What is a clinical trial?

Updated 16 April 2024

Clinical trials are tests of the effects and side effects of medicines

A clinical trial is conducted to find out how a medicine works, what side effects it has and how it is metabolized in the body. The medicines being studied can be both new medicines and known medicines already on the market in Denmark.

Medicine trials are conducted in different phases. Phases I, II and III are usually trials with medicine that are not yet marketed, where phase I trials include relatively few subjects and phase III can potentially include thousands of subjects. Phase IV trials are with medicines that are already on the market in Denmark. Read more here: ICH E8 General considerations for clinical studies - Scientific guideline | European Medicines Agency (europa.eu)


Volunteer participants test the medicine

Clinical trials can include either healthy volunteers or patient volunteers depending on what is being studied. All clinical trial subjects must receive both verbal and written information about the trial and give their written consent to participate before entering the trial. In exceptional cases, other forms of consent can be used, which you can read more about at the Medical Research Ethics Committees (VMK).


Clinical trials Clinical trials must be approved

In Denmark, clinical trials must be approved by the Danish Medicines Agency by the overall responsible person for the clinical trial (sponsor) making an application and submitting it to the EU portal (CTIS). When the application is submitted in CTIS, it is sent to both the Danish Medicines Agency and VMK. The Danish Medicines Agency makes a thorough assessment of the quality of the trial and the safety of the trial subjects. The VMK assesses the ethical aspects of the trial and the scientific basis, among other things. Before a clinical trial can start, both the VMK and the Danish Medicines Agency must have approved the trial. The authorization for the trial from both the VMK and the Danish Medicines Agency is granted in CTIS.


Inspection of clinical trials

The Danish Medicines Agency conducts inspections of clinical trials to ensure that the conduct of clinical trials complies with the granted authorization and the guidelines for good clinical practice (GCP). The Danish Medicines Agency carries out inspections of clinical trials of medicines in Denmark and abroad, including inspections coordinated through the European Medicines Agency (EMA). You can read more about GCP inspections here.


Adverse reactions in clinical trials of medicinal products

The investigator must collect and record adverse reactions according to the trial protocol. If serious unexpected side effects occur, they must be reported immediately to EudraVigilance (the EU adverse reaction database). The Danish Medicines Agency monitors these in EudraVigilance. You can read more about side effect management in clinical trials and how to report them here (in Danish).


Questions and answers

We have prepared some questions and answers about clinical trials with medicines, which among other things answer whether a specific trial should be applied for to the Danish Medicines Agency, which you can find here: Questions and answers 

If you do not find an answer here, you can always call us or send us an email. Our contact details can be found here.