Drug development phases

From medical need to novel medication

Development of a new drug must follow a multi-tiered process prescribed by legislation. It takes more than 13 years on average from the idea to the first market approval. The majority of this time is spent on studies to test the drug’s efficacy and tolerability and to determine the most appropriate administration protocol.

Preclinical phase

Medical need Target discovery Safety and efficacy
The focus is on the need to develop new medications for diseases for which no or only insufficient treatment is available so far. Based on the results of basic research, researchers identify therapeutic targets and develop corresponding active substances.  The newly developed substances are first tested for safety and efficacy in cell cultures (in vitro) and animal models (in vivo). 

Clinical phase

Phase I – trial in a small number of healthy volunteers Phase II – trials in a small number of subjects with the disease Phase III – trials in a large number of subjects with the disease
If preclinical testing was positive, the new investigational drug is tested in healthy adult volunteers. The focus of these tests is on the uptake and degradation of the new drug and the optimal dose.  Based on the dose determined in the phase-I trial, the new drug is tested in volunteers with the disease or condition. The focus is on the new drug’s efficacy (compared with placebo and existing drugs), tolerability, and dosage.  Physicians in many different countries test the new drug in a large number of volunteers with the disease or condition. This allows less frequent side effects to be identified. 


Evaluation by the competent authorities Use in patients Phase IV – studies after drug registration
Experts once again evaluate the results of all trials. If the evaluation leads to a positive result, the drug can be approved and can henceforth be prescribed to patients.  Physicians, authorities, and the manufacturer monitor the drug’s performance. The package insert, for example, is updated whenever needed.  The drug is tested in further studies, for example to investigate interactions with other drugs or to find out whether it can be used in the treatment of other diseases as well.