the homogeneity of the groups and therefore reliable and relevant results.
Anyone can be approached to participate in a clinical trial. This can take place at a doctor's appointment, through posters or media announcements. It is also possible to volunteer independently by contacting organisations dedicated to clinical research.
If you would like to take part in a clinical trial, here are a few sites where you can find ongoing studies recruiting volunteers, as well as more information on how to participate in studies (source: NHS):
- Be Part of Research
- WHO International Clinical Trials Registry Platform
- Versus Arthritis: Our current research
- Cancer Research UK: Find a clinical trial
- Multiple Sclerosis Society: Be in a study
- Target Ovarian Cancer: About clinical trials
- Parkinson's UK: Take part in research
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