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About clinical studies

This page contains comprehensible and reliable information about clinical studies. Click on the questions below for clear and concise answers.

Why are clinical studies important?

Those who participate in a clinical study, either as patients or as healthy volunteers, contribute to the advancement of medicine and a better future for patients.

Existing medications (drugs) can be either not suitable or not effective for many patients. That is why hundreds of thousands of scientists worldwide are conducting research on new drugs and treatments. However, these drugs cannot be marketed without first conducting clinical studies with healthy volunteers and patients. These clinical studies are conducted in order to find out the long-term safety, efficacy and effect of the medication. In addition, new medications or treatments are also compared to existing ones.

It is necessary that enough people participate in these studies so that scientifically substantiated conclusions can be drawn.

What is clinical research?

When a new medication is being developed, it must be proven that this new medication is safe and that it works before it can be marketed.

Development of medications is sub-divided into pre-clinical research within test tubes and animals on the one hand and clinical research with people on the other hand. Only after it has been proven that the new product is safe and effective in animal experiments, it can be studied in people.

The tests that are conducted in people in order to find out whether the new product is safe and effective are called clinical studies. These studies are conducted in a set of four consecutive phases (I, II, III and IV). The objective of a clinical study depends on the new product that is being investigated.

What are the phases of clinical research in people?

  1. Pre-clinical research within test tubes and animals
  2. Clinical research with people

Clinical research consists of strictly controlled clinical studies in 4 consecutive phases.

  1. Phase 1 studies – Is the drug safe?
    The potential new drug is usually administered to a small group (20 to 100) of healthy volunteers to study the general effects (distribution, metabolism and elimination, as well as any side effects) of the new drug. 
  2. Phase 2 studies – Does the drug work?
    If the results from the phase I study show that the potential new drug is safe, a phase II study is started in a small group of selected patients (100 to 500) who take part on a voluntary basis. During this phase, researchers investigate whether the new drug works for the illness for which it was developed. The patients who can take part are selected based on strict inclusion and exclusion criteria. This is done in order to minimise the variation within the group so that scientifically substantiated conclusions can be made.
  3. Phase 3 studies - Does the drug work better, just as well or less well than existing drugs or treatments? 
    The potential new drug is investigated in a larger group of patients (1,000 to 5,000) in order to study its long-term efficacy and safety. In this phase the drug is compared to existing drugs or treatments. If it is proven that the drug yields sufficient or better results and is safe, it officially receives marketing authorisation. From that moment on, the new drug is available on the market and can be prescribed by doctors. 
  4. Phase 4 studies – What are the long-term effects?
    The new drug’s safety continues to be monitored even after it has been launched on the market. During phase IV studies researchers primarily look at possible side effects that occur sporadically and at long-term complications. In addition, researchers sometimes investigate whether the drug is effective for other illnesses or disorders. 

Who conducts clinical studies?

There is a differentiation between (i) commercial studies and (ii) non-commercial or academic studies. The initiator of a commercial study is a pharmaceutical company or a company that manufactures medical devices. With an academic trial, the initiator is an investigator from a hospital.

Both types of studies must follow the same strict rules. Hence, in both cases a study subject is equally well-protected and has the same rights and obligations.

In commercial studies there is no direct contact between patients and the initiator. All contact goes through a participating study site and an investigator who is connected to the study. The investigator ensures that the subjects are supervised, followed-up and examined.

Who can take part in a clinical study?

Both healthy volunteers and patients can be involved in a study.

Every study has specific conditions, and these are always described in the study protocol. A clinical study’s protocol entails all of the study’s rules and procedures. This is the reference book or playbook, as it were, for correct conduct of a study. The protocol must always be approved by a medical ethics committee and by the respective government authorities before the study can start.

The conditions for participation are also called the inclusion and exclusion criteria

Possible participants:

  • must meet study-specific conditions;
  • are and have to be comprehensively informed based on the information form;
  • must understand what participation entails, including what the possible risks and benefits are;
  • must be able to take part entirely voluntarily, as explained in the information form;
  • must be insured against possible damage;
  • must be able to stop participating in the study at any time;
  • must consent and sign a document, known as the patient information and informed consent form, at the start of the study procedure.  

Is taking part in a clinical trial safe? Who guarantees this safety?

Clinical studies are very strictly regulated in order to keep the risk to participating subjects to a minimum. In order to protect the rights, integrity and confidentiality of study subjects as well as the credibility of the study data, the international ethical and scientific conditions are specified in the Declaration of Helsinki and the Guideline of Good Clinical Practice (GCP).

Before a clinical study can be started, approval for it must first be obtained from a recognised medical ethics committee as well as from the government (in Belgium this is the Federal Agency for Medicines and Health Products or the FAMHP). Both of the above-mentioned entities give recommendations and assess whether the new drug is safe and whether the benefits of the new drug outweigh the potential risks associated with the study. It is only after a favourable opinion (=approval) has been received that the study can be started.

The competent medical ethics committee watches over the participants’ interests for the entire duration of the study. The study can be stopped at any time, for example due to intolerable side effects.


What are the possible risks of participating in a clinical study?

