27. September 2023

Why are preclinical studies required for the development of drugs and why are clinical studies in children so important?


Before drugs and treatment options are officially approved, they must ultimately be tested on humans in a final phase by means of so-called “clinical studies”. Before that, the first step is to conduct “preclinical studies”.

What exactly are preclinical studies?

Preclinical studies or “preclinics” are a phase in drug development in which new active substances are tested in cell culture or animal models. They are also called “preclinical or nonclinical research”. Preclinical studies (in the laboratory or using animal testing) are used to provide initial indications on the tolerability and dosage as well as on the mechanism of action of a new drug substance.

The goal is to obtain drugs by means of cell culture or animal testing, without exposing humans to potential risks. Clinical trials involving humans will only be conducted if no dangerous adverse reactions occur and it is believed that the medication will be effective.


Once a preclinical study has been successfully completed, the drug can proceed to the next phases:


Phase 1:
Pharmacokinetics (active substance is tested in terms of absorption, distribution and excretion; active substance is administered to healthy adult volunteers under strict medical supervision.) When it comes to children, pretesting on adults is used wherever possible. Some drugs, e.g. cancer therapies, cannot be tested on healthy subjects. In such cases, volunteers are invited who are affected by the disease. It is also not possible to test genetic therapies or enzyme replacement therapies for metabolic diseases on healthy subjects: in these specific situations, young patients are also invited to participate in such studies, which promise to be innovative to improve medical conditions where no suitable drug is available. 

Phase 2:
Determination of dosage & verification of tolerability (initial testing of active substance on patients). Phases 1/2 are often scheduled to be conducted sequentially within a study.

Phase 3:
Evidence of therapeutic efficacy (active substance is tested on as many patients as possible). However, in the field of rare diseases, the case numbers are considerably lower.

Phase 4:
Clinical examinations after drug approval: in this case, follow-up examinations are conducted on the basis of prescribing practices across a broad range. General importance of clinical drug studies in children 

A child’s organism, which is still developing, differs from that of an adult, which is why drugs may have different effects in children. This explains the importance of drug studies in children and adolescents. However, the younger and sicker children are, the fewer tested and approved medications are available for their treatment. A large proportion of the drugs currently used in children have never been tested in children or approved for use in children.

The backlog of drug studies in children is therefore large.

In this context, it is especially important for all drugs to be tested specifically for this age group, in order to systematically determine the dosage to be administered and the effects they can have in children.

OKIDS provides support by coordinating paediatric drug studies


This is precisely the problem OKIDS addresses by coordinating joint drug studies in children within an established paediatric research network including experienced children’s hospitals and universities at six locations throughout Austria. The advantage of this network is that paediatricians can pool their experience – on the one hand, this allows the best possible standard treatments for children in consultation with the centres, and on the other, new treatment options can be tested in close cooperation between the centres and international networks.

Children participating in a study receive excellent medical care, and the young participants’ safety is given top priority. Often, such studies allow children to gain access to new treatment options and medications that would otherwise not be available to them. This is particularly important in case of children for whom the currently available treatment options do not work or do not work sufficiently.

OKIDS has established a forum of experts consisting of Austrian paediatricians to ensure a focus on drug studies in order to improve the most urgent treatment deficits for children.

With support via public funding, OKIDS provides organisational structures that enable drug studies to be conducted safely, efficiently and in an acceptable way for children as part of the requisite treatment.


Learn more about OKIDS