Health, News March 30, 2007

Study Questions Application of Animal Experiments to Humans

by admin

Jonathan Latham and Allison Wilson

Much of science, including healthcare research and important fields of risk assessment, depend, in part or in whole, on the presumption that animal models can usefully predict human responses to treatments. However, relatively little research has been done to test this assumption. A new study has compared the results of animal experiments and human clinical trials. The study selected six treatments in which the human clinical trials had shown a clear result (either benefit or harm). They compared these to the results of animal tests. In three cases the results were in concordance while in the other three they were not.

The three treatments showing different results between animals and humans were

-Corticosteroids did not show any benefit in treatment of human head injury but did show a benefit in animals models

-The drug tirilazid worsened the condition of stroke patients. In animals it had successfully and significantly reduced infarct volumes and improved the neurobehavioural condition of the animals

-Antifibrinolytics reduced bleeding in clinical trials but data were inconclusive in animal studies

Results from animal testing are a key stepping stone in taking a drug forward for clinical trial. However, in the case of the six treatments reviewed in this study the animal tests failed to predict the effect of the treatments in human trials. This review provides some insight into the limitations of animal models and calls into question the extent to which they can represent disease in humans. The study has relevance to all risk assessments relying on animal models to assess human health impacts. These include risk assessments for pharmaceuticals, pesticides and GMOs when results need to be extrapolated to humans. These results broadly confirm a number of other studies.

Perel P, Roberts I, Sena E, Wheble P, Briscoe C, Sandercock P, Macleod M, Mignini LE, Jayaram P and Khan KS, Comparison of treatment effects between animal experiments and clinical trials: systematic review, 2006.

 

BMJ 334 (7586): 197-200 2007

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