First a study protocol is drafted for conducting a clinical study.  A clinical study’s protocol entails all of the study’s rules. This is the reference book or playbook, as it were, for correct conduct of a study. The protocol must always be approved by a medical ethics committee and by the respective government authorities before the study can start. The medical ethics committee also watches over the participants’ interests during the study.

Despite this, there may be risks or disadvantages associated with participating in a clinical study. A study’s risk profile is analysed by various parties (the company sponsoring the study, doctors, ethics committees and the government), and the study can only be started if the benefits outweigh the possible risks.

Risks/disadvantages can include the following:

  • The drug or treatment is usually new and is still being studied. This means that very often not all of the side effects of the drug are known. The risk of unknown side effects differs per study and cannot always be entirely predicted. That’s why the investigator gives the subject information about this beforehand.  Of course, all side effects are closely monitored by both the investigator and the ethics committees that watch over the safety of all participants. Moreover, a participant can decide to stop participating in the study at any time.
  • It is possible that the new drug may have no added value.
  • In phase II and phase III clinical studies the participant usually does not know whether he/she is receiving the drug or not. If it is ethical, the study protocol can specify a control group that will not receive the active product but a placebo instead.
  • Participation may require an extra effort of the study subject due to things such as additional hospital visits, exams or procedures (like the taking of blood samples).



Questions about your possible participation

Are you considering to participate in a clinical study? Click on the questions below regarding your possible participation.

Why should you take part in a clinical study and what are the possible benefits of participating?

  • By participating in a clinical study you support medical research, thereby contributing to the progress of medical science.
  • By taking part as a patient you can benefit from the most recent health care as well as a possible new treatment for your illness whose efficacy and safety are being investigated.
  • The results of the studies can also help future patients by developing a potential new drug, a new vaccine, a better diagnostic test, etc.
  • The investigator may perform more tests than what he/she would normally do in order to monitor the effects of the administered drug as closely as possible. You will not be charged for these additional treatments and/or tests during the study.
  • The studies are strictly confidential and your privacy will not be jeopardised at any time.

There is, however, no guarantee that your participation will benefit you personally. You must also take into account the additional effort and risks that might be associated with a study. The possible benefits, but also the disadvantages and possible risks of a specific study, will always be explained and discussed with you in advance by the investigator.

Who decides whether you can take part in a clinical study?

The investigator assesses whether you can participate in a clinical study.

Participating in a clinical study is always entirely voluntary. If you decide not to take part in a study, this will in no case affect your further treatment and will in no way impact your relationship with your treating physician.  You can also decide to stop participating in the study at any time.

You can find more details about our role in our referral policy. 

What happens with your data during a clinical study?

If you meet the selection criteria and decide to participate in a clinical study, your participation and all your personal and medical data will be treated confidentially in accordance with local laws. During a clinical study your data will be encrypted when collected and handled. These data will only be processed and analysed in a scientific context that is related to the study. In later scientific publications of the study results, no information will be shared which could personally identify the study participants.

At no time will your investigator share with C-Lys the medical data that are collected during a clinical study. C-Lys is only involved in the pre-selection of candidate subjects.

What happens if you suffer damage during a study?

Every clinical study is carefully designed so as to keep risks to a minimum. However, unforeseen problems cannot be ruled out. That is why the law states that the sponsor of a study is obligated to conclude insurance for every clinical study in order to protect the participants. C-Lys is only involved in the pre-selection of candidate subjects and is not responsible for your participation in the study. For more information about the insurance, you can contact the study’s investigator.

If you are interested in taking part in a clinical study, an investigator can explain the study’s objective and the possible benefits to you beforehand. Your doctor will also point out that such benefits cannot be guaranteed. Side effects can always occur due to the research phase in which the drug or treatment currently finds itself.

Will you receive financial compensation for participating in a clinical study?

Healthy volunteers who participate in phase I studies usually receive financial compensation that is calculated based on the burden caused by the tests (number of blood samples that need to be taken, number of overnight hospital stays, etc.) that you will undergo for the study. Financial compensation is usually not legally permitted for participation in phase II, III and IV studies as a patient. In some cases you may be entitled to reimbursement for your parking and travel expenses. In both cases the investigator of the study will be able to give you more information about this.

Financial compensation or reimbursement of expenses will always be paid by the sponsor of the study. Given that C-Lys is only involved in the pre-selection of candidate subjects, C-Lys is not responsible for paying compensation to subjects in any case.

Where do you need to report possible side effects?

When participating in a clinical study, it is extremely important to report any adverse reactions or side effects to your treating physician. This helps to ensure the safety of the drug or treatment.

This C-Lys website is not intended to report possible side effects. For clinical studies, a strict regulation is applicable to protect the participants. Because of this unique legal situation C-Lys employees can and must not answer questions about medical products, medical treatments, side effects, or specific clinical studies. We only have the information you can find on this site. Information on specific studies have been prepared in consultation with the researchers and approved by a competent ethics committee.

This C-Lys website is not intended to share your experience within a clinical study. It can be tempting to talk with others who are just like you participating in a particular clinical study. You could start telling about the possible side effects or about your experience, but it is important not to do this. After all, it could affect the outcome of the investigation. There is in fact something like the power of suggestion; hearing about a side effect may be enough to actually get this side effect.