Betrokken en zorgvuldig - Kennis maakt ons beter

General information


Clinical trials are conducted to develop better treatment options for diseases. The researchers investigate if a new treatment is safe and effective. Clinical trials can only be conducted with the help of subjects. These can be patients or healthy volunteers. The collaboration of patients is necessary to investigate the effect of a treatment. A clinical trial is also called: clinical research study, research study, scientific research study, medical research or medical experiment.

Why participate in a clinical trial? 

Medical research enables us to apply new and better treatment options. Medical research is required to prove that a new drug is safe and effective, before it can be marketed for sale. Without medical research we are not able to develop better ways to prevent, diagnose or treat cancer. Often medical research can only be conducted if patients are willing to participate. Sometimes participation in a medical research study has no direct benefit for a patient. In this case a study may help future patients. This can also be a reason to participate.

Risks and side effects 

The treatments in a research study are new and the side effects are not yet known. One of the objectives of a research study is to investigate the effects of a treatment. Therefore there may be some unknown or unforeseeable risks for a subject participating in a clinical research study. The risks are depending on the treatment type and the condition of the subject. The study physician will check you regularly to see what effect the medication is having on you. In addition the study physician will inform you about potential risks and side effects of the research study in which you are asked to participate. Before you decide to participate you will have to consider the potential risks and benefits of participation.

Clinical research  

Many patients are being asked to participate in a research study. A clinical trial is one of the final stages of a long and careful cancer research process. If it becomes clear from a laboratory research study that a new drug may be effective, investigators will test the drug in animals to see whether it is effective and safe. Only if animal studies show that a new drug is effective and safe, the drug will be investigated in humans. This means that a lot of research is being done, before humans participate in a clinical research study. 

Research in humans is conducted in different phases. In the early phases investigators enroll healthy volunteers and/or patients into small pilot studies initially, followed by larger scale studies in patients that often compare the new product with the currently prescribed treatment.

Study design 

During a research study investigators often compare a new treatment with an existing treatment. Therefore subjects are assigned to different treatment groups by randomization. Subjects are randomized in clinical trials so that bias does not weaken the study results.

In a randomized trial, investigators use a computer program or a table of random numbers to assign each study participant to a group.

Sometimes an investigator would like to know if the effect of a new treatment only depends on the new treatment itself since several factors can play a role.Therefore the new treatment is being compared with 'no treatment'. This means that one patient group receives the new treatment and the other patient group not. In order to compare the new treatment with 'no treatment', investigators use a placebo-treatment. The placebo looks exactly like the new treatment, but has no active substances.

Ethics committee

The Medical Research Involving Human Subjects Act (wmo) requires that research proposals may only be carried out if a recognized review committee has approved it. Many hospitals in the Netherlands have such a review committee. The VU University Medical Center also. The committee reviewes among others: 
- if the clinical trial is relevant; 
- if there are not too many risks and/or disadvantages for the patients; 
- if the written information for patients is sufficient. 

If the committee believes that the potential risks of a research study are not in proportion to the potential value of the research, the research study will not be approved. This means that an investigator cannot conduct the study; the study should be amended first.

You are asked to participate 

You are being asked to participate in a clinical research study by your treating physician or another member of the research team. Your physician will discuss the study with you. You will receive the information also in written, so you can read it at home. In addition, your physician will explain all your rights and responsibilities. You will get sufficient time before you decide if you would like to participate or not. Read all information carefully and consider all procedures, benefits and risks, discomforts and precautions. Ask as many questions as needed. If you are willing to participate, you will be asked to sign the consent form. You may withdraw from the study at any time.

Your rights and responsibilities 

Guidelines have been developed to protect subjects participating in a research study. There are strict rules for research physicians conducting clinical research. The most important rights for subjects are summarized hereafter.  

Right to decide about participation (voluntary participation)
It is up to you to decide whether or not to take part in a clinical research study. It will always be your decision.

Right to receive information and ask questions
Your physician will inform you about the clinical research study, verbally and in written. Not only prior to study start, but also during the course of the study you have the right to receive information. Your physician should provide you with the information.

Right to withdraw from the clinical trial
Even if you have consented, you can withdraw your consent at any time. Also if the study has already started, you always have the right to withdraw from the study.

During the course of the study the investigators collect data. The collected data will be handled confidentially and the data will be assigned a code number. Your data will also get a code number and your name will be removed. If the results of the study are published, your identity will remain confidential.    

What will I be responsible for if I participate in a clinical research study?
You also have responsibilities as a subject. In some research studies you have to stay sober or bring all remaining medication with you to a visit. If you are not willing to follow the instructions of the physician carefully, the research cannot be conducted the right way and the collected data is not reliable. If this happens your physician may end your participation and discuss further treatment with you.


Investigators try to prevent that something goes wrong during the course of a clinical trial. Also the ethics committee will look on measurements taken to prevent any damage. Nevertheless unforseeable injuries may occur. The pharmaceutical company or hospital conducting the research has taken out an insurance for the study. This insurance will compensate you for any possible damage as a result of your participation.


Some people would like to know who has initiated the clinical trial or who will be the owner of the data. You can ask your physician for this information. There are several possibilities:

1) The clinical trial can be initiated by a pharma company or company that manufactures medical instruments. They have developed a new drug or medical instrument that has not yet been marketed for sale. First it needs to be investigated if the new drug or medical instrument is safe and effective. The companies ask physicians if they would like to investigate this.   

2) In addition special research centers or institutes can initiate a clinical trial. Also a department of a hospital can decide to conduct a clinical trial.

3) Many research is being conducted in University Medical Centers.

Contact for patients

For more information about participation in a clinical trial, please contact your treating physician.

Referral information 

For referral of patients for participation in a clinical trial please contact the Principal Investigator at tel. +31 20 444  1295.