Bayer and animal studies - Research

Preclinical:
Preceding clinical trials (in Latin, pre- = before). All studies and investigations in drug research which are performed before the start of clinical studies are referred to as “preclinical”.

Risk-benefit analysis:
An analysis to which all new drugs are subjected before they are first used in humans. It involves weighing the benefits and importance of the drug to the patient against the possible side effects and risks.

High-throughput screening (also: ultra-high-throughput screening)
Automated in vitro testing of substances for their effects in biological systems (cells, modified cells, enzymes). The tests are performed with the aid of computer- or robot-controlled processes. More than 200,000 substances can be tested per day in this way.

Clinical studies:
Phases in the drug development process in which the effects of a drug are tested in humans.
Phase I: Testing in healthy volunteers. Phase II: Testing in patients in order to demonstrate the efficacy of the drug.
Phase III (before authorization): testing in a large number of patients in order to test the safety of the effects and to detect side effects.
Phase IV: Additional monitoring of drug use after the drug has been authorized.

Summary of the usual procedure of drug research in the development of a new drug product.

The long search for new medicines

Replacement of animal studies with informative high-throughput cell tests

These days, the development of a new drug starts with the use of robots. At Bayer, up to 200,000 compounds are tested day by day in what is an extensively automated process to determine whether they could be used to treat a disease. Scientists talk about „High Throughput Screening“. To put it simply, this method can be compared with looking for a needle in a haystack - by the end, of the hundreds of thousands of substances tested, only a few will remain on which further research work can be carried out.

Additional data are collected on these drug candidates. These are obtained from tests on isolated cell and tissue samples. At the end of this lengthy weeding-out process, only a handful of promising substances usually remain. In the end, only these substances will be tested in animal studies.

Replacement of animal studies with informative high-throughput cell tests

	High-Throughput Screening More detailed information on the process

Safety for humans
Why are animal studies necessary at the end of this preclinical phase? Because these studies alone provide the scientists who are researching new drugs with a sufficiently reliable means of answering the most difficult question with which they are faced in their work: is a particular substance safe and effective enough for the next step - being used in humans for the first time? It is by no means unusual for the development of a drug to be abandoned on the basis of the results of these animal studies. On completion of the preclinical studies the benefit of a new drug to humans must be weighed carefully against the risk of possible side effects (risk-benefit analysis). If this analysis comes out in favor of the anticipated benefit, the new active ingredient may be tested in humans. In other words, clinical studies begin.

After authorization
Even after a drug has been authorized, its efficacy and safety continue to be monitored closely - in the form of post-marketing surveillance and long-term studies, for which patient data are evaluated. If these studies provide any evidence of new potential indications or previously undocumented side effects, further animal studies may be necessary. Because in our business, there is only one standard which applies - human safety.

Last update: August 03, 2005