additional navigation


You are here:

Stages of development

Before a medicine can be approved for the market, it needs to be tested for its safety, tolerability, and efficacy in clinical trials. These clinical trials must adhere to strict, internationally recognized guidelines, which have to be carried out due to specific procedures. The competent authorities and ethics committees have to give their approval in order for the clinical testing to begin.

Before the medicine can even be tested on patients, pre-clinical laboratory tests are performed to study the characteristics of the drugs. These test deliver information on the efficacy, tolerability, and dosage of the new medicine. Only those medicines deemed safe and promising undergo further clinical trials on patients.

Clinical studies

Phase I

During the phase I trial, drugs are tested for their safety and tolerability. The subject’s body is closely monitored in order to understand how the substances are being absorbed, and a safe dosage is established. Testing is usually done on a group of healthy subjects or on a group of patients with the disease that the drug is intended to treat. 

Phase II

The goal of this phase is to test the efficacy of the drug and to confirm the therapy concept. Based on the results of phase I, the dosage continues to be optimized and will be used in phase III. Testing will now also be conducted on a more limited and defined group of patients. 

Phase III

In this phase, testing is now performed in broad multi-level studies, while essential data are collected that will decide if the drug can be approved for market consumption. Study conditions will have also been introduced that are similar to future therapies. Testing is now done on a larger pool of patients, who are now placed into random groups. One group receives the new drug, another group obtains a standard treatment and a third only placebo drugs. This method of testing enables a clear comparison of the efficacy of the new drug. 

Phase IV

This phase consists of further clinical tests, which are performed with the now-approved medication. Since the study is now based on a population of patients instead of a group, rare side effects that are the result of a combination with other drugs, for instance,  can be recognized and registered.

AOP Orphan Contact

AOP Orphan Germany

AOP Orphan worldwide

Products & Area of treatment