Content - Trial types

Types of study

Clinical cancer research in the narrower sense is carried out in three stages, which differ in their objectives and the methods applied. Every new phase depends on the preceding phase and builds in the experience gained in this phase. The selection criteria for participation in a study in certain phases depend on various factors, including the extent of the disease, previous treatments and the general condition of the individual patient.


Phase I

The research in these first studies in humans is geared to finding new methods of treatment that hitherto have only been tested in the laboratory und in animal experiments. Phase I studies may also involve tests on new combinations of tried and tested treatments or investigations on previously approved treatments in a new use (indication). The aim is to find the best-possible route of administration and the best dose for the new treatment. Although many Phase I trials are carried out in healthy subjects, this is not usually possible with medicines for cancer, because these substances interfere in natural processes in the body and inevitably also damage or affect healthy cells. Phase I studies for cancer medicines, therefore, only involve patients for whose disease there is either not yet any treatment available or in whom the known treatment methods no longer help. When the questions of the Phase I study have been settled, the researchers move on to Phase II.


Phase II

In Phase II studies, the research is aimed at establishing how effective and how well tolerated the new treatment is for a specific type of cancer at the specified dose. These studies are also used to test drug safety and all the metabolic activities of the substance. If the treatment method proves to be well-tolerated and effective, the research moves to Phase III.


Phase III

In a Phase III study, the new treatment is compared with the conventional method, the standard treatment or the best recognized therapy, in order to find out whether the new treatment method has any advantages, e.g. better response of the tumour, longer survival, fewer side effects or improved quality of life. If an active substance makes it through Phase III, the results can be used to file an application for approval with the authorities. The marketing authorization or registration is usually also an essential prerequisite for ensuring that treatment costs are covered by the health insurance.


Phase IV

In the period after marketing authorization, rare side effects and interactions with other medicines are recorded. This enables the use of the new medicine to be optimized and allows it to be better tailored to different forms of the disease and individual patient situations. In Phase IV the researched treatment method becomes the recognized treatment standard in the fight against cancer.